2000+rpm hesitation... fuel pump?

[britlude]

hi all, merry xmas/happy new year....

as it's coming to the end of the xmas break, it seems my car has decided now is the ideal time to have a hiccup....

when cruising at lower revs, 1500-2000, if i gently accelerate , the car is hesitant, 'fluffy', and doesn't really want to do anything....

i suspect its fuel pump related as when i get to 4500 rpm it takes off like a scalded cat! i'm guessing it's associated with the fuel pump resistor.... i did think pump, but when that gets the full power post 4500(ish) rpm, there doesn't seem to be any lack of oomph, so the pump can keep up with full power at the lower half of the top end rev range....

tomorrow i shall try the fuel resistor bypass trick, just to see if that removes the problem and go from there.... check the resistor value and connection leads....

(i'll order a new fuel filter in the mean time and sort out a pressure gauge for the fuel system)

depending what the resistor reads on the meter, i may be looking at a new fuel pump to fit in the spring.... any recommendations as there's a variety of non-oem options... normal use, rather than race! (circa £100 for a pump, rather than £400 for the OEM pump and the bracket, when i already have the bracket seems excessive!)

[goldnsx]

Nothing more to add as I guess you're on the right track. Bad o2-sensors could result in a similar hesitation. Bypassing the resistor will tell you. There are plenty of options out there, some better, some less. They all need more current. So make sure you'll upgrade the OEM wiring if you don't go with an OEM pump. I prefer a Denso pump as it offers OEM quality but I didn't find just the pump. But I'll guess there should be a substitute. Whatever you do DO IT RIGHT (new gaskets...) as the labor is pretty timeconsuming...

[britlude]

found this comparison, discount the bosch as that's not in tank! http://realstreetperformance.com/Fuel-Pump-Comparison-Test.html


and SOS... https://www.scienceofspeed.com/index.php/walbro-255-lph-high-pressure-fuel-pump-nsx-fitting-kit.html

[Hagasan]

found this comparison, discount the bosch as that's not in tank! http://realstreetperformance.com/Fuel-Pump-Comparison-Test.html


and SOS... https://www.scienceofspeed.com/index.php/walbro-255-lph-high-pressure-fuel-pump-nsx-fitting-kit.html

Hi Jonathan, if you need a pump and want to go the Walboro route I have a brand new one I bought from SOS that I've never used. Still in packaging. Just let me know if you need/want it.. I'd have to check the box in the loft or my receipt as I can't remember if I bought the fitting kit they also sell

Cheers,

Gary

The reason I didn't use it is because of my SC kit. One of the Dutch guys had an issue because of the better flow rate which messed up his mapping. He also had an SC. I just erred on the side of caution and stuck to OEM as my setup was similar to his..

[goldnsx]

I also had the Walbro (from SoS) and had bad luck. I've bought two of them, one for me, one for my friend. Too bad I didn't give him the loud buzzer. :) His one was quiet while mine made noise to the extend that I went for the Denso Supra in the end which is very quiet and OEM quality. I've just had bad luck with the Walbro. With a very loud exhaust I might have left it in.

[NSXGB]

Rock Auto seem to stock a Denso pump.

[britlude]

made myself up a jumper link today and took it for a drive... unfortunately it's currently an intermittent problem so not sure it was actually doing it today..... i shall have to take it for a longer drive tomorrow...

in the mean time i did give the inlet a quick clean (wasn't too bad)
https://farm5.staticflickr.com/4733/27619257799_0c33b38af6_c.jpg (https://flic.kr/p/J5BV6Z)WP_20171230_12_30_18_Pro (https://flic.kr/p/J5BV6Z) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

and cleaned the air filter (K&N) and re-oiled it....
https://farm5.staticflickr.com/4731/39396500381_1f1394e38f_c.jpg (https://flic.kr/p/232kn1z)WP_20171230_12_23_36_Pro (https://flic.kr/p/232kn1z) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

...odd that it had a clear bit.... still, it's a K&N, at least i have the option to clean it!!!

ordered myself a fuel pressure gauge/kit to check the pump health!

]

[britlude]

took it out today and drove until it started to stutter/fluff..... stopped and put the relay jumper widget in and continued... the same piece(s) of road were fine, no fluttering.... so just to double check I swapped it back to the resistor and set off on the same roads...... it was ok.....

so....... is the resistor having issues when it gets hot (which it was) and after the swap out had cooled, and once swapped back hadn't had enough time to get back up to faulty temp?? i'll order a new resistor anyway.....

i also found the recent wet weather had caused the car to get damp/steam up again... tracked it down to the thin rubber seal/edge/trim between the moulding that goes over the door and the roof... the one that SOS charge $40 for, but then want $53 to post it on the slow boat, when I know it'll fit into a big jiffy bag! and it's not actually the right one for over-the-top fitment.... https://www.scienceofspeed.com/index.php/scienceofspeed-window-trim-seal-kit-nsx-1991-05.html

when the rain is sufficient to drench the roof, the water can get under this seal, then onwards getting behind the rubber on the b post... then down the door pillar...

new mouldings seem to be discontinued, but are way over priced! unless there's good s/h hands out there at a reasonable number!! not found any so far!

i've also sourced some waterproof foam that goes inside the over-door moulding... if the moulding have ever been off, it'll probably be useless anyway (same sort of deal as the rear light seals)

i'll probably have to order the resistor from SOS to try and dilute the shipping, but of course it's sunday and B/H, they don't have it listed on the site, so can't get things underway.

[Hagasan]

Jonathan, why don't you just get the parts from Marc Perez.. Sure it'll be cheaper for both the part and shipping? It'll cost what you say it costs if you get my meaning..

