excessive

Engine is 4.0 tdi. It is been a month since I've started experiencing this. It happens 99% of the times the car is started, no matter if its hot or cold, if it's been running for long or not. I just start the car, and there's little response in P. Up to ~1200 rpm, but if I shift to D it's even worse since there is no response at all, and I have to wait a few seconds and then suddenly the throttle will "comeback". No matter if I pump the pedal or just push it WOT it is the same for 5 to 15 seconds. Afterwards it will be fine until I stop and turn it off.

Diagnostic shows P0102 Mass Air Flow (MAF) Circuit Low error. I've bought two MAF's one used from same car and one brand new (PIERBURG). I've tested all possible combinations of using them (since the car has two MAFs, one for each turbo), with or without MAFs the error is same and the car keeps its behaviour.

I have also changed oil + filter and fuel filter.

Dville

Are you using just a OBD code reader or VCDS?

excessive

Couldnt find VCDS in the area so im using Autocom and Launch X431 Pro for now.

Dville

You are aware that the VCDS would probably tell you exactly what is wrong with your car after scanning all modules.

Jack88

Check the wiring and connector for any signs of corrosion or decay. Also check any vacuum lines for possible leaks. I can't say I'm familiar with that fault on that motor, but those are easy things to check, so might as well. My guess is that time delay is how long it takes for the car to decide to ignore that particular sensor input and run off of a default assumed value.

MP4.2+6.0

+1 on VCDS. Others are often pretenders/time wasters.

Mister Bally

Available world wide via various shipping companies. If your car got somewhere, Ross-Tech can ship a VCDS interface there. Not available in stores. But you gotta act now,...

excessive

I'm on the same page on this. I think car's ECU just takes time to adapt without the particular readings. But I've checked my wirings and they are ok. Tried examining the vacuum lines, but it's pretty hard to reach anything on this engine

Jack88

You could still have an intake leak, spraying starter fluid could confirm it. It the engine revs, you've sprayed near a leak. If everything is sealed, nothing will happen. The MAF code makes me think if it's not the MAF, it's something in the immediate vicinity, either another sensor or the things immediately next to it.

excessive

Just to add one more dimension to the problem:

Today I started the car for first time since Tuesday. It's cold here so explainable the rpm went over 1k at first, but the throttle was VERY responsive in P, R or D. After driving for 2 minutes I stopped at local market. 30 min later started and everything was just like before - no throttle in D, the pedal felt "delayed" etc..