Random engine dies
06-12-2017, 03:56 AM
#1
Random engine dies 2003 sierra 4x4
Just as above I'm needing some serious help.
Parts now new and still randomly dies either at speed or at idle.
Alternator, battery, throttle body, fuel pump, fuel pressure regulator (will install in 3 hours delivered yesterday), engine, transmission, all grounds are good I've check this multiple times, transmission neutral safety switch/gear selector, 4x4 actuator/selector (on top of trans), ignition coils, spark plugs, under hood fuse panel and fuses, starter. I've thrown thousands into this thing and nothing has fixed this issue. Dies at random but starts up after a few seconds without any issues.
Other odd things, sometimes dash light on display show odd symbols after key removed, sometimes battery light stays lit with key out (jiggle key in ignition and it goes out), at random times doors unlock, usually before or after engine cuts out, if running and I turn on cabin fans engine revs up significantly but settled back down (not all the time but random occasions).
electrical harness possibly pinched by either of the not so pro mechanics who butchered the engine or trans install? Possible ECU "dead spot" from years of off-roading? Anyone with idea please advise.
Just as above I'm needing some serious help.
Parts now new and still randomly dies either at speed or at idle.
Alternator, battery, throttle body, fuel pump, fuel pressure regulator (will install in 3 hours delivered yesterday), engine, transmission, all grounds are good I've check this multiple times, transmission neutral safety switch/gear selector, 4x4 actuator/selector (on top of trans), ignition coils, spark plugs, under hood fuse panel and fuses, starter. I've thrown thousands into this thing and nothing has fixed this issue. Dies at random but starts up after a few seconds without any issues.
Other odd things, sometimes dash light on display show odd symbols after key removed, sometimes battery light stays lit with key out (jiggle key in ignition and it goes out), at random times doors unlock, usually before or after engine cuts out, if running and I turn on cabin fans engine revs up significantly but settled back down (not all the time but random occasions).
electrical harness possibly pinched by either of the not so pro mechanics who butchered the engine or trans install? Possible ECU "dead spot" from years of off-roading? Anyone with idea please advise.
06-12-2017, 09:31 AM
#2
TECH Senior Member
One possibility- ignition switch (did not see it mentioned above; sounds like a possibility)
06-12-2017, 02:46 PM
#3
I had changed the key ignition switch about a year ago. I thought about this too. I will add it to the list.
How about crank position sensor??
This morning I swapped in the new fuel pressure regulator, would not start. So I just pulled battery leads taped them together to do the old style Ecu code clear, started it up and it had the crank sendor code "pending" as it was running the code came to be hard coded and through the Engine light on. I changed this too when I did the motor swap (well I paid to have this changed my guess is the part went into someone's tool box with a bunch of other new sensor I provided and paid for on the bill but later found out none were changed).
Now this is strange too, which leads me to a bad wire possibly, alternator is about a month old, very little run time on it. But now battery gauge is showing 15 V. I will check this with my meter though.
How about crank position sensor??
This morning I swapped in the new fuel pressure regulator, would not start. So I just pulled battery leads taped them together to do the old style Ecu code clear, started it up and it had the crank sendor code "pending" as it was running the code came to be hard coded and through the Engine light on. I changed this too when I did the motor swap (well I paid to have this changed my guess is the part went into someone's tool box with a bunch of other new sensor I provided and paid for on the bill but later found out none were changed).
Now this is strange too, which leads me to a bad wire possibly, alternator is about a month old, very little run time on it. But now battery gauge is showing 15 V. I will check this with my meter though.