I am at loss with my 2002 LB7. 255K Sac injectors, fass lift pump, EFI Live. I have no codes thrown. The other day got about 3 miles away truck killed at stop sign. Started up in neutral idled it for sec dropped into gear dies. After multiple try's was able to tranny drop it a bit to get it to go. Ran fine while cruising but when slow to stop signs it would try to die so gave it a rolling stop. Finally got it back home died in the driveway. This time couldn't get it to start. I let sit for an hour and it fired right up, and I pulled it into the garage. I looked for any wires that may have been chewed on by mice with nothing I could see. Today I changed the filters on my lift pump. Truck ran idling for 10 mins before dying. Didn't want to start after a few mins I was able to get it to fire. Reved it north of 1k rpm no issues for a few mins. let it under 1k rpm died. Got it started again revved it let it idle, ran for the next 23 mins. I turned it off. Tried to restart and didn't want to start. Gave it like 15 mins and truck started and idled for another 15 mins. So I'm not sure where to go next with this. Is it fuel or electrical? Any help one which direction to go would be much appreciated.
Don't know where to go
- Thread starter Big_Mel
- Start date
Do you have a scanner that will show desired vs actual fuel rail pressure. Make sure your lift pump is actually working. If it is it could be you high pressure pump. It could also be your fuel pressure regulator sticking open, then as it sits slowly closing.
in addition to the above, it would be a good idea to do a return rate test on your CP3 and maybe even the injectors but because you already upgraded to SAC style it's unlikely to be them. you may have a weak or failing CP3 or a restriction in the fuel line or your lift pump is not doing it's job right. I wouldn't rule out large amount of air getting in the lines too. that can be checked with a clear line in place of the original