Issues with stalling and fuel rail pressure

Dante2795

Member
Aug 19, 2017
64
1
8
Having issues with my lbz racetruck. 200s, dual pumps and single 76. When I rev it up, it surges then stalls out. In P, N or D. Just replaced filters and drained tank and put fresh diesel in. Still the same issue. Unplug either fpr and it stalls out instantly. Anyone ever run into this?
 

Dante2795

Member
Aug 19, 2017
64
1
8
Are you losing fuel pressure somewhere? Have an injector return a bunch of fuel?
Just logged it and when I unplug the fpr, actual and desired both max out together at 29k and then it stalls out. So it’s not losing rail. Even if I unplug the rail pressure sensor it stalls out. For whatever reason when it sees high rail pressure the trucks stalling out
 

ZeroGravity58

Well-known member
Mar 23, 2008
1,375
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Maryland
I haven't done it for awhile but if I remember right when you unplug the fpr the desired fuel pressure shouldnt change, it should just max out the actual fuel pressure.
 

Dante2795

Member
Aug 19, 2017
64
1
8
My race truck randomly started stalling and surging. When I give it some throttle it idles like it’s about stall, then surges then dies down if I get on throttle heavy. If I ease into it, I can get to about 2200rpms before it starts hesitating.
So I unhooked fpr and DESIRED maxes out with Actual to 29k then the truck stalls out. But I plug it back in and the truck will start right up

I’ve never seen desired max out before. I also unplugged fuel rail pressure sensor and that stalls the truck out too. Replaced the sensor, same thing.

Any ideas?! Fresh fuel, fresh filters. I’ve logged it and don’t see anything that catches my attention besides the desired rail pressure

this all started happening when I flashed in another tune I ran in the truck before Hand so I know the tunes fine
 

2004LB7

Well-known member
Dec 15, 2010
6,282
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Norcal
I think we need to get some logs here. What mm3 is commanded when the fpr is unplugged. RPM, fuel pressure, PW, and any other relevant pids to see if it is tuning related or hard parts. Otherwise we are just guessing