91 NSX with 172K is missing after warm up on accel.

[costa92627guy]

I have a 91 NSX, the car runs great when cold, no misses. When it warms up and I am idling along on the freeway in 5th, then I give it gas, it misses (girgles) a bit until I give it a considerable amount of pedal. Same thing happens in any gear at low RPM, I basically have to put the clutch in and rev the engine to break through the miss. Other than that, it runs great. I have not had a chance to bring it in for a diagnosis. Any ideas? Thanks.

 

[Briank]

Check engine light?

 

[warren1205]

My friend, spark plugs need replacing! Don't bother checking anything else.

 

[Larry Bastanza]

mmm........I am thinking you have some very tired 02 sensors. Your description sounds like this is happening only when the 02 sensors are in use (closed loop mode)

Go here, read this thread, and follow post#5:

http://www.nsxprime.com/forums/showthread.php?t=104320

This procedure will also work with your 1991, so no worries I originally advised this for a 1995+ car. If you disconnect the sensors as described and the car runs fine, you have found your issue. This test is free, so it is the best starting point.

HTH,
LarryB

 

[costa92627guy]

Yes, check engine light comes on, and shortly thereafter it happens. Thanks for all your input!

 

[Larry Bastanza]

Yes, check engine light comes on, and shortly thereafter it happens. Thanks for all your input!

With that in mind, the first thing to do is get the code. That will tell us a lot to pinpoint the issue. Before you run the test I mentioned above, I would get the code first, so you are reading what the ECU thinks it is now, rather then the self-induced codes you will get from the test.

HTH,
LarryB

 

[costa92627guy]

I pulled the rear 02 sensor plug and it is much much much better. There is still just a little build up occasionally, nothing like it was before. Is it possible the front 02 sensor could be slightly failing? Next I will pull the front one. I was hoping to only change one if I could get away with it. Now I can drive the car! :biggrin:

 

[Racerxjling]

I pulled the rear 02 sensor plug and it is much much much better. There is still just a little build up occasionally, nothing like it was before. Is it possible the front 02 sensor could be slightly failing? Next I will pull the front one. I was hoping to only change one if I could get away with it. Now I can drive the car! :biggrin:

You should really change the O2 sensors in pairs (cheap insurance esp. with the way your car is running and the mileage). Buy the aftermarket NTK sensors from SOS...way less $$ than OEM. Plugs not a bad idea either if they haven't been changed either. Do you have maintenance records?

Jeff