[britlude]

SOS had the rubber extrusion made, so can't get it anywhere else.. tho it has to be modded to work where i want them....but i'm working on it! i've ordered from Marc before, i know what you mean!

i've also found a place over here with VERY competitive pricing... just waiting for confirmation, and to find out what the catches are!!!




does anyone know what the resistance should be of a good resistor?? can't find any mention anywhere

[Kaz-kzukNA1]

does anyone know what the resistance should be of a good resistor?? can't find any mention anywhere
[Edit: found your question after posting my original reply below....]
0.55 ohm at room temperature for your NSX.
0.32 ohm at room temperature for 97+ models.



Hi, Jonathan.
Can you re-create the same issue at idle rpm or raising the rpm while in P position?

It depends on the failure mode but if the fuel pump resistor block intermittently fails, you will have problem starting the engine or even keeping the idle rpm.

Therefore, it could be not related to the resistor block.

For your reference, the most common failure modes are;


the internal crack of the resistor (you can't see it from outside). You may be able to re-create the same issue by spraying the ice cold spray.



the intermittent damage to the crimped section of the wire just at the edge of the resistor terminals.


Example here;
http://www.nsxcb.co.uk/entry.php?2057-Fuel-Pump-Resistor-01

http://www.nsxcb.co.uk/entry.php?2058-Fuel-Pump-Resistor-02


If you can easily re-create the same issue, may be you can borrow the good resistor block from another owner?

I have two new resistor blocks at my place.
If it is in stock in Japan, I can release one of them for you but Honda Japan is closed for the new year holiday until 4th and then they will need some time going through all the email so won't get reply for several days.


I have one used resistor block with damaged wires.
If I can find suitable terminals, I can create temporary resistor block for you.
You are more than welcome to try it first before buying the new one, although it's not mega expensive so might as well replace it with new one if you are still using the original one.


If you can drive up to Bucks and if you are using the OEM fuel filter fitting, then you can use my fuel pressure gauge as well although with your issue, may not fancy driving the long distance….


Probably you will need measuring the fuel pressure while the issue is still there any way.
You can't rule out the fuel pump yet....


If you can re-create the same issue at idle rpm (closed loop once warmed up) but not getting the CEL, the fuel pressure is not low enough for the closed loop fuel control to max out on the trimmer.
There is no PF compensation in the closed loop calculation on our NSX.
Pressure regulator can fail but you will see on the pressure gauge.
Hope you can measure the fuel pressure while the issue is still there.....


Kaz

[britlude]

i've just found your threads on this issue, and the appropriate pic to answer my first question....

https://lh3.googleusercontent.com/jrNyjkTG6X3r0s7AZfrdK3yt1LVlMApFkfGgzXhf7sm_C2w3yZ xw7c3hTAcdUJKnbabmqb6kSIg5tsbDkuwrS0G7x38rEsgc6E-t6tWN66VIT0Rrp79Lpgrwa3uyQqoCdF-72fHh9i7yTfq3gj5WjoZMGVpoIDGr26Tlo_IJE9X_Qxr33ljj4 NckZjstb0oI5Dc-4P2JchrCnb4oyD0Yoo-ACpGpDK3Af-dbTncNZAL5PLOlyEYfA2MUH3PwHgHPAzTZEg2Osigyiw3BScoE 3TtSYSZHkf3rTREbIsmDC-lhCa2jZEau5J05AB68tEkdrHDwrARh7kEPcbojBnx8TThijcEq l8dBScuOcnQ5Po7sEaiRHWNLRS9y7SpPnpEMJSZUfZhJPci0O3 pwcnZPyrkmHCQIwKioY-b3mH61MuTUOk4aT869PiUAMfHTJ07dhvrWo42KzJrPCRmJgFjz x4xtvkxls-5ECY6y3lagFgFiEBlP_G30odyldh5ZXQzyy5b_GZ8lKAuoHSsR iwPgBJqGk9CO8lUNW-r5g1i8BSlWCB3p1RofZW_TVrbmWsvZUJnKPsrWWMKvYRun4jnY KmOW1SDaUBPXM8la3i-qmNDUm7Vmthjavg=w1080-h810-no


ironically i have to drive to birmingham next weekend, but don't tell Sarah, it's her birthday surprise, so i'm just covering all the options... if the problem does reappear i'll be shorting the resistor for the time being whilst i wait for email replies/deliveries.. i have a pressure gauge/etc on it's way, but of course that won't be here until after next weekend....

[NSXGB]

Jonathan, if you need one in a hurry, or find they are on back order, I've got a new one you can have until the new one arrives.

[britlude]

re. rubber seal over the door, fitted to the door 'moulding'...... studied my Baines rubber extrusion catalogue at length, working out the ideal 'replacement' (not that any are a direct replacement) and found one suitable... not on their 'normally stocked' list.... you guessed it, not on the shelf, and min order of 300 metres!!! bum... so another search, found a supplier in southampton.....

....a a quick call, 'oh we don't keep any extrusions', oh i say, do you get them from Baines... 'yes' came the reply......

looking increasingly like the SOS rubber, unless i can find where they get it from.....

