Rough Idle

[JChoice]

I checked the FAQ. Unfortunately, I haven't been in too many other NSX's but my NSX seems to have a rough idle - all maintainence has been done although I don't know if the O2 was replaced. The tach is rock solid at idle but there just seems to be a pretty good amount of engine vibration and noise in the cabin area at idle.

Is that normal?

 

[Larry Bastanza]

First thing to do is to get to another car to compare. It is hard to describe this kind of thing in the forum. Usually the rough spot is around 1400-1500prm. This rpm roughness is generally during the warm-up phase. Is your idle around 750rpm-850rpm? If the idle is higher, let's say near the 1400 rpm mark, check your temperature gauge, you may need a thermostat.

HTH

 

[JChoice]

I've read through the FAQ and am aware of the 1500 problem. I'm talking about warm idle at ~800rpm. I don't know anyone with an NSX that I see on a daily basis so I don't have anything to compare it to - just seems a little rougher than it needs to be considering the fact that the car has been religiously dealer maintained.

 

[AndrewB93]

Engine Mounts maybe?

 

[Dave]

It may be the Throttle body needs to be cleaned. I have seen this on numerous NSX's and Legends, etc..With engine OFF, Simply open throttle blade and spray a good high quality carb cleaner to clean off throttle body internals and the throttle blade itself. Then remove idle adjust screw and spray thru hole and clean tip of the screw as well. There will be a considerable amount of black carbon and junk to clean off. It is normal residue. When you start it back up, it will run rough for a bit till it gets all of the carb cleaner burned out, but then adjust idle to specs. You will be amazed at the difference. If you feel uncomfortabel doing this small operation, simply take it in to your dealer and ask them to clean it for you.. Less then 35.00 usually.

 

[davidf]

Normal. I've had my car a year and I'm still not use to it.

 

[NSXFRIEND]

I checked the FAQ. Unfortunately, I haven't been in too many other NSX's but my NSX seems to have a rough idle - all maintainence has been done although I don't know if the O2 was replaced. The tach is rock solid at idle but there just seems to be a pretty good amount of engine vibration and noise in the cabin area at idle.

Is that normal?

NSX has a 90° V6 rather which is not as smooth as a 60° V6. Another possibility is some small amount of dirt or crud sticking to the mass air flow sensor and/or some of the other sensors that hang in the air stream.

http://www.nsxprime.com/FAQ/Troubleshooting/roughidle.htm

 

[Briank]

Then remove idle adjust screw and spray thru hole and clean tip of the screw as well. There will be a considerable amount of black carbon and junk to clean off.

Do not remove the idle bypass screw, its sealed over for a reason. The idle speed is controled by the ECU and the idle bypass need to be properly set so the ECU can do its job.

That being said try the engine centering procedure which takes care of most vibration complaints.

http://www.nsxprime.com/forums/showpost.php?p=378268&postcount=2