1990 Suburban 1500 w 350 tbi. ABout 70,000 on it. Last month it shut off going dwon freeway. Towed it home. It started, ran again about 5 miles then shut off again. Waited about 1/2 hour and it started then ran about 2 miles. Towed it again. Garage told me it sounded like the ignition module under the distrib cap so I replaced it. It started, ran about three mile and shut off again! I got under hood and shook almost all the wiring on top the engine and what was on the firewall and it started. I shut it off. Came out yeaterday and it started, ran about 30 seconds and shut off. Clean shutoff just like turning off key. Now it wont start at all. We noticed that just before shutting off, it makes a low, almost groaning sound that seems to come from under the drivers left area on the firewall, maybe up where the master cyl is. You can just barely hear it. ALmost like if you pretnded to be a hoot owl but the first whoooo was really low and just about 1.5 seconds.

Can this be a fuel pump problem? Maybe the relay on the firewall? If I turn on the key, I dont hear the pump start humming, a relay click or anything cuz the DARNED BUZZER wont stop even with the doors shut. At my wits end. Sound like a loose wire somewhere on top? Id think that except for that strange little noise before shutting down. HELP!

 

What kind of condition is the battery in? How does the charge look?
Have you checked the fuel pressure?
Check the battery ground cable and engine to body / frame strap....

 

[QUOTE=in2pro;286798]What kind of condition is the battery in? How does the charge look?
Have you checked the fuel pressure?
Check the battery ground cable and engine to body / frame strap....[/QUOTE

Battery spins it like a top. As it shuts off, the starter will spin it but no fire. Its like its totally out of gas or there is no spark at all to the plugs. I replaced the ignition module and the cap, rotor, etc all looked good. When I do get it started, it purrs.

 

Can a coil have intermittent problems? I thought it either works or it doesnt. Is the fuel pump relay needed to start it up and then not while running? If so, that couldnt be the cause of it dying while running. Lots of small wires all over the top going from the injection etc to looms on top of a valve cover then to firewal, etc. Which wire in that mess would kill the engine if it had a broken spot?