V6 - starts but dies after 5-6 minutes

[onehillside]

More issues this end.

V6 petrol.

Starts on the button, holds steady revs at idle, revs freely, drives fine and sounds smooth. Then after 5 to 6 minutes she dies. And then refuses to catch / start. If I leave her and go back after an hour she starts fine again and then dies in turn.

I have changed the fuel filter. There's plenty of fresh petrol in her tank.

Slightly stumped and wondered whether anyone has any ideas before I have to turn to the garage (and start racking up the ££). I had thought it might be fuel related - could it be the fuel pump? I'd have thought the fact she starts and runs fine, all be it for a short period, kind of puts paid to that. The alternatives are?


Any ideas gratefully received...

[jimmo62]

Could be a blocked fuel tank breather - which allows air into the tank as the fuel flows out. Try running with the fuel cap off (having taken suitable precautions of course) - if OK then you'll need to work out where the breather is and see if it's clear.

[jimmo62]

Also worth checking you still have a spark at the distributor in case it's an HT related problem, can't quite think why it would come on after 5 mins but perhaps temp related?

Also try seeing if there is a fault code on the engine computer, it could be detecting a problem and shutting down the engine. You can read the fault code at the diagnostic socket with a voltmeter, should be something on the forun on how to read it and what the codes mean, if not let me know and I will dig out the website details.

[Northern Bongolow]

not having owned an inferior petrol bongo sounds like the cold start system is faulty.
if its owt like the diesel it may have a 2 stage cold start system, as the motor starts it activates full cold start, then after about 10-30 seconds depending on ambient temps it may drop down to half [choke], until it warms up fully then it goes full off. it sounds like yours is not working correctly.
it maybe the engine temp sensor [not the gauge sensor]. or the building choke that acts on the throttle peddle. there is also the oxygen sensor

these may help you a little.

http://lushprojects.com/bongopartsmk2/c ... mgno=.html.

http://lushprojects.com/bongopartsmk2/c ... mgno=.html.

18-840c on this is the temp sensor.
http://lushprojects.com/bongopartsmk2/c ... o=.html#11.

if you click on the numbers on the sheet it highlights what it is on the left hand margin to help with part numbers.

[onehillside]

magic folks - thanks for the suggestions - will try tomorrow!

thanks

[Simon Jones]

Does the problem only happen when idling or does it occur when driving? If it dies while driving then it seems less likely to be anything cold start related.

You need to see if there is a still a spark. If not, I would be looking at the crank position sensor which can fail when they get warm or wet.

[windywatson]

Hi, no 2 stage cold start systems on the highly superior petrol V6. I have known ignition coils fail once hot. I had exactly the same symptoms on a cavalier years ago, new coil sorted it. As suggested the thing to do is some basic tests the moment it cuts and won't start pull off the ignition lead from the coil and get someone to crank it whilst holding the lead end towards the block or chassis and see if you can get a spark to jump the gap. In years paste I also suffered the same symptoms with a Renault I had and that was a failing electric fuel pump failing once it warmed up. Found that by pulling off a fuel line in the engine bay when it cut out and turning on the ignition and watching for fuel to flow.