All,
A buddy dropped his truck off, having some issues, where after driving for ~8 minutes, it will sputter and kill (lean shutdown). If you try to start it immediately, it will fire, run for only a few seconds and kill. If however, you let it sit for a bit, fire it back up, it will run for another 5-8min.
Its a factory 5.3l, swapped into a jeep. I'm fully aware of all sorts of potential issues that could be lurking, but the fact is, he hasn't had this problem in the 3 years the build has been functioning.
So, I hooked up, took a scan while we drove it around, from cold -- and 8 minutes later, it dies. I then recorded another short scan, after we restarted it.
When looking at the data, it appears that towards its lean stall, you can see the EQ CMD goes from 1.0 to infinity very rapidly, simultaneously, the injector pulse width goes from 3.0 to 10+, and the STITs from 2.5 to zero..
I've done the following to rule out some potential concerns -- we did this on the trail...
1) replaced fuel pump
2) verified fuel pressure
3) replaced fuel pressure regulator to be sure (known good one)
4) replaced cam and crank sensors with known good ones
I'm wondering why it is killin itself.. and kinda stumped.
Attachment 122576
Attachment 122577
Attachment 122578
Thoughts?
Thanks,
Jason
