Gizzard Puke & throttle cable tension

[Nick Graves]

I've just carried out one of my favourite tuning measures; cleaned the throttle butterfly & venturi with choke cleaner and removed a huuuuuge amount of play from what there is of a DBW throttle cable. A tiny spot of silicone lubricant spray on the throttle cam (cable's plastic sheath, actually) too, for extra smoothness.

What a difference! I'd swear I've found 10 BHP (although that's probably an illusion - but it's no longer only as fast as my S2000!) the whole thing is much smoother on/off the throttle, seems to run sweeter and of course, the extra accuracy has massively improved the handling such that drifts are a beautiful as they ought to be and it all comes together far more.

I thought I could feel the butterfly sticking off idle and it was 'graunchy' across the range of travel. Quite how you do that with a DBW, I dunno, but someone ought to tell other manufacturers. The feel truly is superb now.

Honestly, it's a simple job and well worth the effort if yours hasn't been done in a while.

[Thunder]

I made the same thing, I cleaned the air tubing and the butterfly with grease-remover and cleaning driving and lubricated the cables with grease lithium, the result is fantastic, with what cleaned your air tubing and the butterfly?

[AR]

Probably just crud accumulated over time.

[Nick Graves]

I made the same thing, I cleaned the air tubing and the butterfly with grease-remover and cleaning driving and lubricated the cables with grease lithium, the result is fantastic, with what cleaned your air tubing and the butterfly?

Avec du:

http://www.carcare-online.com/images/CARB%20&%20CHOKE.jpg

ou quelque chose similaire.

[WhyOne?]

I've just carried out one of my favourite tuning measures; cleaned the throttle butterfly & venturi with choke cleaner and removed a huuuuuge amount of play from what there is of a DBW throttle cable. A tiny spot of silicone lubricant spray on the throttle cam (cable's plastic sheath, actually) too, for extra smoothness.

.................

Honestly, it's a simple job and well worth the effort if yours hasn't been done in a while.

Is it possible, in idiot-laymans terms, to explain precisely what 'effort' is required please Nick?

[Thunder]

Avec du:

http://www.carcare-online.com/images/CARB%20&%20CHOKE.jpg

ou quelque chose similaire.


Thank you :-)

[Nick Graves]

Is it possible, in idiot-laymans terms, to explain precisely what 'effort' is required please Nick?

Well, I can do it!

There's a black box on the RHS damper turret. A 10mm bolt back & front hold the cover on. Remove it & you'll find the throttle cam on a rheostat. The throttle cable is secured by 12mm locking nuts. On no account spanner the outer one as there's a boss underneath the lock it from turning. Crack the inner one & thumb it to the end of the thread. Pull the cable sheath until the cable's almost taut, spin the outer nut down to the boss & then re-position the cable & lock up the inner nut. The cable oughtn't be tight like a guitar string; there ought to be a little play before the cam starts to turn. The cable gets shorter in the winter...

A little Holts Silicone & rubber lubricant (ot interior dressing!) on the plastic cable sheath (if you open the cam by hand, you can pull the cable off it) ought to help too. Reassemble.

Accessing the throttle body requires removal of the accordion; slacken the two jubilee rings and the 10mm nut which attaches the breather pipe to the TB. You can remove the air box cover, but it's not absolutely necessary. I just squeezed the accordion down & forward so I could see the brass butterfly. Place a cloth underneath to soak spillages.

Do not follow the destructions on the spray can: running the engine seems dangerous. Spray a little round the butterfly & let it soak in. Use a plastic handle to push the 'fly open at the bottom & spray the other side & where it seats. You need to wipe off the carbon deposits from those ridges, using a cloth. Small hands or a gyneacology qualification probably helps here. Giving the stuff time to work and to evaporate is the key.

You don't want to use the whole can, or you will hydrolock the engine. So don't go nuts.

Once you're happy the 'fly is moving easily, re-assemble carefully & give it a little vapourisation time before attempting to start.

You will have flooded the engine, so it will need a long crank before it splutters into life & settles down.

It ought to drive like a new car now.

I'm convinced doing it regularly cleans the burnt oil/combustion crud from the plenum butterflies and the backs of the inlet valves too, which is why it seems to run sweeter.

