Hello again all,
Have'nt been here for a few months, just to recap I have a 95 xj 12, Daimler.
I have a fuel problem with the car, it starts when cold then dies after 10-12 minutes, runs rough then stops. Fuel pumps are changed, has spark & fuel, plugs are clean, I am in UAE so its not easy to get specialist help here.
1. Any ideas what the cause may be...?
2. Anyone know the Dubai area where I might get a mechanic or parts.
Thanks all,
Best regards,
Harry

 

Harry,

Those V12's were rare in any market, and you are probably the only one in those parts.

The running time prior to failure makes electrical sensors really not part of the equation in my opinion.

I am thinking along the lines of fuel starvation.

Remove the gas cap, and see if anything changes, it may as simple as the tank is not breathing as it should. That is NOT a common issue with "in tank" pump vehicles, but it can happen. Some GM vehicles down here suffer from it at times.

 

Then what happens? Does it re-start OK or ???

Any black smoke?

One possibility might be the coolant temp sensor. If the sensor was stuck "full cold" the engine would start and run properly for a few minutes but a warmed-up engine...as it would certainly be after 10 minutes... would not tolerate the over-rich mixture.

<shrug>

Just a thought, and one of the easier possibilities.

Cheers
DD

 

Thanks Doug,
It wont start until cold again, some black smoke before it cuts out, maybe the CTS but i have no diagnostic tools here.
Thanks,
Harry

 

OK thanks for your advice, I thought of this when the problem originated, but no change.
Regards,
Harry

 

hi. how about fuel pressure regulator?
Or maybe an idle control valve?

 

Still sounds like the CTS-black smoke before the engine cuts out is a sign of a rich mixture.

The CTS usually has a high resistance (several kilohms) when cold, which falls to quite a low resistance (a few hundred ohms) when hot.

If the resistance stays high (faulty sensor or poor connection somewhere), then the ECU will think the engine is still cold & keep the mixture rich. Once you get past a certain point in the engine warm-up cycle, the excessively rich mixture will then make the engine stumble & produce black smoke before it cuts out.

It's definately giving all the classic symptoms of a failed Coolant Temperature Sensor-however, it could be either the sensor or the connecting wires. If the wire connection is corroded or broken, it will give the same high resistance signal to the ECU-which will then richen the mixture & cause the engine to falter as it warms up...

 

Hi I had the same problem on another car and I found that it was a split in fuel pipe it was only small ran fine on cold then used to judder and cut out and wouldn't start up again so check all your fuel pipes and whilst its running to see if you can see a leak

 

interesting...

 

Very.