So hopefully this is the right spot to ask this question. Here is the situation, we have a '95 K2500 with a 5L motor and automatic I believe it should be a 4L80e? Anyway been running great for years, then one day after taking it up to the house it won't start. So we did some obvious troubleshooting
a) Checked to hear fuel pump, we hear it
b) Checked fuel pressure at engine, 15psi and pump/filter was changed recently
c) pour some fuel down the throat and it fires right up and runs.
d) Checked wiring around ignition control module, and various grounds
e) added more grounds to block and body just in case
Still nothing. Because it runs when we pour fuel down the throat that kindof suggests ignition/spark etc is all working fine, just the injectors are not spraying fuel for some reason. We swapped the ignition control module from a parts truck anyway since i believe it sends the signal to the computer to tell it to pulse the injectors? Maybe? Not totally sure but either way no change with the replaced ICM. While I wasn't around, my father-in-law took the ECM from the parts truck which I believe is a 1994 C1500 with 5.7L Automatic so a completely different drivetrain and put it in the 5.0L 4x4 and tried to start it, it backfired pretty bad. Anyway to me that's a bit of a clue, a backfire would suggest the injectors were firing and it had way too much fuel... not sure what the fuel mapping is like between a 5L and 5.7L but even whatever put the old ECM back in and again nothing happens.
So... I'm beginning to suspect the ECM is having issues for whatever reason, I took it out and looked and it's a 16197427 with the part number BJXL
I went to the wreckers and of course they have nothing with a 5L in it, closest I could find is a 16197427 with BJYL which I believe is a 1995 5.7L K1500 automatic... so close but wrong engine size.
So my question is, can I take a wreckers 16197427 with the BJYL EPROM and reprogram it to be a BJXL? And if so... how? And where could I find a .bin for a BJXL so far I haven't been able to find one anywhere for downloading.
OR... if anyone has any suggestions to try I'm all ears! Maybe it's not the ECM at all but I'm stumped why those injectors are not firing