Fuel Issues

[Hockey369]

Hi all, I've been researching on here trying to find the source of my problem. I have been chasing fuel issues for about 2 weeks now. I have a 1987 V30, 454 TBI, SM465.

I was drive around all fine, started and stopped at different places multiple times during the day. At night i went to start my truck to go home and it started and then died 3 seconds later. It would not restart at all. It was late so I left it til the morning. I noticed my fuel slector switch must of got knocked and it was in the middle, so i moved it back to the right side tank (no left tank installed) and still wouldnt fire. It would run on starting fluid though so i know its fuel related. Started checking things, tracing them down, changed the fuel relay, getting power through that now. Thought it was the fuel pump since i couldnt hear it running, changed that and then i started getting 0 volts on the wire to the pump (i had power before i decided to replace the pump). Went back and tested my old pump and it worked so now I know there is some other issue. Well I jumpered out the switch and connected the Tan/white wire to the gray wire and now my fuel pump will run and pump fuel. I thought, great, now it will start. No dice! Still is not getting any fuel through the TBI. I checked and tested all the fuses under the dash and they are all good. I cant seem to figure out why my injectors will not fire. I cannot smell any fuel when the pump primes or the engine is turning over. The fuel pump is definately running though during those operations.

I have been trying to trace down what it can be and cannot figure out why my injectors will not fire!?! Anyone have any clue? This is my first square body and i am reading and learning but I am stumped right now. Also after replacing the fuel pump, my fuel gauge is now max way passed full. I assume this is a ground issue somewhere and not sure if that would effect my truck not starting?

Sorry for the long post, and thanks in advance for your help!

[mrolds88]

The injectors need a certain amount of pressure before they will fire. Did you loosen the lines on the back of the throttle body? See if you are getting fuel there. They do make a fitting to mount a fuel pressure gauge on it. Also could your fuel filter be plugged?? Or your regulator be bad??

[Hockey369]

I have not loosened the lines on the back of the throttle body yet. I was figuring the issue was electrical since everything was all gravy until the switch was hit. Now with the switch jumpered out and set on the right tank, I am not sure what the issue is. I will check the lines at the throttle body and rent a gauge from autozone to see what the pressure is there.

Where is the fuel regulator located? I have not checked that. Would that be what is listed in the wiring diagram as the fuel module? That was going to be my next step but I have no clue where its located.

Do you know where the fuel tank selector valve & meter switch is located? I want to test that as well.

I am hoping its not a bad fuel filter since it was running fine for the 2-3 weeks i've owned it and then just stopped working completely. Plus the fuel filter is rusted to the lines so i will have to replace all the fuel lines if i want to replace the filter. I cannot find the lines for my truck at LMC or online.

[mrolds88]

Regulator is on the throttle body. Its the piece that the fuel lines thread into. The selector valve should be on the inside of the passenger frame rail beside where the passenger tank is. Since your fuel lines are in that bad of shape, it might be wise to look into rebuilding them. I know NAPA sells "repair ends", and all you would need would be some 3/8" fuel rated steel line, some unions and a flare tool. I think that would be the safe thing.

[83GMCK2500]

Originally Posted by Hockey369

Plus the fuel filter is rusted to the lines so i will have to replace all the fuel lines if i want to replace the filter. I cannot find the lines for my truck at LMC or online.

Really? LMGTFY I opened the first two, inline tube & classic tube. One for sure has them listed and the other sounds very promising as well.

[83GMCK2500]

Ok. You mentioned you do not have a left tank? Are the lines capped? Do you still have the selector valve? I wonder if when the switch was bumped the valve sucked something into it and has blocked fuel.

[Hockey369]

Ok, over the holiday I didnt have much of a chance to look at it, but since the fuel filter is rusted on and I have no clue how old it is, I am going to replace the fuel lines and filter. 83GMC thanks for the links, I wasnt sure on those since it didn't list the 1 ton variety on them when I first looked.

My question is, would there be any issue with just running a line from the tank to the fuel filter by passing the valve? Since I only have one tank and have no plans to ever put a second one in (only using as a driveway plow and dump runs truck), I would never use enough gas to even warrent filling up two tanks without one tank getting old. It takes me now over a month to empty one tank 3/4 of the way. I was planning on just running a new fuel line to right after the fuel filter. Would there be any issues with the return line? Should I skip the valve on that one too just to make sure?

Thanks for all your help! I will eventually get the truck running again!

[mrolds88]

No. Shouldn't be an issue. Only thing I would do is to remove the switching valve out and wire the sender and pump direct. Meaning hooking up the wiring coming from the tank to the wiring coming from up front. Also bypassing the dash switch.

[Hockey369]

Thanks. That's a good idea as well. I was going back and forth on whether to do that or not. I have a new switch I was going to install but i think having it directly wired would end up causing less issues in the long run.

At the switch, basically the switch makes the tan/white wire connect to the gray wire for the pump, so I will just solder those together and put some heat shrink on the connection. For the sender, which wire would would be direct? Right now the pink/black coming out of it goes to the meter switch, would I wire this directly to the gauge??

[Hockey369]

Well, I replaced the fuel line from the right side tank up to the braided stainless line that is going to the TBI. Put a new fuel filter in (bunch of dirt came out) and it fire right up!!!!! So it looks like the valve was the problem, it was either filled with crap or stuck in one position but now that its outta the way, the truck runs great! Now I gotta fix the fuel gauge and get that working again as it was fine before i dropped the tank. The ground from the sending unit to the frame broke off so I am betting that is the issue with the gauge. Thanks for everyones help!