Drivability issue after track day
09-02-2018, 05:53 PM
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Drivability issue after track day
Yesterday I was Streets of Willow tracking my 2006 AP2 back to back sessions in 95 degree weather. On the very last session while waiting at the grid my idle sporadically started to dip and then would catch its self. I was little concerned but did the session anyways and the car seemed to drive fine. Then leaving the track, under light load the car would hesitate and buck almost as if it was hitting fuel cut. I Limped the car to the gas station and let it idle. The idle dipped so bad the car stalled. So I reset the ecu by disconnecting the battery and tried again, idle was still sporadic and by this time I said f it and drove the car back to Orange County. Getting on to the freeway had the same slight hesitation and bucking but managed to get it up to cruising speed and drove very conservatively for the next 50 miles maybe. By this time the car seemed to fix its self and no more hesitation or inconsistency in idle since I eventually hit that LA traffic lol. Fast foward to today the car idles and drives normally, took it to auto zone to scan the ECU and a code came up for the thermostat: P0128
Sorry for the long drawn out post but does anybody have some insight on what could cause the drivability issue? Could it be a bad injector, dirty air filter (have a k&n which does look pretty dirty), bad thermostat, etc.
Everything is stock engine wise besides K&N filter and Test pipe.
Sorry for the long drawn out post but does anybody have some insight on what could cause the drivability issue? Could it be a bad injector, dirty air filter (have a k&n which does look pretty dirty), bad thermostat, etc.
Everything is stock engine wise besides K&N filter and Test pipe.
Last edited by CR295; 09-03-2018 at 07:40 AM.
09-02-2018, 06:15 PM
#2
First thing I would investigate is a vacuum/intake manifold leak. I would look at the idler control valve as well.
i would then Check spark plug coils although that should have shown up on the scan.
Both problems can actually occur occur at times only when the motor is good and hot then return to functioning when it cools and under easy load.
i would then Check spark plug coils although that should have shown up on the scan.
Both problems can actually occur occur at times only when the motor is good and hot then return to functioning when it cools and under easy load.
09-02-2018, 08:31 PM
#3
I've had exactly this happen after track days a couple of times too. Exactly as you describe—mostly at idle and a bit cruising at low revs. Only happens immediately after track days (never during) and always seems to resolve itself pretty quickly. FWIWI know it's not spark plugs as I just changed them (and it happened both before and after). Have never gotten an ecu code from it though. Will be curious to hear what you find. My uneducated guess was maybe a dirty (or bad) MAF sensor, but I haven't tried cleaning it yet.
Edit: MAP sensor, not MAF. Sounds like another possible culprit is the IACV (Idle Air Control Valve).
Edit 2: Not the IACV since we both have DBW cars, which don't have one.
Edit: MAP sensor, not MAF. Sounds like another possible culprit is the IACV (Idle Air Control Valve).
Edit 2: Not the IACV since we both have DBW cars, which don't have one.
Last edited by Nate Tempest; 09-02-2018 at 09:21 PM.
09-03-2018, 05:41 AM
#4
it happens when the pcv system dumps oil in the intake. pull off the intake tube and look in the throttle body. if u see pools of oil there u go. it also explains why it gets better with time.
09-03-2018, 07:42 AM
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