mxcrazed

hey guys i know you frown on talking about other cars in here but i want to sell my dads old 94 suburban (which is odb 1)because he is out of work right now and it has been sitting for about two years and it ran when he parked it then the problems started and eventually it stopped running it has spark timing air and compression the problem is fuel/electrical the fuel lines are fine and the fuel filter is new and so are the injectors i have it down the the computer as a matter of fact i called the stealership got the correct numbers and retrieved another computer from a salvage yard and it turned over but then it was sputtering and stalling and when i looked at the fuel coming out of the injectors it would flash white ish then choke and eventually it would no longer turn over .

this is why i replaced the computer... i tested the lead from the computer to the fuel pump relay for continuity i tested the fuel pump relay i jumped out the fuel pump and i tested for voltage at the lead to the fuel pump relay and it was dead so i replaced it and got a live feed to the fuel pump relay and it ran please i know nothing about the computer or how to burn a prom if one of you could point me in the right direction as to why the computers failed any ideas are appreciated

Pre-Tuner

iTrader: (2)

I don't think the ECM has anything to do with it's ability to turn over. The starting circuit is pretty simple, so I would check out the battery/cables/etc. Since it would start once, it could be a bad cable or ground.

The PROM is definitely not the problem.

mxcrazed

there is no problem with the starter or the starting circuit for that matter perhaps it went over your head but thank you for your input the vehicle ran after i replaces the computer that was not providing voltage to the fuel pump relay with the one that did although it did not run when i jumped out the fuel pump with a jumper across the switch meaning i removed the relay and then manually switched the fuel pump on my problem is that i had a perfectly good computer in the car and then it stopped working miraculously then i replaces it with another and it ran although poorly then it miraculously stopped running again now i want to know what would cause this to happen the battery has died multiple times and it did sit for about a year before it would no longer run when jumped then i began work on it and talked to a few mechanics who believe that i need to reprogram the ecm for it to run maybe it got flashed accidentally possibly someone shorted something to the engine block (speculation) as i read earlier that the ecm is grounded to the block on the passenger side
i am basically grasping at straws here but i have the brain to deal with any issue regarding the engine or computer although possibly not the means to burn a prom but i will look into that i just need help to diagnose what happened and where to start i am nearly 100% sure it is a computer issue the fuel system is fine and it starts when i introduce fuel into the intake manifold the injectors have voltage (lean rich lean rich pulsations) they are new the fuel filter is new the fuel lines have been replaced due to rot the fuel pump runs when i jump it out but i do not know why there was no signal from the ecm to the fuel pump relay and i do not know why it did not start when i jumped out the fuel pump i will have to go back and see if the replacement computer is doing the same thing the original one did
any hints are appreciated and i am quite confident it is one of these
1.computer
2.fuel pump is operating intermittently don't only point the finger at the obvious here

Sonix

iTrader: (1)

'94 Suburban? fullsizechevy.com has a lot of guys on there that know their stuff, and TBI motors are more common in that application than third gens. Just another option...

galvarado

If it's been sitting for two years I'm sure there's all kinds of crap sitting in the tank. That's what happened to me. When I had the tank cleaned it came out of the dip full of holes so I replaced it and haven't had any problems since. So it's a possibility your tank might need a cleaning and some fresh gas.

mxcrazed

thanks guys ill go to fullsizechevy.com and check out what they have to say as far as the tank goes we filled it and had to empty it because the seal dry rotted from having less than 1/2 tank and we didn't get any gunk out if it but if i have to drop it for the fuel pump i will be sure to clean it