C70 starts when cold, runs for 10 mins then cuts out

[Dusty Miller]

C70 2005 convertible. Starts when cool/cold and runs for exactly 10 mins then cuts out. Thought it was a fuel problem so prior to taking to local garage replaced fuel pump relay, fuel pump, temp sensor and cleaned the MAF. Wasted effort but never mind. Then to local garage and their OBD revealed engine idle speed missing so replaced crank shaft sensor after which it started but cut out so cam shaft sensor replaced too. Thought that was problem solved but it just starts then cuts out after 10 and won't restart until cool. So at least it starts now!!! Local garage stumped, can do no more and reckon it's the ECU. Seems heat related. Could the ECU play up when the engine is warm? Well it's in that black plastic box and I can't see it getting that hot really but I don't know. I have yet to replace the fuel filter. Any ideas?

[turboboy]

It probably will not the fuel filter but it would be worth changing if you have done all the other work.

They are not hard to change. Did mine (and also the one on our VW Golf) earlier this year and only problem was neither had, to my knowledge, ever been changed and the V70's definitely looked like the original.

Years ago I had a Mk2 Jag which would start and run beautifully but sometimes stop for no apparent reason. Leaving it to stand for ten or so minutes seemed to cure it until next time. Once it did it on a narrow country road and I had to push it out of the way as I was blocking the road. Two very nice policemen helped me and I was sweating on them asking me about the car's MOT status (which was not up to date!).

Long story, short. It turned out to be a blocked fuel filter.

[David Gibbs]

Should be changed at least every three years dependant on usage also if tank often low in fuel the flacked inner paint and dirty petrol can cause the filter to block although it appears clean

This item is seldom covered by a garage at times of service

[Cookeh]

Fuel pump relays are a common match for these symptoms of hot starting issues.

[Simmy]

Originally Posted by Dusty Miller

C70 2005 convertible. Starts when cool/cold and runs for exactly 10 mins then cuts out. Thought it was a fuel problem so prior to taking to local garage replaced fuel pump relay, fuel pump, temp sensor and cleaned the MAF. Wasted effort but never mind. Then to local garage and their OBD revealed engine idle speed missing so replaced crank shaft sensor after which it started but cut out so cam shaft sensor replaced too. Thought that was problem solved but it just starts then cuts out after 10 and won't restart until cool. So at least it starts now!!! Local garage stumped, can do no more and reckon it's the ECU. Seems heat related. Could the ECU play up when the engine is warm? Well it's in that black plastic box and I can't see it getting that hot really but I don't know. I have yet to replace the fuel filter. Any ideas?

is your car a daily driver or an ocasional car? how old is the fuel in the tank? modern fuels dont store to well and leave deposits. also ethanol in current fuels have been known to affect rubber fuel lines this kind of problem also affects older motor cycles...

[C70 98]

Originally Posted by Dusty Miller

C70 2005 convertible. Starts when cool/cold and runs for exactly 10 mins then cuts out. Thought it was a fuel problem so prior to taking to local garage replaced fuel pump relay, fuel pump, temp sensor and cleaned the MAF. Wasted effort but never mind. Then to local garage and their OBD revealed engine idle speed missing so replaced crank shaft sensor after which it started but cut out so cam shaft sensor replaced too. Thought that was problem solved but it just starts then cuts out after 10 and won't restart until cool. So at least it starts now!!! Local garage stumped, can do no more and reckon it's the ECU. Seems heat related. Could the ECU play up when the engine is warm? Well it's in that black plastic box and I can't see it getting that hot really but I don't know. I have yet to replace the fuel filter. Any ideas?

I had that exact same thing happen to my -99 C70 T5 a few years ago, not even the local Volvo dealership knew what it could be. Started fine when cold, drove fine until up to temperature, started jerking and eventually cutting out, all warning lights lit up and it either started straight again and cut out half a mile later, or then didnt start at all before cold again. As said, not even the local dealership knew why. What, probably, did the trick though, was to take the ECU out and put it back in a couple of times, after that it worked as normal again.
Must have been a bad connection or something that somehow sorted itself out just by taking the ECU out, possibly moist gotten inside the box, I replaced the lid on it and the car has been working ever since.