[sorepaws]

How much do we need to get to replace all the seals on the members cars ? And then Jonathan how much will you charge us all to fit them ? - Your new business opportunity in 2018 - Happy New Year BTW

[britlude]

too late.. i've ordered 2 sets of the rubber trim lengths from SOS.. (one set £78, 2 sets £101 plus border ransoms!) so i may have a set to sell on later.....

i've just ordered some oem bits from an untapped UK source, pricing looks good, we'll just see what the service is like! :)

[britlude]

right where were we??? ah yes, waiting for a pressure gauge set to turn up... and while i was away for my girlfriends birthday surprise (Blue Man Group in Birmingham) it arrived.

the plan was to take the NSX and arrive all relaxed and fresh, but that plan went out the window....

we set off, not going mad, cruising at about 2600-2700 prm, after about 30 miles the car started to feel fluffy, getting progressively worse, driving progressively slower until we got to an exit on the M25 (A127!) just before we got there it had a big stutter and the warning triangle came on on the dash!!! panic! fortunately it went out as i lifted the throttle.... luckily it was a roundabout junction, so i could stop somewhere safe and do a quick fuel resistor bypass...

resistor bypassed, and car restarted, all seemed well, so gingerly carried on....

another 10 miles on, it did the same, coughed, stuttered, red light on dash.... pulled onto hard shoulder, this time at the exit of the first tunnel anti-clock from Dartford crossing.... LUCKILY (tho not realising it at the time) this was the last bit of hard shoulder as the M25 then turned into 'smart' motorway..... anyway, stopped, light went out, engine responding ok to throttle inputs, so decided to abort mission as there was another 125 miles to go, so gently took it to the waltham abbey turnoff and headed back, finding slow vehicles to slot in behind and kept it just over 2000rpm...

it got back with no further issues..... bearing in mind we were now back in rochester at 10am, and the surprise was in Birmingham at 4!!!! car was fine, i was panicking! hopped into the cube and trundles up there without incident (apart from the debris of a big porsche and a small estate when the porsche had decided to overtake something, not looked in his mirrors and sideswipes said estate with his back drivers quarter.... we presume it was the porsche at fault as he was driving like a moron when he overtook us minutes earlier)

Blue Man Group was excellent, and the surprise a success! if you ever get the chance to catch them do-so! just don't turn up late, they give late-comers some very special attention!

right back to the plot.... pressure gauge connected (bearing in mind the car's cold, pump's cold, it's all cold)
this is what i have..... (psi)
https://farm5.staticflickr.com/4690/38662548685_998878f953.jpg (https://flic.kr/p/21UtEJZ)pressure readings2 (https://flic.kr/p/21UtEJZ) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickrpressure readings (https://flic.kr/p/Jk1L8P) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

blipping the throttle with the fuel resistor in line gave a 40 up to 45 to 40 pressure boost as expected, and without the resistor 42-50-42 again as expected


the light on the dash was the top right......
https://farm5.staticflickr.com/4733/38849535364_78eab4244f_c.jpg (https://flic.kr/p/22c12nf)WP_20180107_15_14_03_Pro (https://flic.kr/p/22c12nf) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

i'm hoping the light comes on when the computer runs out of adjustment for the pulse width on the injectors, ie. the engine is still lean on the O2 sensors even tho the injectors are at 100%...... and when i was stationary or off the throttle, the fuel pump could catch up, pressure restored and all is well....... there was no mention of that dash light coming on, only related to the hazard switch! mine being JDM doesn't flash the dash light with the hazard switch anyway!

next is to drive it around til it starts to exhibit the symptoms and pressure rest again! it also means i can use some of the FULL tank of petrol (in anticipation of a drive from home to birmingham and back!)

[Kaz-kzukNA1]

https://lh3.googleusercontent.com/EN0YQre7GKScfQTxFP51qbupvyU_Nx5_Gt4yPCx4JsPhQsNaBf nNgDlYYeYi3mytM4zSkFg6y5KWgmNphJdymW22BfZfmAMG8CaU Dc7JWvactZUpYNUqv57aPvwJj0C0Wf72HLIfXRI3XhlvZJynQV viljNGjGKPzjGoEkXul7yO5nxBCJ7nkpHqTFnRb2naygmkcauV XGZ1Ist234NhgVtvlFeLjGQQcx-BgRUd53hyPtFdLQfimv48vq4RJNdiVag2HyfPYK3u8Dexu86YU oATpvk2w0FKZrZVvarZ92PUhe4vH5DWf6_rK3Z2-7Blu4bSgyB8xieFhLf3RalFEuIBIoBezKVMhLy27bb1iYa9mCB IGirK9vyODYwTmHfkoHrGSl1q6DGuzmRfuN1J__Atm_HetOjYt 2--XUOorVD3jrxQwJ8mXj1dLytqrf6b2TnrQ3P1psQIXy6HNkV6R3 QJhyk2KblEQqp5Otvc7ifePqlodndi5xgUFFY97-pZ1kTF5FjB5FDHd0D8vYxeO8oR9C4VW9L_mSuZrQFjyHmGJLr9 uUgKm2joNB2xTVSJVIRqXwp4i5m5ip7QRY5bnO-h9C3W0twpDSMUqLx7=w1080-h608-no
Hi, Jonathan.

Looks like someone replaced your gauge plate.
With JDM, where the triangle marker sits on your gauge, it should show the marker for the CAT high temperature warning.
It's ' sort of ' equivalent to the rapid blinking CEL on full OBD2 car when too much unburnt fuel entered the CAT.

Are you still using the JDM spec CAT?
There is a silver stick like temperature probe on each CAT.
The mating connectors are mounted next to the RR w/speed sensor behind the boot carpet at the forward right corner of the boot.

Please note that if you have ACG charging system failure, both the battery marker and this CAT high temperature warning will be triggered at the same time.


Please do not keep running the engine at the same load for long period when this warning is triggered.
Otherwise, it will melt down the honeycomb structure inside the CAT body.

If you saw it while driving, please slow down (like 50% of the speed you were carrying) until the warning light disappears.
If it happened at idle rpm, please park the car where no flammable materials are under the car and stop the engine for more than 10min to cool down the CAT.


As you suspected, you really need to measure the fuel pressure while the issue is present otherwise it could lead to wrong diagnosis.

