2005 TDI Hot Starting Fault

[nixamus]

Hey all, I have a 2005 TDI Golf with the BKD engine, and am having trouble starting when hot.

When the engine is cold, it starts fine but when it is up to operating temperature it cranks over a lot before it starts.(maybe 5 seconds) I thought maybe fuel??

Does anyone know how to test fuel pressure in the rail itself, or are there any spec's for this??

Please help!!

[nixamus]

Car has only 85,000km on it!

[kenney]

Hi The delivery pressure,is checked on the tandem pump.With an engine speed of 4000 rpm there should be a min pressure of 10.5 bar.Have you had a fault code read,I suspect maybe you could have a dodgy temp sensor.

[nixamus]

Hey, Scanned with VAG no fault codes, temp seems fine on gauge and on VAG and temp sender got replaced 4mths ago.

Fuel pressure is fine, however when i turn the ignition on it raises to 10psi, then drops right down, shouldnt it hold pressure?
I heard that maybe #458 relay next to battery can cause this hard hot starting?????

Thanks for all input.


Nixamus.

[kenney]

I doubt if the problem is the 458 relay, had it been the case,i think you would have had the same problem cold or warm engine.If you have a pressure of 10 bar from the tandem pump,then the delivery pressure is ok.There is no specified holding pressure for the pump,as you say the pressure rises and drops when you turn the ignition on.There is however a control for internal leaks,for which you need a special tool VAG 1687.Have you checked the engine oil can you see any signs of contamination?Regarding the temp sensor you replaced,was it an original VW part?,

[naz5]

Hi Nixamus.

I had a similar problem with a bmw 2003, actualy the problem was very very similar, wen the car was cold it was fine, after 13mins drive, warmed up and the engine cut out automatically, would take 20secs to start, then again after a few mins would cut out, always fine wen the engine was cold, but as soon as it warmed up, bang, gone, no codes watsoever woud come up on the diagnostics, dealer didnt av a clue on wat it was, changed camshaft sensor, crankshaft, mas air flow meter, fuel sensor nothing was any good, finally took it to a local garage, after a days of serching under the bonnet, there it was, it was infact the broken relay and its loom, right next to the battery, if i were you id get you to get that checked before you spend any more money, i hope this is the problem as not knowing is bad, time consuming, expensive and dangerous,

Now im loving live with my mk5 1.6 fsi

[nixamus]

What is the procedure for checking internal leaks with VAG 1687. Temp sender was again replaced, and it is a geniune part from Austral. I'm starting to dislike cars very much :confused:

[nixamus]

what colour is wiring/replay? do you have any pic's?

cheers

nixamus



Hi Nixamus.

I had a similar problem with a bmw 2003, actualy the problem was very very similar, wen the car was cold it was fine, after 13mins drive, warmed up and the engine cut out automatically, would take 20secs to start, then again after a few mins would cut out, always fine wen the engine was cold, but as soon as it warmed up, bang, gone, no codes watsoever woud come up on the diagnostics, dealer didnt av a clue on wat it was, changed camshaft sensor, crankshaft, mas air flow meter, fuel sensor nothing was any good, finally took it to a local garage, after a days of serching under the bonnet, there it was, it was infact the broken relay and its loom, right next to the battery, if i were you id get you to get that checked before you spend any more money, i hope this is the problem as not knowing is bad, time consuming, expensive and dangerous,

Now im loving live with my mk5 1.6 fsi

[kenney]

Hi I doubt if the pics from naz5 will help you,as he is talking BMW.I would suggest a scan of the PD units in measuring block values