If it's too daunting, you can always bring it 'round here!

EDIT: be careful with tins of choke cleaner with a push-in type extension pipe. I once shot the extension down the Prelude's gizzard and had to dismantle it to fish the pipe out of an inlet port! It's got variable-length tract butterflies & stuff just like the NSX...

[Kaz-kzukNA1]

If you are carrying out this process, as Nick mentioned, please remember to leave some slack/play in the throttle cable for both DBW and non-DBW model. It is important from the heat, vibration, idle rpm, etc point of view.

On DBW model, there is a specific distance mentioned on the manual on how to set the lock nut for the throttle cable and if you go too far, it will affect the idle control.

It is a good idea to clean the throttle butterfly and surrounding area once a year. I think the TH butterfly on Nick’s car was showing the typical sticky butterfly on most of the NSX. By the way, you won’t gain any power unfortunately. There has been extensive study carried out on the throttle body diameter - power by the manufacture/NSX specialist in Japan and you just recovered the throttle response…

For DBW model, the cleaning process is quite simple but please note that on some cases, you may need to adjust the idle rpm depending on what was done in the past before the cleaning process. This will require specific procedure to be followed in order to achieve the correct idle rpm.
On DBW model, there is no EACV or idle air port on the TH body and we are relying on purely for the tiny air gap between the TH body and the butterfly controlled by the stepping motor.

For non-DBW model, the key for the cleaning process is to target the cleaner to the idle air port, EACV and Fast Idle valve. If you look into the TH body from the air box side, you will see small hole at about 11 o’clock position. Addition to the Nick’s procedure, please shoot some cleaner in there. For this reason, you will need to keep running the engine during this procedure.

For any of the above process, please never use the brake cleaner.
You will be carrying out the process on warm/hot engine parts and some of the brake cleaners are flammable as well as it may produce hazardous gas.

Happy cleaning.

Regards,
Kaz

[Nick Graves]

Just to clarify Kaz' point:

Cleaning the TB improved the handling(!)

The NSX has a very short-travel throttle pedal and there was probably 1/2" or more lost motion on mine and I'm sure I wasn't getting WOT at full throttle. Hence the 10 BHP guesstimate.

[Thunder]

To clean the tube butterfly, I used a powerful grease-remover (degreasing before painting), then, I polished with of Belgom Alu, the result is very good, at the same time, I replaced the spark plugs and to clean the pads coil, lubricated all the cables with liquid grease with lithium, the idle was stabilized after ECU reset

[Papalazarou]

Sounds like a great idea and you guys have obviously acheived some brilliant results. But! I can't believe you'd use one of the cheapest nastiest carb cleaners on the market!
I'm sure it's probably ok, but some cheap carb cleaner take coatings off throttle bodies.



Cheers,



James.

[WhyOne?]

Genius Nick, genius!

I spent a happy half hour attending to my DBW throttle cable as instructed. As with your car, I found what I perceived to be a huge amount of slack cable. This is now adjusted (still leaving some slack) and the cable / plastic sheath have had a quick dose of silicon lubricant.

The difference is astounding - the slight 'stickiness' apparent on the throttle pedal since I took delivery of the car (4 years ago!!!) has gone, and the application of throttle seems so much more progressive / smooth / immediate (and as you suggest Nick...the car feels faster!)

Very chuffed!

I will look at throttling my butterfly one evening this week - what cleaner would you suggest James?

Many thanks for taking the time to detail these procedures Nick.

:)

[nakamichi]

"There's a black box on the RHS damper turret"

Excuse my ignorance but is that front or rear damper.?
I looked at the one at the front marked cruise control,is that the one you are referring to?
cheers
Tony

[WhyOne?]

"There's a black box on the RHS damper turret"

Excuse my ignorance but is that front or rear damper.?


Front compartment.

[nakamichi]

Front compartment.

cheers
thought so but was just checking.
There does seem to be a lot of play in the cable but adjusting the locking nuts doesn't seem to make much difference.
How much "slack" have others had to take up?
I don't want to adjust it too much in case I adversely affect something.

[WhyOne?]

How much "slack" have others had to take up?