If the fuel pressure is fluctuating but not enough to trigger the CEL, then due to the delay in O2 feedback control loop and only two O2 sensors for 6 cyl engine that several cyl will be getting very rich mixture.


Or, you may not have fuel pressure issue but instead, having intermittent multiple cyl IG issue due to ignitor failure, IG coil, etc resulting in misfire that is not consistent enough to trigger the CEL and allowing so much unburnt fuel entering the CAT.
Even with the full OBD2 spec ECU with 3pin IG coil and misfire detection module (yours is pre-OBD2), I know from the fact that it couldnÂ’t detect intermittent misfire caused by the IG coil triggering rapid blinking CEL but no continuous CEL and thus, no error code despite the big misfire that anyone can feel.


If O2 sensor is sending intermittent wrong voltage data, again, it could result in similar issue without triggering the CEL but normally, it's hard to make the CAT so hot without triggering the CEL if the issue was caused by the O2 sensor.


Still, there is a chance of multiple issues of mixture and IG....


Again, hope you can measure the fuel pressure while the issue is happening on the engine.


Kaz

[britlude]

very interesting Kaz.... when i got my car, way back when, that particular legend section was missing on my car... whoever did the 'MPH' conversion managed to lose that particular transparency (along with the trip reset button, later found under the carpet!) and i made a replacement from the legends in the handbook i had... obviously the UK handbook wasn't correct for the JDM car!

I am still running the JDM cats, and indeed have the 2 temp probes still there, all present and correct with the cables running into the boot area (next to the CD player location) and it would seem they are still functional! which, in this case, could be a huge clue in finding the cause of this particular issue!

when the light came on, don't worry, i slowed down immediately, stopping where safe!!!

i haven't noticed black smoke from the rear, and i haven't got sooty marks on the exhaust tips or the rear of the car, so i doubt it has been running rich, so i'm leaning toward an ignition issue (ok, the weather and thought of being under the car this time of year may be affecting my leanings! lol).....also the issue happened with fuel resistor in-line, and shorted out, both at the same sort of revs....

looking on NSXprime ignitor issue threads, it seems to be highlighted when under load, and it seems i am more likely to reproduce the issue when the car is warm and i am going up an incline, loading the car more... both occasions on saturday were on a motorway incline.

i shall try to fit the pressure gauge in a viewable position and see if i can reproduce the fault state and monitor the pressure.... i might also run some wires from the coil feeds to a line of LED to give a visual indication of the coils being driven... whether i'll actually be able to see any breakdown in the fast strobes i don't know, but it is a theory!

having seen the prices of ignitors, i was toying with the idea of the bosch COP upgrade developed 'open source' by Operator on NSXprime ( http://www.nsxprime.com/forum/showthread.php/196051-Bosch-cop-coils ), and now supplied by A.S. Motorsport.... basically using modern COP coils with the trigger circuitry built in to convert the ECU signal levels to drive the coils.... removing the ignitor and gaining 25 years in automotive development....

I shall see what i can find.....

[britlude]

quick update..... 2 second hand ignitors on their way..... one from Germany, one from USA... if it is the ignitor it could leave me stranded, so a couple of, maybe ok, cheap spares as insurance to buy a bit of time! if it is the case, then i can buy a new one or upgrade accordingly


(lings only want £520 for one!!!!)

[NSXGB]

https://lh3.googleusercontent.com/EN0YQre7GKScfQTxFP51qbupvyU_Nx5_Gt4yPCx4JsPhQsNaBf nNgDlYYeYi3mytM4zSkFg6y5KWgmNphJdymW22BfZfmAMG8CaU Dc7JWvactZUpYNUqv57aPvwJj0C0Wf72HLIfXRI3XhlvZJynQV viljNGjGKPzjGoEkXul7yO5nxBCJ7nkpHqTFnRb2naygmkcauV XGZ1Ist234NhgVtvlFeLjGQQcx-BgRUd53hyPtFdLQfimv48vq4RJNdiVag2HyfPYK3u8Dexu86YU oATpvk2w0FKZrZVvarZ92PUhe4vH5DWf6_rK3Z2-7Blu4bSgyB8xieFhLf3RalFEuIBIoBezKVMhLy27bb1iYa9mCB IGirK9vyODYwTmHfkoHrGSl1q6DGuzmRfuN1J__Atm_HetOjYt 2--XUOorVD3jrxQwJ8mXj1dLytqrf6b2TnrQ3P1psQIXy6HNkV6R3 QJhyk2KblEQqp5Otvc7ifePqlodndi5xgUFFY97-pZ1kTF5FjB5FDHd0D8vYxeO8oR9C4VW9L_mSuZrQFjyHmGJLr9 uUgKm2joNB2xTVSJVIRqXwp4i5m5ip7QRY5bnO-h9C3W0twpDSMUqLx7=w1080-h608-no




Noticed this symbol on mine the other day when I put my hazards on, I have the Early Type R dash bezel. I wondered what the symbol represented. My 'TCS Off' is blanked out too. I wonder if there are any other 'anomalies'?
I'll do you a swap if you want Jon.

[britlude]

there seems to be some different tweaks then!... no good to me, I want TCS too lol... but thanks for the generous offer!

[NSXGB]

... Ah yes, I suppose all three are joined so no good at all...

[britlude]

well my cunning plan for getting a new OEM honda bits supplier has gone pear shaped......

a couple of part number searches on google/etc had popped up https://www.fowlersparts.co.uk/ with some good pricing, so thought i'd give them a try.. ordered the top screen moulding and retainer and the gasket for the fuel pump..... as that was on my to-do list..... all ordered thru the website on 3rd Jan, 7-10 day delivery, blah blah, order confirmed!

this morning i got the email....

