My NSX won't start

[rocco1]

Hi guys,after two weeks, I decided to take my car out for a run... would not start. 10 mins later, tried again & it fired up. Just before it fired up, I could hear a faint noise and it started. No problems, drove 10 miles, parked up for 1 hour and guess what?? Yep, would not start and still unable to start. I think I have previously mentioned this and I think you mentioned a relay? Where is the relay located? Where can I purchase one? How much does it cost and is it a diy job? Many thanks, Rocco

[Sudesh]

Hi Rocco,

Relay is located behind the long trim piece that runs along the rear cabin window. Yes it is a very easy DIY job. If buying new then your local dealer can supply it, otherwise try Andy at VTEC.

Price wise I think its around £100 or £110 new.





Hi guys,after two weeks, I decided to take my car out for a run... would not start. 10 mins later, tried again & it fired up. Just before it fired up, I could hear a faint noise and it started. No problems, drove 10 miles, parked up for 1 hour and guess what?? Yep, would not start and still unable to start. I think I have previously mentioned this and I think you mentioned a relay? Where is the relay located? Where can I purchase one? How much does it cost and is it a diy job? Many thanks, Rocco

[rocco1]

Hi Rocco,

Relay is located behind the long trim piece that runs along the rear cabin window. Yes it is a very easy DIY job. If buying new then your local dealer can supply it, otherwise try Andy at VTEC.

Price wise I think its around £100 or £110 new.
Thanks Sudesh! do you think this is the problem,as i can't hear the faint noise before i turn turn the ignition over.Anyway the little drive that i manage to have made me realise how special these cars are, not only did i get the looks,but its how it performes,wow what a car.Ive seen a house which i am buying for my doughter which has a very large garage,maybe ive found some room to keep my NSX.

[rocco1]

How do i find Andy Vtech?

[Sudesh]

Hi,

Cant make the assumption that it is the main relay without testing myself, but as it's a fairly common problem and well documented it certainly sounds like it. Kaz is the expert there as I havent [touch wood] run into this prolem yet with my own car or customers cars.

But as Kaz mentioned in the past, it's really worth having a new one installed and the old one re-soldered and kept in the glove box as the back up.

Andy can be PM's here: http://www.nsxcb.co.uk/testvb/forumdisplay.php?f=38

[rocco1]

thanks again,how will i know which relay to replace,is it a certain colour?

[Sudesh]

thanks again,how will i know which relay to replace,is it a certain colour?

The relay is black and if your order a new one, then visually you will be able to pair it up no problem. For your car I believe the part number is 39400-SL0-A01, PRICE £109.63 from Honda

[rocco1]

Where elese can you find this sort of info at this time,many thanks Sudesh

[Dragonlady]

Hi Rocco,
It would be really worth trying to get your car booked in to see Kaz for a health check if you are not to far away, or if you can to at least diagnose the problem.
We did it and we have never known anybody to be so thorough and handle your car with such care.

Regards Ian

[rocco1]

Hi Rocco,
It would be really worth trying to get your car booked in to see Kaz for a health check if you are not to far away, or if you can to at least diagnose the problem.
We did it and we have never known anybody to be so thorough and handle your car with such care.

Regards Ian
Thans for the advice,where is Kaz located?

[Kaz-kzukNA1]

Hi, rocco1.

Seems like you missed the answer from other members to your previous thread on the same issue.
For your reference, my answer quoted below.

Hi, rocco1.

When you say ‘failed to start’, do you mean that you can crank the engine but not a single bang/fire at the engine?

If that was the case, then, I would look at the Main Relay first.

When you first turn the IGN switch to ‘ON’ position where you see all the lights showing up on the dash, the main relay is triggered and prime the fuel pump for 2sec. For this reason, I normally wait for about 2sec in ‘ON’ position before start cranking the engine just to listen to the sound of fuel pump. It’s a very faint hissing sound.

If you don’t hear this, then it is very likely that the main relay is faulty.

From the past experience, most of the owners failed to start when the car was still hot and once it cooled down, it started up without any issues.

Initially, the owners experienced some difficulty on re-starting the engine under hot condition but because the issue was intermittent, the issue was left until it really started to cause headache to the owner.

As you say it is 2003 reg, I presume it was manufactured around that time and thus, your NSX is DBW model.

For this, you need the DBW version of Main Relay.

Parts No. 39400-SL0-A01.

HUK will charge you about GBP110 inc.VAT for this but if you can get in touch with Andy at Vtecdirect, he should be able to get it cheaper. I have three but all of them are for other owners ....

You can replace it quite easily. Procedure is in post #165 onwards from the following link;

http://www.nsxcb.co.uk/testvb/showthread.php?t=6286&page=17



On the other hand, if you managed to fire up the engine but it died straight away when you released the IGN key from ‘START’ position, then I’ll look into the key cylinder contacts.

Again, some info in post #149 onwards from the following link;

http://www.nsxcb.co.uk/testvb/showthread.php?t=6286&highlight=cylinder&page=15

There are other things to check but I’ll start with the main relay first.

Regards,
Kaz

It would be easier to browse through my 'NSX Health Check Service' thread using 'Autopagerize' feature but in case you are not familiar with it, I'll cut and paste the DIY procedure for you in the following posts.

I'm based in Bucks. Please send me an email using 'send email' option by clicking on my user name 'Kaz-kzukNA1' if you are interested.


Regards,
Kaz

[Kaz-kzukNA1]

Hi, rocco1.
As your NSX is DBW model, your Main Relay is actually behind your right shoulder when sitting at the RHD driver's seat.

So, please also follow the extra procedure in the later post as well.

Cut and Pasted from my old post..........

+++++++++++++++++++++++++++++++++++++++
Back to the Yellow Targa NSX....

