1991 Chevy S-10 Short in the fuel pump circuit

JWILL226

MEMBER
1991 CHEVROLET S-10
6 CYL
2WD
AUTOMATIC
240,000 MILES

I did a fluid and filter change in my S10. I changed the fuel filter as well. For a short time the engine would go threw periods where it seemed starved for fuel. Mainly but not limited to when cold or hauling weight in the bed.

Three miles after changing the filter my truck died on the side of the road with out warning. Here is what I have found:

--10A ECM1 fuse blown
--When replaced the pump will come on with key on 'RUN'
--The fuse blows when turned to 'START'
Volt meter shows 12+v at 'RUN' slight normal voltage drop at 'START'. The truck started with voltmeter in place but ran rough (possible air in the line from filter change?). I shut it off right away so not to hurt any thing else.

How do I trace out this short. Or is it even a short. Could a component be bad?

1 Reply

MMPRINCE4000

MECHANIC
8,549 POSTS

First make sure you have the correct fuel filter and it is not on wrong, the arrow should point towards engine.

It is also possible that the pump is bad.

The pump should run for a few seconds when ign. Is on, then shut off. If it runs all the time with ign. On you have a bad relay.