Starting Sharan when engine is hot

[jomaz]

Need help URGENT
I have a VW sharan 1.9 TDi Starts first time in morning when engine is cold , perfectly. but then when the engine is turned off it really stuggles to restart. As i have no engine management light on, and the car runs perfectly at all other times some told me it was a faulty heating sensor . IS IT? also where the hell is it, as i have no idea. please help. :zx11:

[Lex Luthor]

Could be the coolant temperature sensor.
Cheap enough to change on spec.
A four wire sensor sat in a water pipe probably on the rear of the cylinder head.

[jomaz]

Thank you lex i will try that, can i get this sensor anywhere or do ineed the vw garage which is about 20 mles away. regards jomaz

[Lex Luthor]

GSF or Eurocarparts will mail order it.

[boomboomer]

Is it a PD engine or the earlier injector type?

If it's the earlier type then the pump timing can cause hot starting problems - especially if the cambelt is getting a little worn or has just been changed.

[cbrpaul]

this is looking like a common problem worldwide !!!
Owners have spent £100,s on this without any joy

I too have this problem :mad: , ive done alot of research over the last couple of weeks , , and it seems many different little faults can cause this 1 same fault !!!

here is a list that can cause this :

As mentioned , Incorrect timing
Fuel starvation
Air leaks
Injector/s blocked
Faulty starter motor ( not turning engine fast enough )
Battery not strong enough
Main power relay faulty
Main Deisel pump advance timing device faulty sticking ( not pd)
coolent sensor
Fuel temp sensor

That is jsut a few things ive managed to find out so far

Ok now here is something you can do , that will proably work it does on mine !!

Disconnect your coolent temp sensor when your engine is hot , now on a 1999 AFN 1.9tdi, its on the front of the engine to the right stuck in the side of the coolent pipe ,

Once off your engine will start 1st time in less than the a second ;) !!!

Go try it and let me know how you get on ,

Oh and why should this not happen on cold starts , well because the ECU changes various things on a cold start

:beerchug:

[cbrpaul]

I measured the resistance of my coolant temp sensor and its reading double what it should be accorodng to the VW repair CD , so replaced it yesturday , with a £11 1 from my local partco place, VW wanted £26 :aargh4:, which apprently are not very reliable!!

I also sprayed the starter motor with WD40 ,

I have noticed 2 things now

1:The fan does not always come on now , before it was coming on even after turning engine off when the engine was not that hot to touch , hence false reading telling ECU toturn fan on !!!

2:Starting seems much more better !!! hot and cold !!!

:beerchug: