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!