db252
Veteran Member
Rough idle - checked IQ - What do you suggest (Updated)
The details:
ALH 2001 Golf with 140,000 miles and an auto transmission.
Timing belt, fuel filter, glow plugs, and harness were all replaced along with air filter approx 10,000 miles ago.
No CEL or stored codes.
MAF is good.
Starts great every time.
When driving the car it runs perfect even when stopped and idling.
It's when you put it in park or neutral that it begins to idle rough.
I hooked up to vcds to check timing and IQ. Timing is spot on. The IQ while idling in park or neutral is all over the board from zero to 3.x and everywhere in between which is most likely the cause of the rough idle. Now put the car into drive or reverse and the IQ goes to 3.5 and stays there with no rough idle.
WHY??
Tried searching all over and have some basic areas to start looking but hoping for more insight from the members. Haven't found anyone with same symptoms of being in gear or not with the same results. Everything I can think of points to the IP but again, why would it work perfectly while in drive or reverse?
What say you?
The details:
ALH 2001 Golf with 140,000 miles and an auto transmission.
Timing belt, fuel filter, glow plugs, and harness were all replaced along with air filter approx 10,000 miles ago.
No CEL or stored codes.
MAF is good.
Starts great every time.
When driving the car it runs perfect even when stopped and idling.
It's when you put it in park or neutral that it begins to idle rough.
I hooked up to vcds to check timing and IQ. Timing is spot on. The IQ while idling in park or neutral is all over the board from zero to 3.x and everywhere in between which is most likely the cause of the rough idle. Now put the car into drive or reverse and the IQ goes to 3.5 and stays there with no rough idle.
WHY??
Tried searching all over and have some basic areas to start looking but hoping for more insight from the members. Haven't found anyone with same symptoms of being in gear or not with the same results. Everything I can think of points to the IP but again, why would it work perfectly while in drive or reverse?
What say you?
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