Fluctuating Revs During Warm-up

[RARNSX]

I've researched Prime but could not find any FAQ's directly related with my problem.

Lately, when starting my NSX in the mornings (car is garaged), the tach revs up to 1600 rpm for 10-15 seconds then starts to rev up and down between 800-1200 rpm for 2-3 minutes. It finally settles down to about 1000-1100 rpm until the engine warms up then idles at 850 rpm.

While I was up in Monterey, CA last month, with colder nights and the car parked outside, the up and down reving lasted for about 5-7 minutes before settling down.

Hitting the accelerator during the up/down reving period does nothing.

Does anyone know what might be causing this fluctuation in revs during warm-up?

 

[goldNSX]

What did your tech say? Does it throw any trouble code?

 

[KooLaid]

sounds like a possible dirty throttle body to me. Common problem. Simple search should yield some answers.


http://www.nsxprime.com/forums/showthread.php?t=92914
http://www.nsxprime.com/forums/showthread.php?t=75911

 

[goldNSX]

I'd have said the same but getting any error-codes first simplificates the solution.

 

[ChongLee]

havent experience on the nsx yet, but as i recall on the mr2,
it was due to a vaccum leak, somewhere between the intake
and throttle body. again, not sure if its the same for the nsx.

 

[MashimaroNSX]

try some throttle body cleaner

 

[nsxtcy85]

Mine does that also. Always has.

 

[nsxtasy]

I experienced a similar problem on mine last year at NSXPO 2006 at Sebring. Only in my case, it wasn't just during warm-up; it was happening when the car was hot, too. When I came off the track, the idle was varying between 1500 and 2500 RPM. We* tried spraying cleaner on the throttle body and idle control valve, but it didn't help. We* then replaced the idle control valve and that cured the problem.

* "We" = Nabil and Oster at First Class Automotive - thanks, guys!

 

[RARNSX]

What did your tech say? Does it throw any trouble code?

Don't know. Haven't had a chance to take it in yet. I'm debating whether to take it into my Acura dealer, AutoWave or a good friend who is a Honda specialist mechanic.

But, thanks to all who responded. There is a wealth of information to consider. Hope to resolve this soon. Will post the solution.