Hookedontims

Hey all i have just picked up an old 88 Chev 1/2 ton with a 305 EFI engine in it.First the thing was stored inside for the last 14 yrs. I can get it to start every time i try it but, it will only stay running for a few seconds 5-10 .it sounds great for the few seconds it is running..no smoke or nothing ..it has 150 thousand kms.on it.
When i do get it running ,if i pump the heck out of it it will stay running roughly. I have changed the injectors with working ones out of my other truck which is the same model and year. Swapping them did nothing. I have all the sensors and everything to try off of the working truck.
Any Advice would be greatly appreciated..thanks in advance.

manic

Fuel pump, fuel filter, the tank may have a bunch of gunk in it. Was
this thing stored all this time, was it ever ran? Gas contamination would
be my first concern, varnish, and gunk.

Hookedontims

I forgot to mention ..sorry.. the fuel filter has been changed. It has been started perhaps once in the last 3 yrs i'm told. I have been told that a fuel pump would just die and be done and the thing would not even start if it was gone is that not true or do they work a bit before they go? The gas seems to smell ok and looks decent but as you said it could be the prob.

Since my first post i have swapped from my good running truck every part on and around the throttle body except for the EGR valve.
Any more advice would be great.

Thanks for your fast response.

manic

A fuel pump, can just go kaput, and thats it. But not always. I had
a chevy van once, if you kept pumping the gas pedal it would stay
running, but as soon as you stop it would die, replaced fuel pump,
problem solved. The same thing sorta with a ford taurus. Would work
sometimes, be ok, then die. Let it cool off it would be good for about
a day or 2, then finally died. So the answer is yes and no on just
dying. Theres a voltage test you can try, I forget the procedure,may
be someone else will chime in with the answer. If you do end up changing
it, dont take the whole bed off, you just have to loosen the bolts up
on the bed and jack up one side, its tight but alot easier then taking
the whole bed off.

wrench97

Check the fuel pump relay and the wiring on the oil sending unit the ecm will turn the pump on while cranking but then it needs a signal from the oil sender to stay engaged some are run through the ecm some just ground the relay through the oil switch and some others receive the relay power through the oil switch. for a test you can jump the fuel pump + wire to + battery at the relay socket and see if it stays running.

Hookedontims

Tried everything you said except for testing the fuel pump , i did syphon out the gas that was in it and put in fresh gas ,still no luck acting the very same ..thanks for now will go at it again tomorrow..feel free to add things i might try

BUDFAN8

there should be a single wire coming out of the harness on the driver side of the fire wall probley has a spade end, if you can find it its hooked to nothing. that is too your fuel pump if you run a hot to it your fuel pump should stay on all the time. run the hot see if it will start if it stays running your fuewl pump should be ok. make sure to use this only as a test dont try to leave it that way or it will eventually burn the fuel pump up.


Bud.

Hookedontims

Thanks for all the advice guys ..i decided today to take the box off and checked the fuel pump. It was gone..i put in a new one and all is a go. Thanks Again
Gerald