fuel pump issuses (a new one)

[Turbo 6 Justin]

okay getting closer and closer to doing startup on buddys car and ran into one final snag tonight, when trying to prime the fuel system to check for any leaks the pump did not prime. It has a hot wire kit, and the fender relay is clicking, the rear relay is clicking, there is 12.5V on the hot in lead there is a good ground on the relay, the signal from the key is making it to the back relay, and it even shows 12V out, but the pump will not flip on. It has a few times with the use of the jumper connector behind the alternator. it is so intermittent it kills. we have taken everything apart and cleaned out all the connections and like I said sometimes (like 5% of the time it will work) the pump is a fairly new 340 and when it does work it sounds strong. WE also checked the stock wiring and it did not work either. I am completely stumped, I can't figure out why the relays are working but the pump will not pump. only thing I can think of is that somewhere between the last connector and the hanger assembly in the tank that there is a problem but by my rational it should wither work or if it is working then not work if you jiggle it around and this is not the case. I guess we'll pull the tank in the morning but I was wondering if anyone has had a problem like this?

thanks

 

[Tow Man]

Does the pump kick on when you first turn the key and shuts off after a few seconds? If this is what your experiencing, it's normal!

I just installed my Walbro last week and had that happen. I had to cycle the ignition switch a few times for the pump to build and show pressure on the guage.

It seems the pump only runs continuously when the engine is running. I've read about this somewhere so I wasn't concerned when it happened.

 

[John Larkin]

Try this. Under the alternator should be a white wire with a black male plug end on it (looks like the underhood light plug end). Stick a jumper wire in it and then hook the other end to the hot connection on the back of the alternator. You are now supplying direct power to the pump. It should run continuously, key off or on. If it doesn't run, chances are you have a bad ground. If you're dropping the tank, check that soldered connection on the top of the hanger by the hard lines; it has a tendency to rust, break, etc. Then move forward, looking for continuity in the ground circuit. Electrical problems are grounds 99% of the time.

 

[Turbo 6 Justin]

I know it is not the key on 3 sec prime the pump things since it does not come on at all.

John, we have tried that connector actually it was the first thig we did and I always do to try t figure out fuel problems. I am pretty sure however that jumping that wire to hot still goes through the relay system. either way it does not work. I agreee with ou this this is probably oing to come down to a ground problem and that was the frst place I was going to start looking this morning.

keep the ideas coming