4. Main Relay

All of the owners who took my Main Relay service will have their original parts re-soldered so that it can be used for emergency spare for other owners.

I received several requests regarding how to replace the Main Relay so would like to share this info with you.
When the Main Relay fails, you can still crank the engine with the starter but there will be neither fuel nor spark and thus, the engine won’t fire up.

Depending on whether your NSX is equipped with DBW or not, the location of the Main Relay is different. Don’t worry even if you don’t understand the word ‘Drive By Wire – DBW’ model. The first interior panel that you need to remove is the same for both DBW and Non-DBW model.

http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6546&thumb=1&d=1265756776 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6546&d=1265756776)
The Main Relays for DBW and Non-DBW model. Although the number on the case is different (0101 vs 0152), the internal circuit board and the parts are the same. The bracket is different between the two. Also, on the relay inside, you can see the Year number on it. The internal relay was upgraded during early 90’s. Originally, it had coiled spring inside the relay module but later it was replaced with the spring plate.

http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6547&thumb=1&d=1265756776 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6547&d=1265756776)
When you sit on the right side seat, the Main Relay on Non-DBW model is located just behind your Left shoulder. For DBW model, it is behind your Right shoulder and thus, you will need to remove extra interior panel.

http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6548&thumb=1&d=1265756776 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6548&d=1265756776)
First, you need to remove the Rear Upper Trim. There are three clips at the top and one sharp needle like pin located at the left top side of the trim. There are several metal hooks at the bottom. Using both hands, first push down the top side of the trim and then pull it gently towards your body and lift it up to release the hook. The upper trim will come off.

http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6549&thumb=1&d=1265756861 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6549&d=1265756861)
Now look for a small black box behind the left shoulder of the right side seat with the label as ‘RELAY ASSY, MAIN RZ-0101’ on it.
It is next to the big silver box (EFI ECU).

If you can’t find it, your NSX is DBW model and requires extra panel to be removed.

If you found the Main Relay, you can replace it with new one by removing just one fixing bolt on the bracket and two connectors at the bottom. You may struggle to access the connectors but if you remove the fixing bolt, it will provide you with extra space allowing you to access the connectors.

[Kaz-kzukNA1]

On DBW model, you need the following extra procedures.

http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6551&thumb=1&d=1265757533 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6551&d=1265757533) http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6552&thumb=1&d=1265757533 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6552&d=1265757533)
Remove the Engine Hatch Opener by gently removing the spring behind the lever. After removing the spring, just insert it back on the lever to avoid loosing it and you can just push in the lever against the shaft during the re-assembly process.

http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6553&thumb=1&d=1265757533 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6553&d=1265757533) http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6554&thumb=1&d=1265757533 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6554&d=1265757533)
Pull out the Fuel Filler Door Opener and lift up the Side Sill Pad.
Remove the Door Trim and ...

[Kaz-kzukNA1]

http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6555&thumb=1&d=1265757548 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6555&d=1265757548)
...... then remove three screws to lift up the Right Rear Side Trim.

http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6556&thumb=1&d=1265757791 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6556&d=1265757791)
The Main Relay on DBW is located just behind there. Unfortunately, the case with the white text is facing rearwards so you won’t be able to see it. Please refer to the photo.


http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6557&thumb=1&d=1265757791 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6557&d=1265757791) http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6558&thumb=1&d=1265757791 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6558&d=1265757791)
Remove the bolt and the cable mount and ......

[Kaz-kzukNA1]

http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6559&thumb=1&d=1265757791 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6559&d=1265757791)
......... then the two connectors.

http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6560&thumb=1&d=1265757801 (http://www.nsxcb.co.uk/testvb/attachment.php?attachmentid=6560&d=1265757801)
Replace it with the new one. I always put the Month/Year info on the bracket for the future reference.

Put back the interior panels in reverse order and start the engine for testing.

If you want, re-solder the original Main Relay for emergency spare and again, write down the re-soldering Month/Year info on the bracket.

Job done.


Regards,
Kaz

[gumball]

Wow Kaz, your an NSX mending Machine!
I guess you don't follow LeMans then?

[WhyOne?]

I can vouch for Kaz's excellent instructions.

I am by no means technically minded, but with Kaz's pictures and explainations I managed to both replace my old Main Relay with a new one and (astonishingly for me!) bring the old Main Relay back to life with a soldering iron!

[rocco1]

Thanks for the advice, took me ten mins to get to, seems like someones been here before.

When you turn the key, you can here the relay click, is this the symptoms of a faulty relay? I can't here the pump prime. I've opend the relay but can't see any broken contacts

Thanks,
Rocco

P.s kaz, what part of the country you based in

[Hagasan]

Thanks for the advice, took me ten mins to get to, seems like someones been here before.

When you turn the key, you can here the relay click, is this the symptoms of a faulty relay? I can't here the pump prime. I've opend the relay but can't see any broken contacts

Thanks,
Rocco

P.s kaz, what part of the country you based in


It's in his posts, post #11.....He say's he's based in Bucks. That's Buckinghamshire.

Is this bad Karma as your car knew you were thinking of selling it!?!?;)

[rocco1]

:rolleyes: It's in his posts, post #11.....He say's he's based in Bucks. That's Buckinghamshire. He's in the Milton Keynes area..

Is this bad Karma as your car knew you were thinking of selling it!?!?;)
Will try to find his post#11.By the way it seems like she's spat her dummy out and stamping her feet! lol

[rocco1]

Hagasan how do i find post #11? been trying but my skills at using a pc are not very good.

[WhyOne?]

Top right hand corner of each post, in the blue 'strip', is its number (so, for example, this will be post #22)

:)

[rocco1]

Top right hand corner of each post, in the blue 'strip', is its number (so, for example, this will be post #22)

:)
Thanks mate,i think ive found the thread.