MK7 2.2 FWD T350 Rising fuel pressure ?

[Huxley]

Anyone experienced a similar issue?

Current problem with my 150,000 miles transit MK7 2.2 FWD T350 Rising fuel pressure.

Vehicle starts ok but will intermittently run rough and not rev! Every time this happens my digital 'miles to empty' display flashes with four flat lines (----) and sometimes the cog warning light comes on. However no fault code is stored !

When a laptop is plugged into the OBD I can see using live data that the fuel rail pressure, while the above symptoms are happening, rises off the scale until you accelerate at which point the pressure drops dramatically (if it revs) and the digital display returns to normal.

Any ideas? The problem I have is this is not all the time and will drive for a hundred miles and be fine then will play up.... Its dangerous!

Thanks for your time, I will change the PRV tomorrow as a precaution!

[Huxley]

Added info!

57 plate 2008 vehicle.

On tick over the fuel rail pressure should be 23MPA, however when the fault happens on tick over watching the live data via laptop it rises to 90MPA, then when you rev it drops to 23MPA.... Stop revving then it rises again! Every time this fault occurs then the digital 'miles to empty' display changes from digits to ---- and flashes, sometimes the orange cog light illuminates also.

Annoyingly sometimes it wont rev either and I have to stop and restart the vehicle.

I am changing the PRV and pressure sensor in rail later today. The Fuel Metering Valve and Pump Learn was done last Thursday!

I will also be volt dropping the battery, vehicle and engine earths today to check all is ok there.

Really interested to know if anyone has these issues currently and like me are scratching there heads or if indeed have had these issues and have successfully repaired it permanently.

Thanks

[Huxley]

Todays update!

Removed PRV which was in pieces, replaced with new ford part. Made no difference sadly but at least it needed replacing.

Went to local ford van centre and spoke to a 'mastertech' whom advised van probably needs a software update. I have booked in for Friday morning at Ford and will have the software update done anyway as it may help to compensate with any ware on the engine, I am not confident this will cure the fault tho the 'mastertech' seemed sure.

I had also spoken to another transit guru that suggested the problem is more likely with the body control module or at least a fault between the ECU and BCM, either wiring chaffed or plug loose to the BCM. Had a quick look tho nothing obvious.

This is frustrating to say the least....

[Back probe]

Strange one, I would of expected this fault to have been cured by the parts you've had replaced. I'd be surprised if a PCM update fixes this, or if it's BCM fault. Might be worth checking the readings at the fuel rail pressure sensor with a meter.

[Jim Archer]

Reckon you want to be looking at the inlet metering side of things, seeing as that is what normally governs the rail pressure.

Jim

[knobby1]

What Jim said...

If you're PRV was in pieces, it will probably be a faulty SCV which has caused it, just replacing the PRV probably won't help much....best to replace both valves and do all the relevant learns. Always use genuine Ford items too, we've had all sorts of grief using non-genuine ones, some work some don't.

Lord Knobrot

[Huxley]

UPDATE !!

Vehicle has been fixed yehaaa.....

Please bare in mind at no stage during the the fault finding process did this fault register at all with the (EML) Engine Management diagnostic fault code readings etc In fact the EML was never illuminated apart from when ignition is switched on!.....Defo one to look out for.

Yesterday the fault was traced to the crank shaft sensor which was smashed to pieces ! With the help of another mechanic we was messing about with the loom from ECU to engine to which when moved and jiggled around made the fault appear and disappear. We stripped the loom to thoroughly check all the wires but found no breaks or chaffing etc.... And then there it was, branching off the loom, beside gearbox housing is the wiring that reaches up over the gearbox to the crankshaft sensor, as we pulled it we actually felt the Crank sensor move! Grrrrrrrr....... The sensor just pulled out freely from its location, the plastic moulded bracket attached to the sensor to which the bolt goes through to retain it in the bell housing was broken and not present, neither was the bolt. The guide/location bracket inside the bell housing was also broken! The end of the crank sensor was chewed/smashed back to the magnet sensor. I'm amazed it ran at all to be perfectly honest.

The Fix..... (thinking outside the box)
New crank sensor from euro car parts £26
So the fix would have meant removing the gearbox to fit a new location bracket which the bolt goes into from the new sensor.
I really didn't have time for this now as this fault has been meant my truck has been off the road for a few weeks.

Using two brass washers we trimmed them down with an angle grinder to mirror image the base shape of the sensor, this allowed the sensor to seat correctly and space it accordingly, Now to secure it without it popping out or turning around!

For this we used a soldering iron to indent/mark approximately 1/4" all the way round of the hard plastic shaft of the crank sensor of where it passed through the bell housing thick metal, thus changing it from of smooth slippy surface to a knobbly golf ball rough like surface.

Pushing this home it felt very tight and secure. We then set about tapping up the loom and fitting a new bracket to the gearbox to simply secure/cable tie the loom thus minimising movement to the sensor loom etc.

Boxing the vehicle up we then started it. On the button, no flashing (----) miles to empty display, No fuelling issues on live data, revs perfectly with no faults stored at all on the ECU....

Took it for a road test which involved me going for bumps, pot holes, drains etc in the road and it drove perfectly for the duration of the 15 min test. However the big test is today as I will be travelling 200 miles but tbh I know the problem is fixed due to the severity of the sensor. I will report on my road trip later.

Really hope this helps others in the future.... Goodluck fellow transit owners

[Huxley]

450 miles travelled over last two days in my transit and it has not skipped a beat. My van feels reliable again!

[wronghole]

Made interesting reading .glad its sorted

[Huxley]

Made interesting reading .glad its sorted

Thanks mate.
Yes very odd situation I think. Im sure this thread will be of use to other owners in the future!