88 K5 not running - help!!

[SoonerBob]

Ok, I have a 1988 GMC K5 Jimmy 4x4. Lately it hasn't been running very well and has gotten progressively worse until today it wouldn't even idle without dying. It's also doing something really weird - none of the electronics (map lights, radio, headlights, anything, etc...) will work unless the truck is running. I checked all the fuses and they're OK so I'm stumped there. Next is the truck not running. I know it is starving for fuel since it will run on starting fluid but it wont run without it. I would think it would be the fuel pump that is the problem. Now the fun part - I don't know where the fuel pump is It has an aftermarket electric pump, not a mechanical one but I'm not sure as to where one would mount it but I'm hoping it's not on top of the gas tank. Anyone know what I need to do before I go find the fuel pump and replace it?

 

[spydermonkey454]

the fuel pump is in the tank

sounds like you are not getting battery power to the vehicle
but you are getting alternator power??????

better check for voltage at fuse block

 

[big dan]

might try a new fuel filter

 

[absolute]

Check your terminals and ground points from your battery.. Just a thought, my neighbor had a very similar problem the other day on his 86 K10... rang my doorbell and asked if I could help out... and thats what it was!

 

[SoonerBob]

put in a new fuel filter, still didn't work. I'll check all the terminals and ground points tomorrow sometime when I have more light/time. Thanks guys.

 

[dyeager535]

On a TBI truck, even if the fuel pump is good, the ECM has to tell the injectors that the engine is cranking before they will fire. In other words, all ether does is provide fuel, spark is always present given everything there is working right.

You can check for an injector pulse with a "noid" light, I'm going to guess you don't have an injector pulse.

"crank no run" links here http://coloradok5.com/forums/showthread.php?t=141717&highlight=troubleshooting are what you can follow to troubleshoot.