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  #1 (permalink)  
Old 04-27-2006, 07:09 PM
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Default Think I have a fuel problem.

Took the car out for a ride this afternoon and had a bit of a problem. The car ran strong but after a brief blast up to 6000 rpm the car cut out and wouldn't fire until I let it sit for awhile. Got rolling again with no problems but as I passed under the highway overpass near my home I jumped on it again ( lets the wife know I'm almost home) and again as I slowed for a light it cut out and wouldn't fire for quite some time then seemed fine again.

Got the car home and noticed that the fuel pressure is only reading about 3 lbs. now and was set at around 7 last I checked. Every component of the fuel system is new from the tank to the carb and can't believe with under 500 miles that this is happening. This is the first car I've owned with an electric pump (Holley) and I guess my question is could the pump fail so quickly? It doesn't seem to have the same sound as it did so I'm inclined to think this is the problem. Is there anyway to test the pump itself? Can't seem to get in too many "quality" rides in without yet another bug or two creeping up.

Thanks,

Dale
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Old 04-27-2006, 08:06 PM
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I assume you have a regulator? Have you tried to adjust it?
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Old 04-27-2006, 11:32 PM
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Dale,

Typicaly, fuel pumps either work or they don't, unless your losing a ground to the pump. Do you have a fuel cutoff from a low oil pressure switch or from a temp switch?

Chris
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Old 04-27-2006, 11:32 PM
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Test your pump by pulling the fuel line on a cold engine and turning it on and see if it squrits. I've found that when I set my pressure @7lbs when I first start the engine and then lock it down, it will always show something different when I get back from a ride. I've learned not to readjust, like the Ronco guy says, "just set it and forget it".
Tim
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Old 04-28-2006, 06:26 AM
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The next time the engine quits and won't run, turn off the engine, remove the air cleaner, look down the carburetor and move the throttle to full open one time. If there is fuel in your float bowls, you will see fuel being squirted into the engine by the accelerator pump. If there is no fuel, turn on your key and confirm (by sound) that the electric fuel pump is running for at least ten seconds. Turn off the key and repeat the test for fuel in the carburetor.

If you can hear the fuel pump running, but there is no fuel at the carburetor, you may have a clogged fuel filter or you may be experiencing vapor lock. It is also remotely possible that your fuel pickup is at the front of the tank and under low fuel conditions, fuel is sloshing away from the pick up during hard acceleration.
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Old 04-28-2006, 06:55 AM
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You may have an electrical problem, maybe a coil or ingition switch. With an electric fuel pump, they almost always keep the same output and pressure. I would suggest you put a test light on your coil and have it so you can see it while you drive. when it shuts down you can see if the light goes out. it may help you find the problem.
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Old 04-28-2006, 08:45 AM
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Ditto on the fuel filter idea. When running hard the gas is flowing well through the filter and pushes all the junk up against the filter element slowing it down. Letting it sit allows the junk to settle and the fuel to flow again.
I had the same problem last month and when I pulled the fuel line and ran it into a can the fuel flow started out ok and went down to a dribble within a couple of minutes. Cleaned the filter and it flows just fine now. You may have to do this twice to get it all out.
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Old 04-28-2006, 08:52 AM
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Make sure your positive lead to the fuel pump is a heavy gauge wire and not a smaller gauge, like 16+. Use a good heavy gauge like 14 or heavier.
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Old 04-28-2006, 11:45 AM
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Yup, fuel filter is highly suspect!
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Old 04-28-2006, 02:23 PM
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Where is your fuel pump located. I ask this because electric pumps don't pull very well but once they have prime they will push very well. Almost sounds like when you jump on it it looses prime but when it sits the fuel makes it's way back to the pump. I rectified this problem once by placing my pump below the level of the fuel tank & as close to the tank itself as possible.
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Old 04-29-2006, 09:01 PM
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Thanks for all the replies. I've been pulling some doubles at work and the Cobra problem was put aside for awhile. I do have a regulator and reset to seven pounds, installed a new fuel filter and examined the new street avenger which is working fine. I fired her up and let here run for awhile but the sound of the pump has changed. Sounds almost like something rattling around in it and it's not as loud as it used to be. After idling for a bit I took it out and after a few minutes it cut out again and I couldn't here the pump at all when I tried to restart her. It almost seems like the pump is heating up and cutting out and after cooling begins to partially work again. I think I'm going to replace the pump and see what happens at this point. I always thought as someone mentioned that a pump just stops working period but who knows. I'll post the results of the change.

Thanks again for all your thoughts.

Dale
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Old 04-30-2006, 08:57 AM
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Default RTV in the fuel line????

My Cobra did the same thing about two years ago. It was RTV in the fuel tank that worked it's way into the fuel line and plugged up the fuel filter. I have a filter between the tank and fuel pump. Long thin strings of jelly RTV. I guess it came from the RTV that was used to seal the fuel sending unit. It took two years to plug it up and stop the motor. Check all the places ( filters, pumps, etc ) that trash can accumulate. If you can, blow air thru the lines to clean them out. Small problems, easy to fix but hard to find!
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Old 04-30-2006, 10:42 AM
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I lost my fuel pump in London. Did most of what Dwight mentioned above.

Lucky there was a Jegs.

Anyway, I ended up removing any syphon problems from the fuel system.
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