Dies after an hour of running!!!

[a4trouble]

2008 a4 b7 keeps dying after an hour of driving. It only dies when it's at low rpm's. Like when I'm at a stop or coasting around 15mph. My car won't restart for about 10 to 20 minutes after said death. I asked my friend who works on cars and he said it sounded like a cam position sensor. So I swapped that out and my car seemed to be fine for about 4 or 5 days then the problem came back. I decided to take it to audi and they swapped out my low fuel pressure sensor and the problem still happened. They did further diagnostic and told me that they needed to replace my hpfp. So I did it myself to save money on labor, and while I was in there I swapped out my cam follower. my car seemed to be running a little better but the problem came back...

CODES: P0089, P2294, P025c

I dont want to keep throwing away money, does anyone have any insight on this problem?

[drumnjuny]

damn that must be super frustrating sorry to hear that. i had a buddy who had the same problem with his TSI (not the same motor) and swapping the HPFP fixed it, but it sounds like you've already done that.

i would post in the regional section and see if anyone has VAG COM and can take some logs for you. then you can post them here and some more experienced guys can tell you what looks wrong.

but in the meantime, it would be a good idea to look up these codes on the rosstech site. I just looked up p025c, could be your LPFP controller or LPFP. also could swap your fuel filter to see if its that.

can you give us some more information like mileage, tip/manual, etc?



sidenote: hilariously apt username. for that.

[Charles.waite]

I would try replacing the Engine speed sensor. The Cam position sensor is the wrong diagnosis, as all that send to teh ECU is Cam Phase. If your car dies while driving, its often due to the Engine speed sensor (Crank Speed Sensor) failing. WHen the ECU stops recieving a signal from it it custs spark and kills the engine. The engine will operate pretty much as normal with the cam position sensor failed. I can unplug mine and the car drive just fine and only takes a few more cranks to start.

[a4trouble]

damn that must be super frustrating sorry to hear that. i had a buddy who had the same problem with his TSI (not the same motor) and swapping the HPFP fixed it, but it sounds like you've already done that.

i would post in the regional section and see if anyone has VAG COM and can take some logs for you. then you can post them here and some more experienced guys can tell you what looks wrong.

but in the meantime, it would be a good idea to look up these codes on the rosstech site. I just looked up p025c, could be your LPFP controller or LPFP. also could swap your fuel filter to see if its that.

can you give us some more information like mileage, tip/manual, etc?



sidenote: hilariously apt username. for that.

I'll do that! my car is auto non quattro w/ 115,000 miles. If I do replace the LPFP, how would I go about getting the sediment out of my tank? That way I don't ruin another one!
I felt like the username was fitting!!!

[a4trouble]

I would try replacing the Engine speed sensor. The Cam position sensor is the wrong diagnosis, as all that send to teh ECU is Cam Phase. If your car dies while driving, its often due to the Engine speed sensor (Crank Speed Sensor) failing. WHen the ECU stops recieving a signal from it it custs spark and kills the engine. The engine will operate pretty much as normal with the cam position sensor failed. I can unplug mine and the car drive just fine and only takes a few more cranks to start.

Thanks I'll try that. I'm trying to avoid the costly repairs and do the inexpensive ones first. My next move after that will be the Lpfp and the filter.
But would the speed sensor be affected by turning my heater on full blast? I know it doesnt make sense but my engine doesn't overheat, the temp stays at normal levels (if not cooler) and my engine wont fail.

[Biged243]

What was the cam follower looking like when you replaced it?

[a4trouble]

What was the cam follower looking like when you replaced it?

it was all silver on the top with a dark ring around the edge

[Charles.waite]

Thanks I'll try that. I'm trying to avoid the costly repairs and do the inexpensive ones first. My next move after that will be the Lpfp and the filter.
But would the speed sensor be affected by turning my heater on full blast? I know it doesnt make sense but my engine doesn't overheat, the temp stays at normal levels (if not cooler) and my engine wont fail.

Nope. All the engine speed sensor does is relay the position of the crankshaft to the ecu so it can properly time fuel injection pulses and ignition timing.