Euro spec 1.9 tdi Bora / Jetta 115bhp diesel AJM engine does not always start

[toni2has]

Our Sons VW Bora 1.9 tdi 115bhp 100000 miles plus with AJM engine runs OK no warning lights or anything to indicate a problem, but over last few months when switched off it is getting more difficult to restart the diesel engine and we are searching for cause and ideas. The turbo was stripped and cleaned early last year, the diesel tandem fuel pump has been changed again recently and the battery and all electrics appear in good condition. The car appears NOT to be fitted with the combined fuel sender and pump unit in the tank and there are no visible leaks of diesel, nor ny smells of diesel. It is fitted with solenoid valves appears to be two on the engine bulkhead, and I think that these were replaced last year when cleaning turbo unit. Anyone had a similar problem and could throw out some ideas for what to look at next? Thanks in anticipation toni2has

[dieselpnk91]

Well idk if this is much help two months later but mine didnt get quite this bad but did have trouble starting when the engine was hot and i tried jumping in and going again... the fix was when i got the ecm flashed the also did something to it that made it start right up hot cold whatever whenever its awesome. like i said may not be the case here but could be a more extreme case of it.

[toni2has]

From toni2has to dieselpnk91 and all MkIV VW Bora / Jetta and Golf tdi owners.
Many thanks but after after changing diesel pump (only one cam driven bolted to head - no electric lift pump on sender unit in tank on this EU version) luckily I had a spare and saved £350.00 UK costs. However, it was not the pump although the car now runs far better! The problem was eventually traced to an electrical relay (possibly a cold start relay?) which wasw intermittently failing. VAG COM did NOT identify the problem hence a lot of head scartching but its solve now, thanks.