Failed to start!

[rocco1]

Hello all.just wondering what was the cause of my car not starting?I have a NSX 2003 reg,went for a run yesterday covered 100 miles or so,then parked it up to enjoy the view(Anglesark Rivington) after a 5mins jumped back into the car and it would not fire up! Felt very embaressed,the car just would not fire up.Anyway i called the AA and by the time i explained where i was and the AA trying to locate me on there systemit took another 10 mins.So whilest waiting for the AA to turn up i had another go again to start up the car and it fired up! Anyone had this experience? Been fine since,(maybe the sun got to its head,lol)

[WhyOne?]

Main Relay playing up?

Symptoms sound fairly typical.

You probably didn't notice, but when you turned the key to position 1, did you hear the fuel pump priming for a second or 3? If the main relay is playing up (as it did on my car a few months ago) this doesn't happen and is a good tell-tail.

The Main Relay does commonly fail on NSX's - it is a relatively easy (and mercifully cheap - ~£100 from Honda UK, much cheaper from the US) part to replace yourself. More info. here:

http://www.nsxcb.co.uk/testvb/showthread.php?t=7426

[Hagasan]

I have similar experiences occasionally......but the main relay has been replaced. I wiggle the key a little (the ignition switches can go faulty but respond to opening and cleaning up) and as it's turning dab the throttle and it fires up with a slight rise in revs. Always starts when cold ok but get this after a run and a quickish restart. Could be fuel vacuum related or maybe even a sensor but I just live with it as the car behaves ok in all other respects and I know how to deal with it..

[simonprelude]

Another vote for main relay here, however I would ask how many keys you have on your bunch as too much weight on the barrel has been known to cause similar issues.

I always keep car keys on their own to stop that problem.

[Kaz-kzukNA1]

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

[rocco1]

thank you all for youre response,car is running fine at the moment,will go for run again and see what happens,many thanks again.

[amo]

ingition switch for my vote fiddle with the key and it starts another comon fauilt

thx amo

[NSX 2000]

thank you all for youre response,car is running fine at the moment,will go for run again and see what happens,many thanks again.

Hi rocco, IIRC you have made a couple of changes (mods), were any of these the exhaust or air box? Plus was it VERY hot that day?

Paul

[Nick Graves]

Sounds like classic Honda heat soak - mine was a bit cranky on re-start after a long run and the S2000 suffers kangarooing without a cold air intake anyway.

Mind you' I've de-corroded the battery terminals and it seems to fire up a tad quicker now. I'm used to the S starting almost on the first compression stroke!

[rocco1]

Hi rocco, IIRC you have made a couple of changes (mods), were any of these the exhaust or air box? Plus was it VERY hot that day?

PaulThe only mod i made was the wheels and yes it was a hot day.

[Kaz-kzukNA1]

Bit of a off-topic from the initial post but if you are re-starting the engine while the engine is hot, it will help by opening the throttle about 50% and then crank the engine.

This is to push out the rich mixture and I think this procedure is on your NSX Owners Manual.

Hope you managed to find the cause of issue ...

Regards,
Kaz

[NSXGB]

My car suffered occasional hot start problems, if I let the fuel pump prime before I start cranking it's fine. Out of habit now, I wait for the engine light to go out before I crank. . . Never had a problem since.