Ok, in my bro's 84 gsl we have now gone through 4 fuel pumps. First we burnt up a stock pump out of a parts car, then 3 napa pumps. This is really starting to annoy me. They work for awhile, all four of them have worked at some point, but after taking them out and putting 12 volts to em, they do nothing. Completely dead.

Im really confused here, we tested out the alternator, it seems to be good, i say this because the only conclusion i have come to is voltage spikes or something. I don't understand why the fuses aren't popping instead of burning up my pumps...

Anyone? any ideas...im lost here

 

If voltage is not a issue, then I would start looking for a bad ground(s).

John

 

did you change the fuel filter?
the pump is cooled by the fuel passing through it....if the filter is dirty, it can cause the pump to burn up....

the 84/85 cars have a fuel pump relay so i doubt voltage is the problem

 

yeah change the filter

 

if the filter doesnt help, get a pump from someplace other than napa

 

Do the pick-up tubes ever get plugged up with gas sludge in these cars? I've had some experiences that've made me wonder about that.

 

well im getting another pump, this time not from napa...

and yes, ive replaced the filter, a new one came with every pump i got so i just replaced it everytime...

bad ground could be a possibility but would that cause the pump to fail everytime??? im thinking maybe the could have some sludge built up in them, but when i unplug the fuel hose to the carb and crank the engine it seems to flow really well....

this problem sucks because we are trying to troubleshoot carb problems, but its hard to do without fuel! Another thought, if we are having carb problems, like say the needle valves are sticking or for some reason the floats are all the way up....thats going to stop the flow of fuel and put lots of pressure on a pump...that can cause a pump to burn up right????

 

The '84 has a drain plug in the bottom of the tank, have you tried draining it? See if you have so much sledge, you may have to drop the tank to get to the pick up tube/screen.

 

we've dropped it twice now, and originally there was really bad sludge, it plugged the line coming out of the tank, but i thought we got most of it the second time...hmmm maybe 3rd times a charm???

 

wow sludge huh? i guess i got lucky, when i dropped my tank to install bigger pickup/return line it was brand new inside, i even had some fuel tank repair kit i was going to use predicting the worse,

go get one of those walboro 255lph (or a holley blue) pumps off ebay for 100 bucks (why replace a stock pump that sux with a new stock pump thats gonna suck too?), and a bypass pressure regulator, to knock it down to 3psi, you may have a cloged return line (or the check valve in the return line/near the carb is clogged itself) burning up your pump,, blow it out with some compressed air when you drop the tank next.

i would not worry about the needle and seat thing, if it goes bad your car wont run (stuck closed) or it will flood it out (stuck open).

Carl.

p.s. make sure your getting a correct fuel filter that wont cause a restriction. also check all the fuel lines, (p.s. REPLACE THEM ALL!!

 

Got my Walbro, (carter,federal mogal, all the same pump), from NAPA for $69. It isn't NAPA'a fault your tank has sludge in it.

 

^ correction, my tank had sludge in it...i now think its something with the return line...i can't blow air through it, but thats back from the carb...will the check valve not allow air to go through that way???

 

That is what a check valve does, allows the extra fuel to return to the tank, but will not allow the fuel to be drawn from the tank on the return line.

J.

 

What does the fuel pump relay have to do with the voltage??

 

You should be able to blow into the tank through the return line.

Well, I don't want to insult your intelligence by asking real basic Qs, but four pumps says you guys are missing something!

Did you prime the pumps each time?
Have you checked the pump cut relay? You can bypass this so that the pump runs continuously when the key is in. (Or just disconnect the pump and hook wires up to a battery.)
Try keeping the gas cap off to allow the tank to breathe (you may have a clogged tank vent - It's pretty common).

The stock pumps are piston type pumps, and have little draw for self priming. You're relying on gravity to get the fuel down to the pump.
Are you trying to do this with one inch of fuel in the tank?

 

He didnt get enough fuel that the pump wants to move, so that wore it out. I worked at NAPA and have one of these pumps he's talking about. I also finally fixed my rusty *** gas tank that just stoped and clogged for good on me, when I had to change the filter every 200 miles. You need to get that tank fixed or new one or fuel cell. Take it from me, dont mess with it until its fixed, you'll end up with dents in your hood (punched it).