So, I am newly signed up on here, but have been a lurker for a few years and have had some great info, so many thanks for that!
A few months back I bought a 04 TD4 with a known fault. The seller said it was a poor starter and had been for years. When runs it sounds and pulls fine, but it takes quite a bit of cranking and eventually fires upon a couple and then picks up on all 4,blows a bit of white unburnt fuel smoke and then will be fine, until next time you come to start it. Almost like its losing fuel from the system and takes the cranking to re-prime.
My code reader tells me there are no codes stored, but sadly doesnt give me fuel pressures.
Rear LP pump and filter changed
Wiring to HP pressure sensor sorted
Initially a replacement o ring on the FPR, and then a brand new FPR as I convinced myself this was the issue. On the sense pin of the HP FP sensor I have about 0.5v at ign on, 1.25v idle, but 3V at 3k rpm, this led me to the fpr, but no different now changed.
I did a leak off test on the injectors too, and although not brilliant, by no means did I suspect this was the issue, none of them are chucking out loads of fuel and more or less the same. I have had number one injector out as needed one for my wife's car as one of hers was really heavily leaking off. Subsequently stripped and cleaned this in an ultrasonic bath and put it in mine and this injector is the one now with least leak off. Incidentally, I should add that her's started fine even with this injector in, but ran quite lumpy, the nozzle was down to about 2 and a bit jets when tested before cleaning.
Would welcome any suggestions or what to look at next. I do have a scope and know how to use it, I should also mention I have scoped the feed to the FPR and that looks fine. The 3v at 3000rpm is now making me feel I may have a problem with the HP pump, I hope not. I can see it has been replaced at some point already, but not recently. Also note that it has had a new starter at some point in its life,probably down to the long term fault requiring lots of cranking.
A few months back I bought a 04 TD4 with a known fault. The seller said it was a poor starter and had been for years. When runs it sounds and pulls fine, but it takes quite a bit of cranking and eventually fires upon a couple and then picks up on all 4,blows a bit of white unburnt fuel smoke and then will be fine, until next time you come to start it. Almost like its losing fuel from the system and takes the cranking to re-prime.
My code reader tells me there are no codes stored, but sadly doesnt give me fuel pressures.
Rear LP pump and filter changed
Wiring to HP pressure sensor sorted
Initially a replacement o ring on the FPR, and then a brand new FPR as I convinced myself this was the issue. On the sense pin of the HP FP sensor I have about 0.5v at ign on, 1.25v idle, but 3V at 3k rpm, this led me to the fpr, but no different now changed.
I did a leak off test on the injectors too, and although not brilliant, by no means did I suspect this was the issue, none of them are chucking out loads of fuel and more or less the same. I have had number one injector out as needed one for my wife's car as one of hers was really heavily leaking off. Subsequently stripped and cleaned this in an ultrasonic bath and put it in mine and this injector is the one now with least leak off. Incidentally, I should add that her's started fine even with this injector in, but ran quite lumpy, the nozzle was down to about 2 and a bit jets when tested before cleaning.
Would welcome any suggestions or what to look at next. I do have a scope and know how to use it, I should also mention I have scoped the feed to the FPR and that looks fine. The 3v at 3000rpm is now making me feel I may have a problem with the HP pump, I hope not. I can see it has been replaced at some point already, but not recently. Also note that it has had a new starter at some point in its life,probably down to the long term fault requiring lots of cranking.
