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Fuel pump issues


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I keep burning up fuel pumps on my 79 GL wagon and I don't know why. This is number 3 in 6 months. The only thing I can think of is when she sits for a while ( a day or 2) I have to crank her for 10 to 20 seconds to get fuel to the carb. Would this kind of cranking burn up the pump until I get fuel there? The pump would be dry until it gets fuel.

 

It's always been a challenge to get her running when she has day in the past but I haven't been burning up fuel pumps. O'Reilly has the for $70. I am taking this one back for warranty.

 

Any help/advice is appreciated.

Edited by Dan-AZ
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This is on your 79 right? If so because of the placement of the pumps on these older rigs you might have a cracked rubber fuel hose somewhere before your pump, making the pump suck air and work harder. Another thing is your pump shouldn't have to run at all to start the car, there should already be enogh fuel in the carb to start it.

Things to check, see if the fuel level is right through your sight glass, check the rubber parts of your fuel systems for cracks (if in doubt replace), maybe try a differant brand fuel pump.

Have you been noticing any other problems? Lack of performance or bad Mpgs

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Brand new fuel filter, I put that on 3 or 4 months ago. The fuel line looks good from the carb to the firewall on the right side. I've never had trouble with a bad line like that without smelling gas. I don't smell gas any more since I did a float adjustment on the carb.The sight glass looks good when the fuel pump runs.

 

Still getting 28 to 30 mpg here. That's what I have been getting for so many years. I need to do a tune up here and put new plugs, points, condensor, cap and rotor on her. She runs like a top when she has fuel in the carb.

 

Here is the kicker. Once the pump starts doing this, it heats up and quits. Once it cools, it runs for a little while and will run for 5 minutes and then quits. It then repeats the process.

 

I did have a bad ground. A mechanic friend stated that a bad ground might cause the pump to heat up and eventually fail. I will check the lines from the firewall back. I am hoping they are metal lines and not rubber. I will let you know when I see tomorrow. I have never checked. Shame on me.

 

The new fuel pump is in and operation and I have run new electrical wires for a good ground and positive lead. I will dig thru and check my fuel lines tomorrow.

 

Thanks for the reply.

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Yep, I live about 80 miles from sandpoint, I go there every once in a while. You should see what they replaced Dover bridge with, instead of that p.o.s rusted out two lane bridge they built a four lane bridge that bypasses Dover completely and put in an over pass going into ponderay. It sure makes going into sandpoint easier now.

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Lines look weathered, but they are intact and solid. The only place I could not check were where the metal lines run under the floor boards on the right side. I put new clamps on all of the joints to reduce the possibility of air leaks.If I keep losing fuel pumps, this will completely baffle me.

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The fuel pump on my first gen Brat went out.  I took it apart just to see what was inside and it's really a very simple pump.  An electric magnet moves a metal piston back and forth.  The piston has two one way check balls on it.  There is very little to fail.  I cleaned the junk out of it and it works great.  I also put back the prefilter that some previous owner thought wasn't needed.  I think that is what allowed the junk to get in it and stop it from working.

 

As far as air leaks on the tank side of the pump, I think I have one but haven't found it yet.  The lines all look good as far as I can see them.  I suspect it may be inside the tank.

 

I know this doesn't answer specific questions, but it's related and may be a little helpful?

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Yes and no. If the leak is inside the tank, it will a week of labor to take care of that. I found while doing a float adjustment on the carb today that fuel is disappearing from the bowl. There is a pin inside the carb and on the bottom of the bowl where a rod and spring push on. This rod is part of the upper carb assembly. This rod and spring push on that knob.  When it comes to carbs, I am a novice at best. I believe the fuel is going out there when it sits for a while. I cleaned the carb and it seems to start better now. I think that's why it's hard to start after a few days. I readjusted the gasket and tightened her up good. She runs a bit better. I am hoping I don't loose yet another fuel pump.

 

This pump was covered under warranty so I didn't rip it apart. I had a bad ground which can inflict damage to the pump. I reinstalled a better ground this time and things are working OK.

 

Thanks.

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that would explain the hard starting and might have been the cause of the fuel pump failures but i'm thinking this must have only been happening while it sits or i would think you would have noticed mpg's going down.

another possibilty is what vwbrat mentioned the fuel pick up in the tank might have a crack in it, unfortunately the only way i know to diagnose that is to pull the tank and inspect. hopefully your issue is found and you don't loose anymore pumps, but if you loose another pump i would pull the tank and check out the pickup inside the tank. if that checks out i would start suspecting either 1. a bad brand of fuel pumps or 2. carb problems, the draining of the bowl and unchanged mileage would suggest to me a bad brand of fuel pump.

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Checked the bowl level this morning before heading to work. Steady at half way up the sight glass. One weird thing when adjusting the float level yesterday. The car won't run unless the gas is at least half way up the sight window so I have to run the bowl level a little higher at 3/4ths the sight glass. I will check again Saturday since I am taking the motorcycle to work now.

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