Hard to be objective about this, but I guess I moved the locking nuts ~2-3mm towards the throttle cam/ rheostat.

[markc]

Any pics of what to adjust chaps?

The last other NSX I drove, a 2003 car, had a very long travel and rather "soggy" throttle compared to my car.

I just put it down to either my ECU being different (JDM) or general changes in model year but from what you've described it could be this cable adjustment?

Cheers

Mark

[WhyOne?]

Any pics of what to adjust chaps?


I didn't take any pictures, but if time permits I will open the box up this ev. & take a quick snap to post here.

Being technically inept, I was a little apprehensive doing this, but armed with Nick's instructions all becomes clear once you are 'inside the box'.

[Kaz-kzukNA1]

"There's a black box on the RHS damper turret"

Excuse my ignorance but is that front or rear damper.?
I looked at the one at the front marked cruise control,is that the one you are referring to?
cheers
Tony

Front compartment.

cheers
thought so but was just checking.
There does seem to be a lot of play in the cable but adjusting the locking nuts doesn't seem to make much difference.
How much "slack" have others had to take up?
I don't want to adjust it too much in case I adversely affect something.
Hi, Tony.

After reading these posts, I’m not sure which side (front compartment or engine bay) of the car that you are working on at the moment to adjust the cable play but if your NSX is 92 model (as in your signature) and unless you have modified your system to DBW, I would recommend not to touch the cable inside ‘the black box on the Front RHS damper’.

Your NSX is non-DBW model and differernt from the ones as Nick, WhyOne or Mark. They have DBW model.

As in your post, it’s for the ‘cruise control’.
If you are already aware of this and working on the TH cable play inside the engine bay, then please ignore this post.

If you have accidentally touched the cruise control cable on your non-DBW model, please refer to the attached file ‘CruConNonDBW.pdf’ to put it back to where it should be. On non-DBW model, this cruise control cable is connected to your throttle pedal so please be careful.
7111

For those with DBW model, I’ll also attach the THcableDBW.pdf showing the factory setup for TH wire adjustment as a reference.
7110

Kaz

[nakamichi]

pictures



http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=7114&stc=1&d=1277120051

http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=7115&stc=1&d=1277120110

[nakamichi]

[QUOTE=Kaz-kzukNA1;73528]Hi, Tony.

After reading these posts, I’m not sure which side (front compartment or engine bay) of the car that you are working on at the moment to adjust the cable play but if your NSX is 92 model (as in your signature) and unless you have modified your system to DBW, I would recommend not to touch the cable inside ‘the black box on the Front RHS damper’.

cheers Kaz
I have left it as it was as I don't like messing with things unless I know what I am doing.

[Nick Graves]

That DBW box is slightly different inside from the NA2s.

But the adjuster's the same - all you should be doing is 'shortening' your throttle cable and not affecting anything else. Just like the brakes on your bicycle.

If it's any help, the Prelude has a vacuum cruise piggybacked onto the throttle cable. The throttle may be adjusted (on the throttle body itself) in exactly the way described. I also took a little play out of the cruise cable (on the vacuum servo, IIRC) and that took a lot of jerkiness out of its operation too! I should imagine an early NSX isn't vastly different, but Kaz should know better.

[Nick Graves]

Genius Nick, genius!

I spent a happy half hour attending to my DBW throttle cable as instructed. As with your car, I found what I perceived to be a huge amount of slack cable. This is now adjusted (still leaving some slack) and the cable / plastic sheath have had a quick dose of silicon lubricant.

The difference is astounding - the slight 'stickiness' apparent on the throttle pedal since I took delivery of the car (4 years ago!!!) has gone, and the application of throttle seems so much more progressive / smooth / immediate (and as you suggest Nick...the car feels faster!)

Very chuffed!

I will look at throttling my butterfly one evening this week - what cleaner would you suggest James?

Many thanks for taking the time to detail these procedures Nick.

:)

Pleased it's not just my imagination! No problemo - it's exactly what these forums are about.

James,

I used Comma cleaner in fact, but that was the only .jpg I could find to explain it to Thunder.

IIRC, it was the Wynn's where I shot my bolt down the Prelude's gizzard, so I wouldn't particularly recommend that one for the crap design.

