I first posted about this issue several months ago and despite many suggestions from this forum I am still trying to solve this mysterious problem. Rain and frustration has hindered my efforts the past few months but I’m ready to dig in again and would appreciate any input.
My car is a 2005 B5.5 Passat TDI Wagon with a BHW engine. It has 140,000 miles on it and the engine ran perfectly last fall when I began a manual transmission swap. I opted to pull the engine and AT out of the car as a unit and while the engine was out of the car I had a shop do a BSM delete and new timing belt and water pump. I also installed a new coolant manifold, water temp sensor, and engine speed sensor. The transmission is an FHN from Dutch Auto Parts and the rest of the manual swap parts were from a 2002 Passat V6. I’m currently using an ECU with an immobilizer delete that works just fine in my friend’s Passat.
I completed the swap last October and the engine has not run normally since then. This is the current situation when I try to start it:
The cold car starts immediately but starts at a low rough idle, around 450 rpm, which increases to around 950 rpm over a couple of seconds at which point the engine usually shuts down. After a few tries like this instead of shutting down completely it will catch itself and idle very roughly at 450-500 rpm. At this point there is no throttle response (VCDS shows the TPS operating properly), the timing is at 13-14 BTDC, the Specified MAF (SMAF) is 650-850 while the Actual MAF (AMAF) is around 450, and the IQ is 33.8.
It will idle in this condition and gradually warm up. As the coolant temp rises the rpm slowly increases and gets smoother. The throttle remains unresponsive and the timing and SMAF are unchanged. When the coolant temp reaches 56-58 C everything changes-
the idle is smooth and stable at 850 rpm, the throttle is responsive, the timing is within normal specs (1.6 BTDC), the SMAF and AMAF are approximately the same in the 250-450 range, and the IQ is 4.7 The engine revs normally to redline and if I shut it down and restart it, the car runs normally.
The only codes on a VCDS Autoscan are related to the missing TCM which should not effect whether the engine runs properly or not. I have tried 3 coolant temp sensors, the last one from the VW dealer with no change. I’m confident that this is not an ECU issue and I’ve tried a different MAF sensor from my friend’s Passat without any change.
Anybody seen anything like this before? Calling all TDI geniuses to help me get this car on the road. Many thanks.
My car is a 2005 B5.5 Passat TDI Wagon with a BHW engine. It has 140,000 miles on it and the engine ran perfectly last fall when I began a manual transmission swap. I opted to pull the engine and AT out of the car as a unit and while the engine was out of the car I had a shop do a BSM delete and new timing belt and water pump. I also installed a new coolant manifold, water temp sensor, and engine speed sensor. The transmission is an FHN from Dutch Auto Parts and the rest of the manual swap parts were from a 2002 Passat V6. I’m currently using an ECU with an immobilizer delete that works just fine in my friend’s Passat.
I completed the swap last October and the engine has not run normally since then. This is the current situation when I try to start it:
The cold car starts immediately but starts at a low rough idle, around 450 rpm, which increases to around 950 rpm over a couple of seconds at which point the engine usually shuts down. After a few tries like this instead of shutting down completely it will catch itself and idle very roughly at 450-500 rpm. At this point there is no throttle response (VCDS shows the TPS operating properly), the timing is at 13-14 BTDC, the Specified MAF (SMAF) is 650-850 while the Actual MAF (AMAF) is around 450, and the IQ is 33.8.
It will idle in this condition and gradually warm up. As the coolant temp rises the rpm slowly increases and gets smoother. The throttle remains unresponsive and the timing and SMAF are unchanged. When the coolant temp reaches 56-58 C everything changes-
the idle is smooth and stable at 850 rpm, the throttle is responsive, the timing is within normal specs (1.6 BTDC), the SMAF and AMAF are approximately the same in the 250-450 range, and the IQ is 4.7 The engine revs normally to redline and if I shut it down and restart it, the car runs normally.
The only codes on a VCDS Autoscan are related to the missing TCM which should not effect whether the engine runs properly or not. I have tried 3 coolant temp sensors, the last one from the VW dealer with no change. I’m confident that this is not an ECU issue and I’ve tried a different MAF sensor from my friend’s Passat without any change.
Anybody seen anything like this before? Calling all TDI geniuses to help me get this car on the road. Many thanks.
