Intermittant starting - engine speed sensor advice needed urgently (please)

[MOZ-IIIVR6 0]

Hi guy's, Long time since I last posted. i have what seems to be a commonish problem ( I have searched on here with interest but still have some questions).

The problem is that intermittantly after a drive (no apparent problems running) if I stop ( say for petrol) the car won't start again ( engine turns over but no firing whatsoever). After approx 15 to 20mins the car will finally start with no problem at all. This has occurrred 5 time in th elast week and every time restarted after 15 to 20 mins.

Took it to Stealership who have diagnosed engine speed sensor ( plausable I thought) they have changed it and now claim the fault code is still there ( they say they have done this with the engine running !!) and now think it is the engine speed sensor control unit? ( which they can't fit till next Tuesday ( which gives me a bit of time for some alternative advice).

Any one heard of this control unit before as I cant find any mention of it on here ( it is obviously more expensive that the sensor. £200 hard earned snotts) i would have expected the sensor to go directly to the ECU itself?.

2 questions:

1)

Would this fault cause the symptoms I have and if so why does the car start at the dealership with the fault code still present if this really is the problem( I have posed this question to them)I suppose it could just be luck that the point of firing and fault don't appear together all of the time?

2)

is there anything else that can lockout or cause the ECU to disable firing that the ecu tries to automatically reset after approximately 15 - 20 mins?

Any suggestions would be welcome.

Thanks.

MOZ

[kilokilla 0]

Hi mate i have had cars do this before because of the blue temp sensor being faulty basically they send the wrong signal once car is warm so when you go to restart its giving wrong readings to ecu and wont start im not saying this is your prob but its worth looking into as the blue sensor is only about £15 try warming car up then turn off make sure it wont start then unplug blue temp sensor and try starting car again if it then starts this is your prob.

[6potmkII 0]

Hi mate i have had cars do this before because of the blue temp sensor being faulty basically they send the wrong signal once car is warm so when you go to restart its giving wrong readings to ecu and wont start im not saying this is your prob but its worth looking into as the blue sensor is only about £15 try warming car up then turn off make sure it wont start then unplug blue temp sensor and try starting car again if it then starts this is your prob.

can the blue or yellow sensor make the engine run bad i.e. intermittant missfire?

[kilokilla 0]

I have known the blue temp sensor to cause a slight loss in power and make it crap for starting but i havnt come across 1 causing a missfire yet,the most common thing ive come across for intermittent missfire is coilpack.

[Nerih 0]

yeah i would expect a warm start issues to be temperature sensor/thermostat related, good luck m8.

[MOZ-IIIVR6 0]

Cheers for the suggestions. It looks like it was the engine speed sensor, got changed today and touch wood seems to have fixed the problem.

Thanks again.

MOZ

[Guest Mosley]

Hi mate, I have had 2 cars with this problem.. after turning off engine took about 15-20 mins before even sounding like it was going to fire up..

Both times I had a new distributor which cured the problem, I was told that it was the hall sender unit in the distributor causing the problem, apparently over heating..

Do you have a distributor or coil pack!!!!! Might be worth looking at if you have a distributor.

[MOZ-IIIVR6 0]

Hi Mosley,

Thanks for the reply, its got a coil pack. As I said in my last post changing the engine speed sensor sensor seems to have fixed the problem so far. Have had it back a week now and no sign of the problem.

Tahnks again.

Moz