Dear jonathan,We are pleased to inform you that your recent order is on it's way.
If there is no one available at the nominated delivery address to receive your parcel and it is too big to fit through the letterbox, a card will be posted through your door with instructions on what to do next.
Please ensure you have read our FAQs (https://www.fowlersparts.co.uk/index.php/about/faq) if you have any queries.
Kind regards,


The Fowlers of Bristol Online Team

followed later by

Hello

The following items are car parts and cannot be supplied by us as a result:

Part no: 73151SL0023
Description: Molding, Fr windshield upper
Ordered on: 03/01/2018

Part no: 73152SL0013
Description: Fastener, Fr windshield upper
Ordered on: 03/01/2018

They have been cancelled from your order and the value refunded to your card.

Kind Regards

Order Amendments Team - spares@fowlers.co.uk


hmmm... gits..... i presume the dispatch note is for the gasket, and they held the long thin boxes..... no mention of restrictions on honda part numbers, and again, gits! you just know they have 2 long boxes sitting there waiting to go back to the honda warehouse! oh well, another loss for HUK sales, they really don't do themselves any favours!!

if you really want to depress yourself, they list the NSX fuel pump 17040-SL0-A30 complete at £191.68, plus postage!

and their reply to my say-what???? email.....

Hi Jonathan

Apologies for the confusion.

As we are a motorcycle dealer, we are not franchised to sell the vast majority of the Honda car parts range. Some of the parts appear on the system as part of the main Honda database, and we have asked for these to be removed so that they cannot be purchased.

The system does not know you are ordering car parts - we only find out it is an issue when the order is sent to Honda and rejected on the basis that we are not permitted to supply those parts.

The other part on the order has not been cancelled, suggesting it is not exclusively a car part, and this has been supplied to you.

You will need to contact a supplier for Honda car parts to re-order the parts that have been cancelled. I suggest you do not attempt ordering any other car parts through our website to avoid any further disappointment.

Kind Regards
Sam


i've asked how they can quote prices sooo much better than HUK car parts counters..... or if that's the reason they can't supply!!!! lol

[britlude]

3 threads in one here..... re. ignition upgrade with bosch COP units....
https://www.ngk.com/data/default/images/watermarked/450/NGK48728_d.jpg

6x NGK Ignition Coil - U5014 best price so far.... 6x £22.90 £137
6x connectors for coils, lots of choice! £10-£20
honda connector to make it plug and play circa£9 (for a M-F pair, not just the one i want!)

plus some wires, sleeving and some heat shrink.... so well under £200 for the bits.... hmmmm

[NSXGB]

3 threads in one here..... re. ignition upgrade with bosch COP units....
https://www.ngk.com/data/default/images/watermarked/450/NGK48728_d.jpg

6x NGK Ignition Coil - U5014 best price so far.... 6x $22.90 £137
6x connectors for coils, lots of choice! £10-£20
honda connector to make it plug and play circa£9 (for a M-F pair, not just the one i want!)

plus some wires, sleeving and some heat shrink.... so well under £200 for the bits.... hmmmm

Will be looking forward to your "How to" thread.

[britlude]

well... looks like it'll be cheaper than a new ignitor!!!! lol

[UnhuZ]

Hi,


3 threads in one here..... re. ignition upgrade with bosch COP units....
https://www.ngk.com/data/default/images/watermarked/450/NGK48728_d.jpg

6x NGK Ignition Coil - U5014 best price so far.... 6x £22.90 £137
6x connectors for coils, lots of choice! £10-£20
honda connector to make it plug and play circa£9 (for a M-F pair, not just the one i want!)

plus some wires, sleeving and some heat shrink.... so well under £200 for the bits.... hmmmm

don't quite follow what you are doing with this...
using NGK coils on the NSX ?? are they compatible??
(i'm not talking about connector, but functionality)

Thanks,
Nuno

EDIT - ohhh... yeah... the image is blocked to direct link use ;)

[britlude]

Hi,



don't quite follow what you are doing with this...
using NGK coils on the NSX ?? are they compatible??
(i'm not talking about connector, but functionality)

Thanks,
Nuno

EDIT - ohhh... yeah... the image is blocked to direct link use ;)


replicating this, originally designed 'open source' on NSXprime, http://www.nsxprime.com/forum/showthread.php/196051-Bosch-cop-coils and then distributed by A.S.Motorsport

http://www.nsxcb.co.uk/showthread.php?14348-Ignition-upgrade-kit-Stronger-amp-faster-spark-A-S-Motorsport&highlight=a+s+motorsport+coil

[umran9]

replicating this, originally designed 'open source' on NSXprime, http://www.nsxprime.com/forum/showthread.php/196051-Bosch-cop-coils and then distributed by A.S.Motorsport

http://www.nsxcb.co.uk/showthread.php?14348-Ignition-upgrade-kit-Stronger-amp-faster-spark-A-S-Motorsport&highlight=a+s+motorsport+coil

Don't the Bosch Coils need to be machined etc so they can fit the Nsx?

[britlude]

Don't the Bosch Coils need to be machined etc so they can fit the Nsx?

as far as i can tell, the 'machining' is tweaking the rubber to fit in the cylinder sleeve..... the first pic on 'Operators' thread shows the difference, and he only mentions having a 'rubber grinder'... to anyone this side of the atlantic that equates to a belt sander

http://www.nsxprime.com/forum/attachment.php?attachmentid=134186&stc=1&d=1463927844

original thread text....
These coils dont need adapters. I have macined rubber seals to fit OEM covers . Perfect fit . Thats why we dont sell harnes without coils > Coils are special mede for NSX ie. rubber tweaked....

tho looking at it, they are thin seal rings, but we'll see once i get these to hand... i'm also lead to believe that the coil packs clip onto the hex of the sparkplug, giving a better/secondary earth path, so the top just has to make a snug seal


and it's annoying that the pic i chose previously doesn't show up in the thread, but shows up on mine because i looked at it on their site!!!! grrrr

[umran9]

Good Stuff il be keeping an eye on this thread...

