I'm having a problem with my son's 916 Strada misfiring when it's hot. It has just had a belt change and new plugs fitted and was OK before. It starts ok and runs fine until it is warm and then quite suddenly starts overfuelling badly. First thing was to swap the plugs back to the old ones - no difference. Then tried replacing the coolant sensor with a spare - no difference Unplugging the air temp sensor also made no difference Although I couldn't see why it should suddenly go wrong I thought it best to check the TPS voltage. On measuring across pins 11 and 17 of the P8 chip I measured 4.89V and it didn't change as the throttle was opened. So I thought I'd found the problem. I checked for continuity from the ECU to the TPS connectors and found no connection between pin 11 (ECU ground) and the TPS connector red/white wire. Undoing the round connector at the throttle bodies I could get continuity to the centre pin so it seemed that the connector wasn't connecting properly. I widened the end of the pin slightly and squeezed the socket slightly and all seemed OK when put back together but on the road the same problem came back. Thinking it might be a break in the loom or the throttle body sub-loom I now ran a wire direct from the ECU to the TPS, by-passing the red/white wire. But still the problem persists. I'm beginning to think I'm chasing the wrong thread here. The only other thing i can think of is the TPS itself. Anyone got any other ideas?
A similar approach to another thread running at the moment is probably the answer as there are so many possible culprits. Have you checked the absolute air pressure sensor to see if it's filling up with water or has corroded pins on the connector? The injector loom connector (which you checked) is often overlooked as is the main, similar but larger connector on the right hand side just behind the radiator.
