Need help with a truck.. 88 Chevy 1500

Brandon5778

Petty Officer 2nd Class
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Jul 9, 2016
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141
Hi guys. I made an account on a truck forum to ask this but I am not really getting any responses.. So I figured all the boaters here have trucks, and they'd be more than willing to help out.. Anyway my brother and I are working on a truck that hasn't ran in 10 years. It was our Gramp's truck. He's gone now and it's up to us to work on it. 350 TBI. We have spark, but not getting fuel. Ignition is good because we started it once for just a second by spraying starter fluid down the intake. Otherwise just turns over. We have already drained and cleaned fuel tank, and decided to test the fuel pump on a battery. It was bad so we replaced it with a new one. All back together and no fuel pumping.

So, I started checking for power everywhere. No power at the plug that plugs into the pump whatsoever. Under the hood the fuel relay has a hot orange wire and the fuel pump fuse does have power when the key is turned. Looking at a wiring diagram it seems that the fuel pump fuse is the last thing before the wire travels to the fuel pump.. and since we have no power at the pump but do at the fuel pump fuse, it leads me to believe there's a short somewhere in the wire traveling back. The ground on the pump is good, I cleaned it up nice and shiny bare metal. Any input is appreciated, not sure where to go from here.
 
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GA_Boater

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49,038
Get a long hunk of wire, connect one end to the battery + post and tap the other end on the input to the pump plug to make sure the pump runs.

But before that, swap the fuel pump relay with one of the others, usually the same type/rating of relay is used for other circuits.
 

Darrenmb

Petty Officer 3rd Class
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Oct 19, 2016
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There is a way to jump the fuel pump circuit from the obd1 connector, cannot remember which pin it is anymore, im sure a quick google search will tell you, that is of course after you follow above suggestion to ensure wire is good
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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there should be a fuel pump primer lead under the hood near the ECM.

as GA stated, swap the relays.
 

dwco5051

Commander
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Sep 14, 2008
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2,326
Not sure on that model but it might have a fuel pump inertia cut off switch that needs to be reset. I forget which truck I had many years ago and if you were plowing snow and hit the snow really hard trying to buck it up into a pile the truck would quit and and I had to reach under by the glove box and reset it. They are installed to prevent an electric pump from keeping on pumping in case of an accident. If you towed the truck and were rough with it it may just need reset.
 
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Brandon5778

Petty Officer 2nd Class
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Jul 9, 2016
Messages
141
Ok, did just a few things today but it started raining and interrupted and never got a chance to try to start it. Got a new relay, haven't put it on yet though. The pump does turn on if we jump it directly to the battery. One quick question, in the pic attatched below is the wire that I think is the lead to jump the fuel pump that was mentioned. Just want to confirm this is the correct wire before giving it +12V. The one that is just hanging on the end is what I think is the right one.

Dwco, from everything I've read I don't think this truck has the inertia cut off. Thanks everyone for the fast replies, I'm hoping to get back on it tomorrow evening.

2e3v28l.jpg
 

Brandon5778

Petty Officer 2nd Class
Joined
Jul 9, 2016
Messages
141
Got the truck running! I think it was corroded wires inside the fuel tank. We replaced all the wires inside it and cleaned up the grounds, hooked it up outside of the tank and turned the key and it turned on. So we put it all back together and she fired up and is running. Now we have to go through the brake system, left rear brakes are locked up and for some odd reason there's a snapped brake line right by the resovior.
 

WIMUSKY

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Sep 26, 2009
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Congrats! Electrical problems can be a pain in the rectum......
 
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