[britlude]

receive this today from Lithuania!

https://farm5.staticflickr.com/4759/25878920208_4555111c6d_c.jpg (https://flic.kr/p/FqQens)WP_20180117_18_23_43_Pro (https://flic.kr/p/FqQens) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

https://farm5.staticflickr.com/4622/39718722052_0311108f23_c.jpg (https://flic.kr/p/23vNQhC)WP_20180117_18_24_02_Pro (https://flic.kr/p/23vNQhC) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

the one on the right (slightly lighter) is my possibly defective original, the one on the left is the second hand, slightly used 1998 honda Legend one!

it's on, and the car fires up... a good sign!!! ... I shall take it for a longer test run when i get a break from the major overhaul of the hotrod!... to be continued

[britlude]

early indications are positive, the engine smoother with the replacement ignitor.....

it'll get another long run out next weekend.....

[britlude]

so... the weekend is here, i get a break from re-engineering the hotrod to do some NSX investigation.....

the lithuanian ignitor was working ok, then came a stutter... so in went the USA ignitor..... that didn't cure it either, so the lithuanian one was put back in as it seems the best of the 3....

next port of call was to replace the coilpacks, as i have a set that was a deal on ebay a while back (£92 the set of 6!!).... being aftermarket they need a little fettle to fit with the coil covers, so a quick tweak and in they went...

i also rigged up the fuel pressure gauge where i could see it, and with Sarah doing the fuel pressure monitoring, off we went, the same route that had shown the problems previously.....

i'd narrowed it down to a 2000-2500prm misfire, on an incline (so increased load) but as soon as you got over 3000rpm it seemed fine pulling well and no misfire!!!!

we followed the same route, car already at working temp,Sarah calling out the fuel pressures......

36psi no load/overrun
42psi light load
50psi when the pump gets full power with the resistor shorted out

the pressures were stable and predictable throughout...

fingers crossed, the problem didn't re-occur during this drive, so maybe we've got there, but i'll keep an eye on it!

[britlude]

well, at the weekend we took the car down to canterbury, about 38 miles there, so i had a good run on the motorway, and fingers crossed it behaved itself, didn't miss a beat, hurrah!

the engine idle has been been getting a little higher over the last couple of weeks, and when we got back last night it was hunting between 1500-2000, so investigation needed......

the internet search puts the favorite as the cold idle air controller being at fault.... if it doesn't seal properly when the car is hot, then the air bleeding past it raises the revs. if sufficient revs are seen by the ecu, with no throttle, it decides you're obviously coasting for the engine revs to be high with no throttle input, so it cuts the injectors, no fuel, no revs, so the engine speed drops... once it reaches the idle level expected by the ecu it then re-fires the injectors and tries to control a stable idle..... but the bleeding air means the revs raise too far, and the cycle continues...... or something like that anyway!

first i removed the filter cover and the rubber connecting hose to the throttle body, just to check there was nothing holding the throttle butterfly open, and that the throttle cable was slack with no pedal depression, but that's all fine.

on the generic honda throttle body internet threads, the fast idle control and electronic idle control had separate filter-side ports feeding them, and the video examples showed simple fault finding by covering each port in turn to isolate each air valve circuit. unfortunately on my early JDM throttle body i only have one common port :( however covering that did stall the engine, so i know the main throttle butterfly has a good seal! it also shows there's no air leaks elsewhere!!! mines that early i don't even have the baseline throttle adjusting screw everyone else has!!!!

no throttle baseline adjusting screw above the butterfly
https://farm5.staticflickr.com/4651/40069779022_c65fc73586_c.jpg (https://flic.kr/p/243Q6i1)WP_20171230_12_30_18_Pro (https://flic.kr/p/243Q6i1) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

anyway, taking the endplate off the cold idle control valve, and starting the engine, i could raise the revs by depressing the valve plunger as expected, but couldn't seal it to confirm how much it was bleeding air in the hot/closed position. spraying carb cleaner onto the valve plunger did alter the engine speed, so there was some air getting thru......

so i unscrewed the valve seat, and removed the plunger to give it all a clean.....
dirty
https://farm5.staticflickr.com/4714/26227440378_3d8a34f0ca_c.jpg (https://flic.kr/p/FXCugU)WP_20180205_16_29_20_Pro (https://flic.kr/p/FXCugU) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

clean
https://farm5.staticflickr.com/4716/26227439428_bc47687599_c.jpg (https://flic.kr/p/FXCtZw)WP_20180205_16_31_29_Pro (https://flic.kr/p/FXCtZw) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

the actual seal is right at the base of the brass bit, where it's still brown, so it got a little more cleaning just to make sure! blowing thru the closed valve showed it pretty much sealed! i fitted a new o-ring on it too, as the one on it was like a solid strip of plastic!

clock fuse out and back in to reset the ecu, the car was started and let to sort itself out.... fingers crossed, it now idles a lot slower, 850-900 on the dash when hot... i just need it all to cool down so i can see what the water temp idle control valve decides the cold idle is, and adjust to suit!

right, now back to the hotrod......

[britlude]

another quick fiddle as it had all cooled down.... revs still seem a little high when i re-tried it.... re-checked cold fast idle valve... that seems closed with the carb cleaner test, so i'll have to back that off once i i try it properly cold!

took it around the block to warm it up, and when i returned it did have a little hunt so i disconnected the ecu controlled valve just to see what the actual baseline is, and it settled quite happily at 650rpm on the dash.... so the ecu is controlling the revs...

reconnected everything, and started up, it fired up at about 1800rpm then slowly dropped to 900... more monitoring!

