Z19DT Fuel Pressure Dropping

[eddyz1122]

I’ve never done one so can’t advise but if it’s easy to do it’s the first port of call as that small part does the controlling of the pressure bit. If the pump was gone it wouldn’t be able to make the higher pressures? Look out for relearning though.

Looks easy enough from when i was visually inspecting all the pipe work for leaks the other week. I had the same thoughts, that if it were the pump; it would never make the higher pressures even if you were to roll into it. But from the live data, it does make the full pressures when you ease into it, it lower gears anyway. Once you're into 4th gear it'll keep going without any issues.

I'm sure somebody else will chime in if I'm incorrect, but i don't believe you need to do any re-learning for a replacement Regulator on this engine. I do have the tools required to do it if necessary, ill have a poke about in the Fiat Diag software. That's if a genuine GM fuel filter doesn't cure it.

Thanks again for your input, its helpful to have somebody to bang heads with.

[eddyz1122]

Update: Genuine GM fuel filter did NOT resolve the issue unfortunately.

[northpole]

replace pump as this is one of the symptoms of a HPFP on it's way out... and while you are having to replace, you might want to decide to actually make it compatible so you don't have to tank premium fuel... the info is on the forum so have a look, it's not cheap though.

[troutybrown]

replace pump as this is one of the symptoms of a HPFP on it's way out... and while you are having to replace, you might want to decide to actually make it compatible so you don't have to tank premium fuel... the info is on the forum so have a look, it's not cheap though.

Are you on about the 2.2 petrol cos this thread is about a 1.9 8v diesel.

[northpole]

Are you on about the 2.2 petrol cos this thread is about a 1.9 8v diesel.

yes as i stupidly only looked at what engine he had in his profile... my bad

[eddyz1122]

yes as i stupidly only looked at what engine he had in his profile... my bad

No problem mate, I have actually replaced the pump on my 2.2 Direct unsurprisingly. It started failing at around 130k miles in 2021. Looked to have been replaced at least once before in the past, since there was witness marks on the bolts securing the pump and regulator. I fitted the pump you mentioned from Teamf5r that's compatible with E10. Had no issues since, although i do still continue to fill up with E5/Tesco Momentum.

[northpole]

Had no issues since, although i do still continue to fill up with E5/Tesco Momentum.

try the cheap E10 it'll safe you loads of money in the end, but the engine will run a little less smooth as it won't have the cleaners and octane boosters that the e5 has. Even if you did every other tank with e10 you'd be slowly recovering your investment in that fuelpump back.

Back ontopic after me making that mistake i did look it up: it's more common on the 3.0 cdti for the SCV to fail, but apparently they do, they also advise to remove the fuel pipes that come from the tank to the filter housing and blow them out with pressurized air back to the tank., as that will make sure the flow of fuel is not blocked by any debris. so i would replace the SCV you've already replaced the fuelfilter, but probably haven't blown out the fuelpipes.

[eddyz1122]

Hi All,

So it seems that im unable to reproduce the fault after changing fuel filter and changing from TotalEnergies Diesel to Tesco Diesel. Which im surprised about since i could immediately reproduce the fault after changing the fuel filter.