Have a 95 Topkick with the 6.0 litre (366) TBI engine. Put a new distributor in last year and truck ran great. Went to start it on Saturday and now isn't getting fuel. The fuel pump used to cycle for a few seconds when you turn the key but now nothing. Starts if you put fuel in the throttle body but doesn't stay running. Fuses appear to be good but apparently there may be a rest button on the fuel pump relay? Not sure where that is or if the fuel pump is in the tank(s) or maybe the inner frame rail. Where's the best place to start to try and locate the problem.
dave --- I believe the pump is in the tank on a topkick
If you have a helper, I'd start by turning the key repeatedly while stomping the floor, and having the helper tap the fuel tank every which way. then bust out the multimeter if that fails to get the fuel pump running.
Had power at both connectors on top of the fuel tanks but wasn't sure if they are for the fuel gauge or fuel pump or both. The fuel gauge isn't accurate but have read that's a common problem.
Wonder where the ground is? whether the wires are for the gauge or pump. I wouldn't think the tank would be the ground. wiring diagram or tracing time.
I can't find a large enough diagram of the fuel/electrical system to see where everything is located. I had another guy looking too and we couldn't locate the fuel pump relay. Usually it's not hard to find info on the internet but not for this. Might have to see if a dealer could print something for me.
Fuel pump relay is on firewall, above distributor, next to electrical panel. Not near my 366 C6500 this week for pics of parts. No reset on it.
Did you also check to see if it was fireing the sparkplugs ? From what i have saw and been told its a must to carry a spare dist with you the fuel pump will not work and it will not fire. I have replace several dist on the TBI 366 were the pump wount run and it had no spark.
Did you read my original post? I put a new distributor in last year and the engine runs if you pour fuel in the throttle body. The fuel pump isn't coming on when you turn the key.
Sorry i did read every thing but the first sentence. I still wouidnt rule out the dist. One of the dump trucks at work i replaced the dist and it lasted less than a year. I also had one that wouldnt start off the key it would turn over good but if you crossed the starter it would.
I had it running for about 15 minutes last year when a friend put the new distributor in. It ran great but unfortunately that was the only time it was started since I tried on Saturday. I took the VIN to a dealer and discovered why we couldn't find the fuel pump relay. It's not on the firewall but on a cross member on the frame in front of the left side fuel tank. I don't think it's the problem though. I didn't have any help but I put a volt meter on the wires going to the fuel tank. There are 3 connections. I think the far right is ground and the other 2 are for fuel gauge and fuel pump. Key on, the 2 outside wires have 12.6 volts. 2nd wire in has 13.26 volts for a couple seconds when you turn the key on and then goes down to .4 volts. I think indicates there is the power for the fuel pump. The gas is a little stale and I think could have gummed up the fuel pump. There is a bung on the bottom of the tank but I think it could be a nightmare trying to get it out so am going to make a siphon hose to use with an air compressor to get the old fuel out. There are 2 different pumps for the left and right fuel tanks. I think I'm going to have to move the tank out to remove the fuel pump and sending unit. Looks like you need a special tool to remove all the fuel lines and vents?