I just put a CAI on my s2000 and just started having this odd starting problem. When the car is completely cold, and I give it the first start of the day it fires up and holds around 1500RPM like it normally should, then about 2-3 seconds after starting, the RPM drops and the engine starts to heistate and sounds like it wants to stall (lasts about 2-3 seconds) and then it resumes it's normal cold start. After doing this, it will not do this again until the next day (after it sits overnight). Does anyone have any ideas about what this could be?

Also what happens if you turn the knob on the Mass Airflow Sensor that's mounted to the air box? I may have done this accidently when putting the CAI in.

Thanks,
-Chris

 

Looks like no one else is going to tell you there is no mass air flow sensor on the S2000. So I just did.

I'm not sure what you turned, but all I can think of is the throttle position sensor. If you moved that, then the TPS could be telling the ECM the throttle is open more than it really is, which can screw up the idle.

Since it only has a problem when stone cold, it can't be far off from normal and the ECM may learn the new setting in a week or so. Drive it and see. If not, maybe a trip to the dealer.

 

That's no knob, nor the TPS or Mass Air flow sensor. You turned the fresh air filter on the Air Pump control solenoid. They normally spin, and you didn't change any adjustment.

As far as your problem goes, did you disconnect the battery before installing? If you did you need to do the idle learn procedure. Let the engine run at idle with no accesories on, until the cooling fans cycle. Failing to do the idle learn tends to mess up the PCM correcting idle speed with the IAC.

 

Ok I'll do an ECU reset and let it idle. I did reset the ECU after installing the intake, but when I finished I got too excited and took it right out for a test run.

Incidently I did observe that when my car did the hesitation thing this morning, it happened right when the electric air pump kicked on.

Thanks again for your help!