Irregular cutting out

[Alex O]

Hi Guys,

I have a strange and very frustrating issue

Recently my Gen3 3.0 surf has just cut out. It's as if you turn the key - no lights appear on the dash and it will start right back up again....run for a few minutes and die again.

It will either do it for ages, half an hour or so, or it'll be fine immediately.

First event was on a Sunday and then was fine for a week. Then did it on the following Wednesday. We changed the clogged fuel filter and all was fine for about 5 days then it happened again.

It's now with a mechanic and refuses to break down, leaving him scratching his head.

Any common issues? Fuel shut off solenoid or ignition problems to look for?

Really appreciate any help, aside from this it has covered 10,000 fault free miles in the last 3 months.

Thanks
Alex

[Dobbslc]

I would check very carefully for an old imobilizer, even if you don't have a fob for it. They can cause loads of grief.
Fuel pump relay or any other main system relays. Worth checking the ignition switch too.
Dobbs

[Alex O]

Hi mate, I had just thought of immobiliser, so thanks. It's one with a passive key fob and I guess they can fail?

Thanks for the other suggestions, will check...

Alex

[arh]

If it keeps doing it have your ecu checked out, the ecu doctor doesn't charge you if it's good. Mine did this for a while then it stopped completely. check out the thread, "help wont start", (well, one of them, lol), best of luck, arh.

[Alex O]

Ok, I have blanked off the ECG valve and removed some electrical circuit box in a box from under the drivers seat....(any idea what this could have been?)

Will see if it happens again....

[Koi]

does it only do it while at idle, full throttle or when coming to a stop with foot off the gas?

[Alex O]

It only does it either on idle or when coming back on the gas after braking/coasting....

Does this give you a clue?

[Koi]

was gonna say EGR or possible blocked breather causing vacuum in the tank. My 2.4 had similar, was fine under load but at idle it cut out. Was simply a blocked breather pipe.

[Alex O]

OK - we blocked disconnected the EGR and plugged the vacuum pipe. This did not help but instead the truck held gears for longer and shuddered quite a bit when you turned it off.

There are little electrical boxes under both the drivers and passengers seats that plug into a loom. Does anyone know what these are? I have unplugged the drivers side and it seems to make no difference.

As previously mentioned, there is an imobiliser fitted but seemingly disconnected. I suspect this could be the cause and I am having this removed and replaced with new alarm/immobiliser tomorrow morning....fingers crossed this helps.

Koi - how did you test the breather pipes to determine where the blockage was?

Thanks, Alex

[charvell]

the box under the drivers seat is for the central locking. Have you changed the fuel filter and tested the primer?

[Alex O]

Thanks, worked out what the box under the seat was.

Fuel filter changed and primer is ok too.

Had the old immobiliser removed and a new alarm/immobiliser fitted this morning. Don't think this will help but has been fine since.

Next step is to run with the fuel cap off for a bit if it does it again to determine if the fuel breather pipe is blocked.....

Will report back...

[Alex O]

Update:
New alarm is great but solved nothing.

Fuel tank breathers are not blocked.

Worked out that if I disconnect the batteries then it's fine for about 3 days before cutting out recommences. This lead me to believe it an electively problem.

Took the ECU out and two of the capacitors have leaked onto the circuit board (hope it's not tooooo serious). Send ecu off to the ecu doctor this morning - fingers crossed I may have got to the cause.

Worth mentioning that when it cuts out a relay clicks from the passenger side. Once or twice the relay has clicked again and caught the engine before it fully died and allowed it to start running again.....

Once I hear from the doctor and refit the ecu I shall update again

[arh]

as I said in the beginning, that is what happened to me, it was the ecu. always get it checked first and save yourselves a lot of problems, if it's good he'll tell you for nowt! but the cost of posting it to him.

[Alex O]

Yes, you are hopefully going to be proved right.

Hindsight is a wonderful thing and I wish I had looked at the ECU first rather than prioritise other options.....oh well.

I'll come back to confirm in due course...

Thanks mate
Alex

[arh]

I apologise, I was wrong, the doctor charges £35 to check an ecu, but it's knocked off the bill if it's faulty, and that's good value to know that the ecu's not at fault. Though he doesn't charge if he cannot test it.