Thread: 2.7 tdv6 won't go after fuel system repair

Originally Posted by josh.huber

The one that stands out to me is. Fuel pump control circuit high.. Which will hold back your rail pressure

But what causes that, could have been when I pulled the LPFP fuse and jumped it?

Yeah my bad, I was thinking about the HPFP circuit not the LPFP circuit. It's the rail pressure rising at all when cranking

Originally Posted by josh.huber

Yeah my bad, I was thinking about the HPFP circuit not the LPFP circuit. It's the rail pressure rising at all when cranking

Not not really, won't go above 130kpa.

Originally Posted by shack

Not not really, won't go above 130kpa.

Has something gone wrong with the belt change. Is the HP pump being driven correctly? Been years since I did mine.. Can't remember much about it. Slipping drive?

Originally Posted by josh.huber

Has something gone wrong with the belt change. Is the HP pump being driven correctly? Been years since I did mine.. Can't remember much about it. Slipping drive?

It happened before I changed the belt, that's the reason I did the belt, I was wondering if it snapped, it was well overdue. Highly unlikely it's the belt.

Many moons ago my car was faulting very randomly, thing the basics of the fault was low fuel rail pressure. Eventually decided it was HPFP , I had a low km spare that was working when removed and I got a local indy to do the swap for me as I was away working. I got a call to say he fitted the pump and the car wouldn't start, he didn't do to much fault finding and basically said I needed a new HPFP which I went ahead and got done and it has been going well ever since.
Not sure if yours is the same or even what the faults that he had show up but I'm guessing there was something in the pump or its workings that causes it not to start.
Bulletman

When I was fault finding the HPFP in mine I "exercised" the valves with a 12V SLA battery in series with a 21W bulb. The car started and ran with the PCV fully closed but the rail pressure was sky high and it made a lot of noise. I wouldn't recommend it, but I did it because the valve was getting stuck and the PWM signal from the ECU never really exceeds %50, and there wasn't enough of a "jolt" to unstick it.

You could also try repeatedly knocking/shocking both valves with a screwdriver, although getting to the VCV is a "bit of a challenge" with the pump in place.

I'll see what I can do.

I think a large part of the problem in diagnosing it is the blurring of the details by it happening after work on the fuel system, causing me to think I did something wrong, when in fact something may have failed simultaneously.

If it had stopped on the road I would have gone about it differently.

It's just so hard to get to things to check just on a "whim".

Maybe one of the 2 valves mentioned snapped open or shut because It ran out of fuel not being bleed properly, and now it is stuck?

Cheers
James