DCI stuttering and cutting out

[sburrell93]

Title says it all really. Car had been stuttering a bit at around 1800rpm the other day under gentle acceleration, but this morning I left for work and it was a lot worse. Car cut out on me when pulling away from two separate junctions. Pedal to the floor and it just never done anything.

Feels like a fuelling issue more than a boost problem to me, but there's no warning lights showing up, and my EGR is unplugged anyway as it used to cause me problems, so that rules that out.

Anyone got any other ideas? Things to check?

I can run live data on the car but I don't know what I'd be looking for.

 

[MicKPM]

Fuel pressure is the first thing - 300bar minimum required to start then you should be looking at Fuel Pressure Requested vs Fuel Pressure Supplied.

I'm betting it's more boost related than fuelling at the minute as the car starts... it wouldn't do that if it were a fuel pressure/supply issue IMO

 

[sburrell93]

Fuel pressure is the first thing - 300bar minimum required to start then you should be looking at Fuel Pressure Requested vs Fuel Pressure Supplied.

I'm betting it's more boost related than fuelling at the minute as the car starts... it wouldn't do that if it were a fuel pressure/supply issue IMO

Yeah see it starts perfectly, just once running the problems appear. It does feel similar to when I had EGR problems to be fair, so boost related would make more sense. Will check the fuel pressures on it tonight if I get a chance though. Cheers!

 

[sburrell93]

Fuel pressure is the first thing - 300bar minimum required to start then you should be looking at Fuel Pressure Requested vs Fuel Pressure Supplied.

I'm betting it's more boost related than fuelling at the minute as the car starts... it wouldn't do that if it were a fuel pressure/supply issue IMO

Had a test last night. Car is hitting 400 bar on cranking and is pretty much spot on in terms of requested vs supplied rail pressures when driving so the fuel pump seems fine.

Typical though, couldn't replicate the problem when reading the live data. Feels more like a boost issue now I think about it now though. I'm thinking it could be the boost pressure solenoid.

 

[MicKPM]

Easy way to test that - Get yourself an old mechanical boost gauge and plug it in with a T piece. See if the vac crosses over and stays consistent