strange electrical problems with a 1989 4x4 surb

[kerjohns]

Hi guys,
I am back with more questions. The truck is a 1989 4x4 surburban, v1500, with a 350. Have replaced the ECM, Throttle position sensor, Map sensor, fuel pump relay, the fuel pump guage works good. But still keep getting an error code of 32 from the oil pressure, the truck willl start and run, and then suddenly it will die for no reason at all-then after a 10 to 15 min wait I can restart it and it will run good for awhile longer. Any ideas or help is welcome. I am in Arizona at my sisters house and we are trying to get this beast rdy for the trip back to oklahoma.
Thanks for any help with this,
Kevin

 

[3 on the tree]

I would unhook the wire from the oil pressure sensor and see what happens. W/O a wiring diagram, its hard for me to troubleshoot. If it were mine, and it will not run with the wire unhooked, I would ground that wire next, and see if it keeps running. Dumb question-is the oil pressure good?????

 

[kerjohns]

oil pressure is good but the gauge will tack past 60 sometimes when accelerating and wont at others. when the gauge is malfunctioning is when it die's (relay cuts fuel) when I disconect the oil sensor it will still run, but seems to have the same problem(fuel relay cuts off). When it dies I wait about 10-15 minutes and then it will start back up,either by itself or by swapping to a different fuel relay.
Also it is not having the error 32 code it was bought about 4 months ago and we were looking through the paperwork in the glove box and found that it had the ECM replaced about 8 months ago and from the work order it looks like the guy was having the same problem.