Loosing rail pressure, but not always?

Woolf

New member
Jan 9, 2012
3
0
0
I'm running a 2010 LMM with the PPE on Level 3. For some reason the first time I get on it it seems to drain rail pressure but only before the 3-4 shift. I thought at first it was the tranny, but it really seems like it is just losing fuel really bad and when it shifts, it is back to normal. Happens around 2800 rpms - shift. Crazy part is it only does it on the first run. If I were to run consecutive runs, everyone after the 1st would be fine. I tried to monitor on my PPE, but that was really tough. I did not see a dip in psi delivered though. Hot or cold, it seems to act the same. Anyone have any ideas? Do I need a lift pump? Would EFIlive fix this? Is my fuel filter just dirty, it's only about 1000 miles old?
 

Bonestock

Active member
Aug 9, 2010
1,358
1
38
Worland Wy
You shouldnt need a lift pump in level 3 but if you can monitor desired rail vs actual rail it will tell you for sure. you will need someone with a v2 EFI Live to perform this unless you have another way of doing it. Good Luck.
 

LWATSON

future trans limpers
Jul 30, 2008
2,587
1
36
55
Scotland Neck NC
When I had PPE on my truck it felt like power fell off in third gear and picked back up in fourth. I think it was torque management or the converter unlocking.
 

Dozerboy

Well-known member
Jun 23, 2009
4,892
470
83
TX of course
You "need" a lift pump. My truck did that like clock work on the first WOT run even on smaller tunes. I can't say for 100% that a lift pump fixed it, but I haven't seen it on any logs since.