1989 GMC V3500 won't start need help

[1989CCD]

My 1989 GMC V3500 crew cab dually 7.4 TBI won't start it's been sitting for awhile cause batt was dead finally got around to getting a new batt and now it won't start. It turns over but it's not getting any gas my gas gauge is pegged to past full and when I switch from tank to tank it doesn't move I can hear drivers side fuel pump running when on LH side switch but when I switch to RH side I can't hear pump running on passenger side. It has gas in both tanks and fuel filter is newer and I took it off and checked it and it's good. Any ideas of what I should try next. Thanks.

[68c10airstream]

Any no start you end up dealing with a check for spark first, then go to fuel related items. With a tbi if you have spark then take some carb cleaner and spray a little down the tbi throat and if it fires up, then dies you will end up checking to see if the injectors are working. An easy way is to take a broom handle and touch the tip to the injector body and stick an ear to the side of the handle, plug the other ear and have somebody crank it over and listen for the injectors to be ticking away. No ticking, check for a blown fuse.

Tbi's have more trouble with fuel pump, pump wiring issues, fuel pump relay issues as a general rule. This will be a good starting point.

I'm in the midst of my daughter's subaru valve job, etc, but pm me as i know the no start specs and procedures off the top of my head, or look at my post responses as i went through the distributor checking steps responding on a different thread a while back. Good luck.

[1989CCD]

Ya it has spark and I sprayed cleaner in it and it started for a few seconds then died i replaced the dash tank switch because it happened once before and that fixed it but not this time. I'll have to try the broom trick tomorrow. Thanks.

[1989CCD]

So I think may be the fuel pump I can hear the driver side run but what i hear is the pump run and sounds like someone pouring gas in the tank I dont think that is the normal sound should just hear the pump running correct ? not gas moving around? Im pretty sure passenger side pump is toast i cant get it to turn on with the test wire.

[Greenlee]

Originally Posted by 1989CCD

So I think may be the fuel pump I can hear the driver side run but what i hear is the pump run and sounds like someone pouring gas in the tank I dont think that is the normal sound should just hear the pump running correct ? not gas moving around? Im pretty sure passenger side pump is toast i cant get it to turn on with the test wire.

There is a short piece of hose attached to the pump inside the tank. I think it's pretty common for that piece of hose to rot away and fail. Since you can hear what sounds like fuel pouring, that would be my guess.

[1989CCD]

Ya thats what I was thinking also not what I wanted to hear lol not looking fw to pulling the tanks. Guess i'll give that a shot and see if that works i've tried everything else I can think of and it doesn't throw any bad codes so it's got to be the fuel pumps. Thanks for your input

[68c10airstream]

Both tanks to deal with?? Pull the box off of the frame is easy and then you can stand over them and diagnose electrical issues and easily pull the sender out the top and not fight with those awkward long narrow tanks, especially if the tanks have a lot of fuel in them.

[Desert1957]

Originally Posted by 68c10airstream

Both tanks to deal with?? Pull the box off of the frame is easy and then you can stand over them and diagnose electrical issues and easily pull the sender out the top and not fight with those awkward long narrow tanks, especially if the tanks have a lot of fuel in them.

FYI, I own a 1991 Crew Cab Dually with 7.4 and TBI , You CANNOT get the senders out with the bed removed. Been there doesn't work, Sorry....

[1989CCD]

Ya I noticed that so I just dropped the tank was a pain. Haven't got around to putting it back in yet seems like it's going to be tuff getting it back in.