[Kaz-kzukNA1]

Next time when the engine is cold, please start the engine and monitor the rpm after 10sec.
Should be around 1,500rpm.
If the fast idle valve is faulty, normally you would see really high fast idle rpm such as 2,500rpm.
It seems this is not the case with your NSX.

Once fully warmed up, please check the resistance of the TW sensor.

On our NSX, there are 3 coolant temperature related sensors.

The Rad Fan control sensor, Coolant temperature sender unit and the TW sensor.
Rad fan one is on the thermostat cover and it controls the on/off as well as mode of the radiator fan.

The sender unit is purely for the dash gauge temperature display/dial and it sits below/near the TH body.
It's the vertical body sticking out of the water passage.

The TW sensor is the one for ECU EFI control.
It's located on the front bank below the front VTEC spool valve.
The connector body is covered in black sleeve.
It's thermistor and when fully warmed up (about 83degC at idle rpm), it would be about 300ohm (200 – 400ohm).

There were several TW sensor failures reported in the past resulting in high idle rpm even after fully warmed up although it would be much higher than your case (900rpm).

By the way, the rpm gauge could be showing the wrong reading than the real state.

There is a small rpm signal terminal at the INJ resistor block.
If you can measure the frequency, it's 6cyl engine so 3 pulse per 360deg.
At 800rpm, it is 40Hz so you can compare it against the rpm/tacho gauge.
Target idle rpm for AT model in Neutral is bit lower than the MT and it's 750rpm so 37.5Hz.

Kaz

[britlude]

thanks once again for your input Kaz, much appreciated!

i did realise, after i'd logged off, that the 650rpm baseline with the ecu controlled air valve disconnected shows that particular valve isn't letting air through, and it IS the ecu lifting the revs.

starting up cold, the revs on the dash are 1650rpm. i'll have to wait until the weekend to see if the temp controlled valve is dropping, letting some air past when cold! after driving home from work and parking up, the revs are still about 1500rpm, front radiator getting warm..... letting it run on the drive the revs eventually, like 5 mins later, dropped to around 1000rpm....

i did investigate the water temp sender that the ecu uses, but they didn't make its position easy to access! you can see it, but getting to it is another matter!!! after almost burning my hand i gave up trying to get the cable connection clip off.... i have ordered a replacement anyway, and shall swap it in at the weekend when i have more time, light and a cold engine!!! no doubt with snow thrown in!

i've got to track down the rpm signal terminal at the INJ resistor block....... but its dark and cold out there now!!!

[Kaz-kzukNA1]

TW sensor is for EFI control so you can measure the resistance at the ECU connector.
For your NSX spec, it's located on the 22pin connector.
The VBu (Backup memory voltage) is also on the same connector so if you disconnect it, it will reset the ECU, same as removing the 7.5A CLOCK fuse.

Not required but to be on the safe side, just disconnect battery GND terminal, pull out 22pin ECU connector and measure the resistance between the terminal 'TW' and one of the 'SG (Sensor GND)'.

As your idle rpm was 1,500 – 2,000rpm at one point but now it seems to be much better at 900rpm, very unlikely to be the TW sensor but at least, by checking it, you can eliminate one possibility.




The rpm measuring port is the tiny 2pin connector held by a small rubber cap near the INJ resistor.
The bracket is actually on the Eng bay cooling fan unit.
I thought about taking photo of my NSX but I already removed the cooling fan long time ago so not relevant and I believe your NSX is AT spec so you should still have the cooling fan in the eng bay.
Although it's tiny 2pin connector, there is only one wire used.


Kaz


https://lh3.googleusercontent.com/iLP-npf133JX9L_0B9AZsC1Uzctsr-8BuJEI48WUpeoNh_5nsAnKk991FIPhW74umW0acdbQNPfnyrtC 4QsUUvw9bX_X4dIak6GcOeubLiIrrRxsIYcbVB6-dJrdWALt8gmkY3wv_sWx0iJdnpaJfiERGQeQyq-IRvZrxAweFxmVBHIcVPKUgpL5S0sTltOpAq6OMXhw5zleDWWrc iwuBddg7TzSx3xfwFRR_EjVu_eNaEv23yTzKN_E2n8hGFWuh4T aDweXiX4XLDH-_oZqBNYFeabtXC0rOyvyZI25a1ol3dmTTrN25EierqB2ZGjDYf tIdEpPp8mCnBvElEIzMq8pZQ59VhC0r8rWiot00zZvsugrm7Nm HFO9tXfmuo0_mfpfWQfbMaOlcXN6QS08U4jYHCPlkEM1i5npzK yPe4OeG7MAgrXGuTpIZM8afHby7CPkgHuHkSNOhmudKo4If0Fj dLcMHilh8yqVDuTkEkAoWakCxzDuysGJnZv-N-rfXyVOZIJtGe15zCVi-jDjeJodrao20anGudetvB-Xw4KfQAmkTwbLDmjkVqm-9aPBmTRoZlca3WBcsq2HjomR-lMMJJ0OmFeNEfI-LGsb=w1080-h810-no

