Fuel Pump Intermittent Issue?

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Old 12-02-2010, 04:37 PM
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Fuel Pump Intermittent Issue?

Hoping you guys can help with this one, as it has been going on for quite a while now.

I have a 99 4.6 F-150. SYMPTOM: You get in to start it, turn the key and no fuel pressure....sometimes.

So I have not only switched the fuel pump relay, with the other one in the box, but have also bought and installed a new one with no change to the problem. When you turn the key, you can hear the relay click on, then off in about two seconds. Seems to be working correctly.

Next I lay under the truck, with my ear up against the lowest point in the tank. I have a freind turn the key on, wait a few seconds then off. This is repeated....I can hear the fuel pump make a click both on and off just like the relay. FP never runs, just clicks. We do this, say about 5-10 times, when one of these times the fuel pump comes to life and charges the line with 35 psi of fuel....yes I have a gauge on it. The pump does shut off in direct relation to the relay, since the engine is not running yet. Now, with pressure on the rail, we start the truck and the fuel pump fires back up and runs continuously. You could drive the truck for a few hundred miles and the fuel pump runs perfectly. In fact, if you never shut it off, I am sure you could drive it across the country!

I went out there just now, it hasn't been started in a few days, and the fuel pump charged the line on the first turn.

So the question is...have any of you heard of a fuel pump acting this way? Say it is hard to get started, but once it is going, it is just fine? The big issue is the intermittentancy of it. The damn thing will work just fine in the driveway, but get over to Home Depot with your crap in the back, and it takes you 10-20 turns on the key to get any fuel pressure.

I appreciate the input guys...thanks!
 
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Old 12-02-2010, 05:10 PM
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It's the fuel pump or the wiring going to it. Possibly a corroded connector or bad ground.
 
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Old 12-02-2010, 05:39 PM
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Your symptoms sound very much like what I experienced on my '99. I was having a hard time believing a fuel pump would fail intermittently, but I finally replaced the pump and haven't had a problem since (approx 2 yrs).
 
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Old 12-02-2010, 06:46 PM
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Originally Posted by glc
....Possibly a corroded connector or bad ground.
I kinda thought that too, but why does it run perfectly once the fuel pump finally starts and charges the line?

I am saying that it NEVER comes close to stalling once it is running. You can stand on it, and it runs perfectly! It idles perfectly, not a single hiccup or miss.
 
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Old 12-02-2010, 06:50 PM
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Originally Posted by fairlaner
.....I was having a hard time believing a fuel pump would fail intermittently, but I finally replaced the pump and haven't had a problem since (approx 2 yrs).
See that is where my mind is at. I am used to the old mechanicals, like in my GTO, they either work or they don't!
 
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Old 12-03-2010, 04:09 PM
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Originally Posted by smamas
I kinda thought that too, but why does it run perfectly once the fuel pump finally starts and charges the line?

I am saying that it NEVER comes close to stalling once it is running. You can stand on it, and it runs perfectly! It idles perfectly, not a single hiccup or miss.
It finally arcs through the corrosion and stays continuous till you shut it down and cools off - and it recorrodes.
 
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Old 12-09-2010, 06:40 PM
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Just to close out this fuel pump thread. I replaced the fuel pump and strainer. Starts right up every time. So fuel pumps can work intermittently.
 
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Old 12-09-2010, 06:48 PM
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defiantly electrical happen more often than you know. good luck
 
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Old 12-10-2010, 09:28 AM
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It took me being stranded in town during a rain storm (where I grovelled in the gutter replacing my fuel filter, knowing it wouldn't make a difference) before I decided to throw a new pump at it and hope for the best ...
 
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Old 12-10-2010, 12:32 PM
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I did the fuel pump replacement yesterday. It was a much easier job than I expected. I dropped the tank with about 7-8 gallons in it. Once the tank was out, and the fuel pump replaced, I tilted the tank and drained the fuel back through the vent hose for the filler, right into my gas can. Now the tank was light enough that I could easily put it in by myself.
 
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Old 12-11-2010, 07:10 PM
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I'm having this problem right now. I have a 2003 supercrew that is sitting in the garage and won't run. It wouldn't start awhile ago, so I squirted starter fluid into the intake, and that was enough to get it going. It ran ok for awhile, but now nothing. I don't hear the fuel pump at all when I turn on the key. My problem is the tank is FULL! I guess I'm going to tow it to the dealer and just let them look at it.
 
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Old 12-12-2010, 03:40 PM
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You can get at the fuel pump without dropping the tank if you lift the bed. It's not all that hard.

Check the easier stuff first, like the inertia switch and the fuel pump relay.
 
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Old 12-14-2010, 02:59 PM
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Originally Posted by pitpop
I'm having this problem right now. I have a 2003 supercrew that is sitting in the garage and won't run. It wouldn't start awhile ago, so I squirted starter fluid into the intake, and that was enough to get it going. It ran ok for awhile, but now nothing. I don't hear the fuel pump at all when I turn on the key. My problem is the tank is FULL! I guess I'm going to tow it to the dealer and just let them look at it.
Get underneath the truck and put your ear to the lowest part of the gas tank. Have someone turn the key into the on position, not start. Listen for the fuel pump to charge the line, about 1-2 seconds, it is easy to hear. interesting about the starter fluid. Are you saying that it continued to run after you used starter fluid? Have you also switched out the fuel pump relay?
 
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Old 12-14-2010, 03:07 PM
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Originally Posted by glc
You can get at the fuel pump without dropping the tank if you lift the bed. It's not all that hard.
It was only two bolts on the straps to drop the tank. (Air impact had these off in seconds!) 2 electrical connections, two fuel line connections where you need the special tool, filler spout and vent hose clamps, and two pinch clamps on breathers on top of tank. It took me less than an hour, by myself, with half a tank of gas to drop it. I did get a neighbor to help me carry it into the garage though. I could not imagine taking the bed off to get to it! That has to be way more work!
 
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Old 12-14-2010, 04:23 PM
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In a supercrew it's under the cab.

Originally Posted by glc
You can get at the fuel pump without dropping the tank if you lift the bed. It's not all that hard.

Check the easier stuff first, like the inertia switch and the fuel pump relay.
 


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