98'nsx-t rough idle after 105k service

[dlynes]

Recently had my 98'nsx-t serviced for the 105k check up...timing belt, water pump. also new comptect clutch/flywheel, and new 02 sensor. After I got the car back, the idle got really rough. it fluctuates from as high as 1500 rpm and as low as 250 rmp...the car has even turned off because it idled so low...just wondering if anyone has ever expierenced this or had any insite?...3 months later and apparently acura has yet to find the problem...they supposedly ran a system diagostics and came up with nothing...everything supposedly checked out right...

thanks guys

 

[WOODY]

dirt/oil on the o2 sensor?

 

[Briank]

First thing would be a good throttle body cleaning then check for vacuum leaks.

 

[brandonsan]

Sounds like the cam timing (belt might be off a tooth or 2) is off. I know the dealer did the work but it is possible. This problem would not show up on a typical diagnostic scanner.

 

[Larry Bastanza]

I agree, remove the valve covers, check the cam timing, especially the rear exhaust cam. If she idles like a V8, this is a likely cause.

The engne should run exactly as it did when you brought it in, unless there was something else wrong you brought it in for. In that case it should run better, not rougher.

HTH,
LarryB

 

[dlynes]

bump

 

[Shumdit]

Why did you bump it? 6 months later and you still have the problem?

 

[Daedalus]

Yeah, is it intermittent, or have you just been living with it?

check for vacuum leaks.

^ my first guess.

Maybe a bad MAP connection at the harness?

 

[Da Hapa]

I agree, remove the valve covers, check the cam timing, especially the rear exhaust cam. If she idles like a V8, this is a likely cause.

The engne should run exactly as it did when you brought it in, unless there was something else wrong you brought it in for. In that case it should run better, not rougher.

HTH,
LarryB

This was exactly the problem with my 1998.

You bumped this thread but haven't given any updates on what has or has not been looked at. That might be helpful to those of us trying to help you.

 

[Joe Gliksman]

I had this at the same mileage, and cleaning the throttle body fixed it.

 

[IFIXEM]

Make sure the cooling system has been bled well. Air pockets in the cooling system can cause idle surge. The ECT sensor can be getting inacurate readings. You did say the water pump was replaced right?

 

[garyn]

I had the same fluctuations at idle. I got a 5mm. overbore throttle body from SOS. Replaced it and recieved a credit for mines when I returned it to SOS. Car idles perfectly and accelerates much better than stock. Their chip also makes the car more responsive. I also returned my stock ECU for credit.