EDIT: Bollocks! Do a search on another day and:

http://www.camskill.co.uk/smsimg/79/55684-58960-main-comma_carb_clean_aerosol-79.jpg

[NSXGB]

Good shout Nick. Something I had overlooked.
Unfortunately I only gained 5bhp but well worth the 2 mins it took to do. :)

[WhyOne?]

Any pics of what to adjust chaps?



Your wish is my command!

The first picture shows the (somewhat grubby) front compartment of my 2001 Drive by Wire car, with the 'black box' in question sitting in the centre upper left of the photo.

The following 2 pictures show the cable / rheostat assembly (and the two 12mm nuts Nick describes which facilitate adjusting cable tension, bottom right of 3rd picture - make sure you loosen the inner nut - the outer one has a boss locking it in place) which live inside the box.

[Kaz-kzukNA1]

For your reference ....

7120
Inside the Front compartment, if you can see black cable coming out of the 'Black Box' and surrounding the brake fluid reservoir, you have the DBW model and you can follow the process described in Nick's post.

7121
However, if you don't have black cable surrounding the reservoir, please don't touch the adjuster inside the 'Black Box'. It's for the Cruise Control and although there is a safety mechanism such as clutch and actuator inside, you could directly pull the TH pedal if you don't follow the factory setup. You don't want unexpected sudden acceleration.


As an extra info, you can distinguish the DBW/non-DBW from the engine bay.

At the right side of the engine, you will see Fuel Line coming out of the Fuel Filter (black round shape metal box) located behind the angled chassis frame.

7124
For DBW model, you won't see the single black cable out of the firewall running in parallel with the Fuel Line.

7125
For non-DBW model, you will see this black cable and this is the TH cable running all the way from the front, ie., the TH pedal.
For non-DBW model, if you need adjustment, it will be done at the adjuster next to the TH body inside the engine bay and not at the Front 'Black Box'.

Kaz

[Papalazarou]

Pleased it's not just my imagination! No problemo - it's exactly what these forums are about.

James,

I used Comma cleaner in fact, but that was the only .jpg I could find to explain it to Thunder.

IIRC, it was the Wynn's where I shot my bolt down the Prelude's gizzard, so I wouldn't particularly recommend that one for the crap design.

EDIT: Bollocks! Do a search on another day and:

http://www.camskill.co.uk/smsimg/79/55684-58960-main-comma_carb_clean_aerosol-79.jpg


Wynn's, forte or, if you have to Wurth are all pretty good. Comma, autocare etc are all budget, but if it works it works I guess.


Cheers,


James.

P.s, "shot my bolt?"

[Nick Graves]

Old expression from the days when rifles weren't very reliable. Once you've done that, you've had it!

Seemed appropriate for that poxy can of Wynn's, where the flexi tube is(n't) an interference fit into the cap!

[Sudesh]

Ive always used this and it works just fine.

http://2.bp.blogspot.com/_Zl3HQgWfsPc/St8zguZme7I/AAAAAAAAD3A/ORO6n5Qhbow/s320/stp93.gif

[Papalazarou]

Old expression from the days when rifles weren't very reliable. Once you've done that, you've had it!

Seemed appropriate for that poxy can of Wynn's, where the flexi tube is(n't) an interference fit into the cap!

Ok, sounds like driver error. I sell perhaps 20-30 cases of this a month and never had this issue, either using or supplying. The flexy nozzle 'is' interference fit, you've just got to push hard.


Cheers,


James.

[indi pearl]

Many thanks' for info Nick. The Godess had been getting a little "slack" of late which I had put down to her increasing years! However a trip to my surgery and a tightening of her internals (a good 3/4mm) has returned her to full on youthfull vitality.

[Nick Graves]

Ok, sounds like driver error. I sell perhaps 20-30 cases of this a month and never had this issue, either using or supplying. The flexy nozzle 'is' interference fit, you've just got to push hard.


Cheers,


James.

:D

You should tell 'em to make the attachment more twuntproof then! Honda owners expect Japanese levels of precision.

[Martin]

Are any of you going to Gaydon Supercar Sunday, and if so, could you do this to my car?! :)

I would be afraid of touching it in case I blow it up :)

Cheers
Martin