[Kaz-kzukNA1]

https://lh3.googleusercontent.com/y6LEUmq43r3SRG3yN84vSqTdkil_6kTPdg_MoFFTgI7V7XHuDc f4EFy80Kp0vkmFHxlC0FFP3CuR1ajVWbtDxAAoj27rnEgpuVAy ZA3nefge_swEhY6Yzz1Clt6p3lrRcQRWisgXrsuzuqoVvI6cfn gDcEGng2r5dU2mwu4LrKCB2PCCZLt_NQF1WZz_CGhWTl9HrGMg 3ZwCVMq0Wcnn8EmQOcI3LAA5LwEb8Fh9eCrMwEzkhGmO9zDa1k y9qO3xDRSWDU6PrdqNJ2js-A_mDKTFmS0RjwncBNhQpmTecQXlr1Ug3nv6deqTAItu6mYGHZs-m31sSE3_xndIU6TVSeMWytwYOWh8rL7XSl903mP8xnqDRWNXct moEDi-GGJWKb-40Rtp77TLO2nnzraS6rm4k_8fuW4wEukXfw9RZT8CQF4hzSKLl k9L7ZJb_7TEQLb6Softc3O1vpM5txDpiEo9yIV5BCXz-Q6nvJZcyq5iHb3D5oaZC-3EtSAd8JPI0IugbrfhPceE8aHxUlV-esnTKkrRe9WJhPkJF3cx2d3O6P0ybtkfivbv62Bkeh3RyGP54G F8I3l50eEYGVdk4yo-x57s8X436yUFNyhU=w1080-h608-no

https://lh3.googleusercontent.com/PvLlZ5cdKDvtrFeLbObcFxtHgAIkgRmxELwPQzJoakgHEINQrl J3TsxkV0HFcjvs6Ih5YAn2NpNiQP-11KbwN746oPRQYRqYBNTCce6bfHasafRQFuIeoftgFob84jjja MTIYyD3ie7FUoDVS28OdbYYj1B0RjgWnRNzZfYkGgxank4cq2r V-WKjRUU_jGPV23adEsXRq16hbGlYfM8odNB5b-57RacuiDt0TDyDczKJ5WZmwFoF6Jcg5LT98r1nK66Y0H2goOtI 7Enqwf_d5kgzxkwyx401ioFDXw0XK9IwyLC5hFaHxtgB0fxmM3 LbgnsDESnZvRyMw4V77PnPCAMnZrodiyYyJ1iU1Krs6pV-_T3LpV8WF0u5GVQgdazP73bGfxlSvE6xLgmxuohINtIgOz80l3 YoC8McTfT5Ff3HqVtWj8lde51LCH-w3omiaPGib6x4nDzWwioJsO3WDUa9u32xH5KYspzn0Pn_vZQZs UANEwK0rJYX43SIegZx5ecQYcZZ-pA5-pKv3brVN2Qft8QgRCaahuIvqD21qFXetdUMYsVF5k6XWdBVoET 5yy6MuH-G6mIMSxf4vhQ6YelHlPxmfGAX-EI62JBv=w1080-h608-no

https://lh3.googleusercontent.com/4S2gW2Z0IAbGCt3emTvPmUdly_2YNXF8EjZwKw00ZNYgHdnowO RUsCsQR1HNhyGNG4Moo4awJAyiIN27cS2AW44PaYCUm0fSX7OK AS6PmfFVa0sUJdMZR8FEezfMvtfwbntpKth4TKhPzR_zI2wz4w e7LTk3MmRg4yzZ6OlEHIdyGRW3O0RK0x9qrZlG4Rv040UCZMl6 aFR1iocxXtCBW8s6X_omBn9z7ZnE1w2p8_72k4-snKNciMhuemqRaXQqocRo1vHw8cWtuYBIx451qg_fNXZXbPArn chwdHMr3hjvRuaFewAO0IelvRhUafCCXiGth8Z8ABcgk3xWPS3 cCcU2I43FMCh_aoKO6WXo7Zt4_KbqW1F0vb5YJimFtxUKm2S3Y 1dq-SyTBVfnycSQvj-eZSyIhfCZkd4_azt28C3_fPF4F516H5SNla_dIO9l2C4L3GqwV e2GsiXl2mL-O5MpKHJx10C89Z5EqzQCjFWZjxjP047Wqvt0eQ4fN8vXHoFwYj B5Vh9tNGv6YJsrr363DiTVAtDdrd4sY3qIij7C1S-_75WxiYZBiSWAgCntFeuvh-Kgv_iPLXT4ZBDrmJLQyGS0RwfTNSZVi8Pr=w1080-h608-no
For the record..... TW sensor reading at the ECU connector.



Mine is non-DBW JDM so should be the same terminal position for your spec as well.
Please note that this could be at different pin out for other NSX spec so please check first.


Kaz

[britlude]

once again going above and beyond! thanks Kaz..... i shall investigate at the weekend, busy with the hotrod and S800... still!!!!

[britlude]

the idle was still fluctuating a bit, so i spent a little time out in the cold swapping in a new water temp sensor, for the £7 it cost, it's a cheap option!!! anyway, half an hour later the new sensor was in, coolant levels restored and engine warming up....
https://farm5.staticflickr.com/4701/39477560914_1086fc8191_c.jpg (https://flic.kr/p/239uPtY)WP_20180210_10_08_31_Pro (https://flic.kr/p/239uPtY) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

the added bonus is the new sensor was the same orientation as the old, so no faffing around trying to turn the connector to the right way round and never being able to easily get to the release tang again!!!

car up to temp, radiator hot, the revs seemed better, and finding the secret rpm terminal i have this.....
https://farm5.staticflickr.com/4653/28409021989_eee12a41a5_c.jpg (https://flic.kr/p/KhpEtX)WP_20180210_10_49_18_Pro (https://flic.kr/p/KhpEtX) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

with the magic of maths, multiply the Hz by 20 to get the rpm..... gives approx 875rpm, so the rev counter not a mile out! a bit high with the auto's target of 750, but pretty much where its usually at!!