Misfire on Idle

[mart155]

I know I spoke to some of you about this at the marathon car wash weekend recently as I thought the car was running very lumpy on tickover.

I have now decided that there is a definite misfire until the revs pick up to around 2k and then it is fine.
I realise that there are a number of possible reasons for this and would welcome any suggestions.

My favourite suspect at the moment is an ignition coil but I have no idea how I can identify which one of the cylinders is misfiring. Has anyone got any ideas.

Does anyone have a couple of spare coils (1 front & 1 back) that I could possibly borrow for a weekend so I can swap them one at a time.
Thnx
Martin.

[goldnsx]

I had exactly the same symptom and went with 3 new coils in the rear. I only needed one but I was too lazy to find out which one.
I have used 3 coils for sale, 2 of them are good. Let me know if you're interested.

[Kevin]

Have you checked for water? Especially on the rear bank?

Remove all the coils, make sure its dry around the plug. If there is rust on the earth contact on the coil, rub that off with wet&dry. Then grease with electrical contact grease.

I had a hiccup at 3000rpm for a while, until I cleaned everything up.

[goldnsx]

For checking which one is bad unplug the connector to the coil. Try this for cyl. 4, 5 and 6, only one by one and the engine off. If the idle doesn't get worse you have a candidate. ;)

[AR]

It seems this is the "engineered" fault that the NSX has by having an open rear window garnish. One of my NSXs had this problem. On my current one I had all seals replaced when doing the service to try and prevent this. I also garage it and I am mindfull when washing it.

If you do a search on prime, you will noticed that the NSX engine does have a bit of inherent lumpiness as the V-Tec cams were still a bit primitive.

Cheers,

AR

[Nick Graves]

That's also because it's a 90 degree V6, it has a lumpy idle. Sounds like a three-pot!

If it's not a coil, it could be too tight valve clearances, which can burn out a valve seat.

Best get it checked sooner, rather than later.