P38A 2001 THOR V8 INJECTOR PROBLEM

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PastyMuncher83

Active Member
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249
Location
South Somerset
How do all, i have been busy trying to sort an ongoing problem I've been having on my thor 4.0 P38, but am out of ideas...

Basically it was running rough on petrol but ran fine on LPG. Reading EMS codes using a Hawkeye kept getting the same fault code come up-

Fault 151 - P0265 - injector cyl 2 power stage maximum value exceeded.

So basically in an effort to sort this, as well as attending to a few other jobs whilst i had the upper manifold off, i did the following.

Inspected wiring harness, all seemed ok visually.
Tried testing the loom for continuity to each injector from the relevant fusebox location, but couldn't get any continuity on any of the injector wires. (Electrics is not my strong point)!
Tested resistance of all 8 injectors, all read pretty much the same.
Bought a second hand fuel rail with gauranteed working injectors, cleaned them all, replaced the lower O-rings and pittle caps and fitted to the engine.

Put it all back together and still getting the same code!

Any suggestions as what to try next? Same as before as soon as the truck switches to Gas i get all 8 but on petrol seems that Cyl 2 is just not firing.

Any help gratefully appreciated!
 
Sounds like a connector issue, but I'm hopeless with leccy too.

Lpg injectors are fired using petrol injector signals so all seem fine on that score.

I'd test for continuity between petrol injector connector pins and the loom.


That's the most simple thing you can do with a meter, after switching it on, although I usually find a dead battery in mine, little that I dare to use it.
 
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One of the petrol injector wires are cut and this goes to the lpg ecu then another wire goes back to the other side and on to the petrol injector. This cuts the petrol injectors and allows them to work again.
Often these are very badly soldered and you could check those connections. Continuity from both ECUs to the injector. I suggest trying to find out exactly what your code means" power stage maximum value exceeded" i i believe this is 5 series BMW management system so you could try those forums.
 
Ai simple enough even for me! I couldn't get any continuity from the ecm back to the fuse box and then same from the fuse box to any of the injector wires.

Fuse box was brand new LR part about a year ago. Looks like i'm gonna have to whip the manifold off again :/

I was tempted to join a wire from the yellow no 2 injector connector then to the appropriate wire from the engine ECM, in the thinking when the ECM fired a signal to fire that injector it would ensure it got there! Or does that sound to Wallace and Grommit..

Interesting you should say about the injector signals because...when i first bought the car the LPG wasn't working. The garage i bought it from had just had it apart to change the head gaskets. After much head scratching it turned out they had cut all the LPG injector signal wires and looped them together to enable the petrol injectors to fire. One new LPG ecu and vaporiser later...
I had the LPG wizard Graham at Causeway 4x4 in Bridgwater, can't recommend the guy enough, work out which pair of wires had to go with which pair of wires, (40 wires, 20 purple, 20 orange), and it ran perfect since then.

Once i got this injector problem my first port of call was checking these connections, which i took apart and re-attached but made no difference.
 
P0265 seems to mean that injector circuit is drawing to much current which to me suggests a short if there's no issue with the injectors. Your trials with the injectors may be the key to this as it seems like it's been messed around with leading to potential problems due to dodgy insulation.
 
The injector wires will both terminate at the ecu but I'm really not familiar with the Thor system. Perhaps take it to your lpg guy.
 
All you need to focus on is that one injector. Find the cut where the lpg wires go to the lpg ecu. Usually these are done with solder and a bit of insulation tape. They get really hot and just fall off or crack.
 
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