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Hi, I'm wondering if anyone on here could help me, we have a
2012 Peugeot expert
2.0 turbo diesel in at work.
A brief history of the van
We bought this van from a auction before we road tested the van I serviced it and changed the cam belt. Then when I test drove it the van surged and slowed as if I was pumping the throttle pedal.
After some investigation I found the van had a new turbo fitted and the travel stop bolt on the waste gate was not allowing the actuator to open fully and the pcm was bringing up a fault code about the actuator performance. I adjusted the travel stop and re tested the van. All seemed ok apart from the van seems too fast if that makes sense? As though it's over boosting but my numbers on the scanners are suggesting the boost pressure is fine.
My boss then used the van for a night only for the management light to come back on, this time it was a low fuel pressure fault code and we now realise that the low fuel pressure is occurring at low rpm (around 1500) when the throttle is fully open.
I changed the pressure control valve as we had one lying around but the van still has the same problem. We also changed the fuel filter again as a precaution but the problem is still there.
When the van is revving the actual pressure is always close to the desired, which has left me thinking of 2 possible causes.
1, if the new turbo fitted is the wrong one and the maf is seeing more airflow than usual could the pcm ask for more fuel pressure than the pump can deliver at low rpm?
2, maby the fuel pump is weak and this is the cause? Am I right in thinking I could use my test light to close the pressure control valve and see on the scanner what the fuel pump is capable of delivering at low rpm? Or is this a bad idea?
Sorry for such a long message I just wanted to give you the whole story thanks in advance for any help. And also thanks to Paul Danner for taking the time to do all the great videos and the book they've taught me a hell of a lot
Cheers
Ian
Hi do you have the exact fault code for fuel pressure?, if the pressure control valve is ground side controlled, you can raise the revs to 2k then ground the control side forcing the pcv closed and maximum pressure to be held in the fuel rail, the engine will cut out, do this with a fuel pressure gauge attached or even a volt meter to your fuel pressure sensor signal wire, keep the pcv forced closed, this will not hurt anything, watch your fuel pressure from start to finish, as soon as you close the pcv the pressure will rise but the important thing is to watch when it reaches its maximum point it should stay there until you release the pcv, this is a proof test, and will test the integrity of the system to hold its pressure and is also a great way to see the performance of the high pressure pump itself, if it's not holding pressure you have a leak, possible internal or external, look for leaks, if you don't see any chances are it's internal, you can block supply to each injector one at a time too rule them out.
You will also need to check the low pressure side if this has an in tank pump, this will involve an inline gauge to verify low pressure side
As for turbo, it's it variable vein type or wastegate?, if variable check to see that it takes roughly 18 inches of vacuum to fully open them, if wastegate check to see preload is correct
