Early B7 1.9TD 115 BKE intermittent start issue

[craigshaddick]

Hi, first post here. I've done a long search but am having no luck.

TLR - car sometimes does not fire unless you spray Easy Start in

I've had 30+ VW and Audi's over the years, most have been pretty reliable but this one is really testing my patience! There's not much I haven't replaced on this car in the 5 years I've had it but I suspect something in the fueling system is feeling unloved as I'm yet to touch that...

I drove the car to work last week, went to start it up at the end of the day and it wouldn't fire, the engine was cranking but would not kick in. Called out RAC who tried cranking for a bit (with a battery pack on it as it was draining the battery) with no luck, so chucked a load of easy start in which made it fire up. He said he thought it was Glow Plugs... I replaced these the next day even though the old ones looked OK, but no luck. I called RAC back out as I have home start, the next guy did exactly the same to get it going but also plugged in his diagnostics tool just in case - no faults.

The second RAC guy was a VW nut so was really helpful - he said he thinks it's air ingress in the fuel system as it had only happened after leaving the car for 6+ hours. It could be a leaky injector which would probably cost £1k to even do one due to it being under the cam... or possibly the fuel pump. He did say before taking it to a garage it may be worth trying to replace the Fuel Filter as it could be that, I had one in the garage so I filled a new filter with fuel and installed in 10 minutes, and the car fired straight up! It was OK for a few days, and turned over instantly which is better than usual, but then the issue happened again.

The time sitting doesn't seem to be related as at the weekend I drove the car for an hour, stopped in a supermarket for half an hour and then it wouldn't start again. I've now got a Nocco battery pack and Easy Start in the car so I can get it going if I am stuck but it's not feasible. I just went outside after it being sat for 2 days and it started on the button.

Does anyone have any ideas of things I can try? There are no related codes coming up on VCDS - Only codes are for dead ABS sensor and AC compressor which I have replacement parts for.

Thanks in advance!
Craig

[Crasher]

Your car has glow plug monitoring, if one was faulty it would be flagged as a fault code AND the glow plug warning lamp would come on. The injectors are not under the cam, they are adjacent to it and can be removed after removing their rocker shaft. My first step would be to replace view the cold cranking rpm, this requires a suitable diagnostic system with measuring blocks and for the injectors to be disabled to prevent starting. The test takes about 20 seconds of cold cranking so a good battery and the rpm displayed must be no less than 280rpm. Then the injectors are reconnected and the fault codes this test has generated have to be cleared to prevent future confusion. If this proves to be acceptable, the first part I would change is the crank speed sensor called G28 as these produce the symptoms you are experiencing and hardly ever leave a code.