Mis firing 2003 vectra 2.0dti

**dezzypoole** · 19th June 2009, 08:30

Hi,can any 1 help.Ive just bought my vectra 2.0dti 2003 and its developed a little missfire/hesitation between 1000rpm and 1500rpm.If i hold accelerator at 1200 rpm it will rev it self to 1500rpm then back to 1200rpm.
If i disconnect temp sensor the car runs perfect but cooling fans stay on permanantely.Have changed temp sensor twice from vauxhall and no diffrence.
Took for diagnostic yesterday and only thing found was ambient temp showing -40c and coolant temp -16c,possibly over fueling if it think its cold??
Thanks for any replies/help
Dez

**Diet1985** · 19th June 2009, 08:39

i know its not the same car or anything.. but i had he same thing happen to a 2.0l VW BORA i had.... noone could ever find the fault.

**John LE** · 19th June 2009, 11:21

Don't know if the DTi's possibly have separate temp sensors, i.e one to run the cooling fans and another to tell the ecu when the car is hot/cold. Possibly the latter is the one that you need to replace

**FlatheadFordV8** · 19th June 2009, 11:51

As it is showing two temperatures that are obviously wrong, then it will not be a fault with one sensor.

There could be a problem with the supply voltage to the two sensors, or with the module that interpretes the readings.

There may also be a short in the wiring, but this is unlikely, if the problem is improved by unpluging a sensor, as the short would still be there.

**dezzypoole** · 19th June 2009, 21:51

Thanks for all replys
Cheers dez

**dezzypoole** · 21st June 2009, 08:50

Had car in today for third time,now being told it may be fuel pump.
Unsure about this,as if i unplug temp sensor car rins perfect.
COULD FUEL PUMP BE AT FAULT??????

**FlatheadFordV8** · 21st June 2009, 11:24

Sounds like they are guessing to me.

Ask them to explain why they think it is the fuel pump.

**jim bray** · 10th February 2011, 22:48

Did you find the problem as mine is the same.

**roswell** · 11th February 2011, 00:29

2.0 dti have a habit of killing crank shaft sensors, miss fire / hunting is a symptoom normaly only once upto running temp. replace ment is £40 ish, its on the front of the engine block under the metal pipe from the intercooler to the turbo ( hence why they normal fail when hot )