Larry_Fopps

The past few months the car has been having a problem after its been heat soaking on a warm engine. When I start the car from cold start, it fires right up and idles and runs as it should. If I park the car after its reached operating temperature, and let it sit for 30-90mins, when i come back to start it , it fires right up but idles really low and throttle is non responsive unless i hold it down for 10sec and it slowly builds the revs and then everything is back to normal. Also, if i switch the ignition off and hold the throttle while starting to give it an immediate high rev kick I also will have throttle. These two methods are the only way to regain throttle. Once it has this issue, and I manage to regain throttle, its extremely laggy in lower rpms, but the throttle then is suddenly extremely touchy and the car will take off like a rocket ship giving it barely any throttle.

The only code the car throws is a rear o2 no activity intermittent, and internal resistance too high rear o2 code. Nothing throttle or epc related at all.

Things I've done so far:
Brake Light Switch. OEM I had a fault for this and i also have read it has caused no throttle issues for other people. Did not Solve
Swapped the Throttle Body OEM with a known good one. Did not solve
New Coolant Temp Sensor OEM when I did my coolant flange. Did not solve

1.8t
Stage 2 Unitronic Tuned

Anyone have this issue in the past or have any suggestions?

Thanks in advance.

Kris Hansen

Have you tried an OEM computer?

Larry_Fopps

I have not yet, due to immobilizer. It may just have to be my next course of action.

Larry_Fopps

Ecu was replaced. Same issue remains. I did some logs today and upon throttle loss i put my foot to the floor. Pedal position read 100% throttle position read 14%. I don't suspect the throttle body because i've already swapped it. In my logging today, i noticed my maf was only reading 1.7 g/s and I've been told it shouldn't get below 3g/s. I'm going to swap that tomorrow with one i have on another car and see if that changes anything.

Prospeeder

You have done the throttle adaption with vagcom or some scan tool that does it? Have you considered the pedal unit itself? This is a drive by wire car right?

Larry_Fopps

Throttle body alignment has been done in vagcom and it passes. When measuring the pedal in measuring blocks it is working according to how it should however the throttle body doesn't follow suit. I swapped the throttle body and it didn't solve anything. I also swapped the ecu and didn't help. I'm going to put the car back to stock and see what happens then.