RE: Ask the Car Guy @socky May 8
Actually my 2000 Ford f-150 has a fuel problem. If I remove the breather and squirt fuel in it'll run a few seconds, I removed the fuel pump and with power connected it runs and pumps, when attached it runs for a couple of seconds n shuts off, as it should.
I had the same problem a week ago, removed pump n checked, put it back on and it worked! Only this time reinstalling don't help. I tried tapping on it, checked the impact sensor...not sure how to check relays, but it coming on for a bit when the key is turned shows it works, I guess? It don't even try to crank, no sputter or anything unless I squirt fuel into the breather opening.
It appears to flow freely through the filter. I'm bamfoozled, not sure how to check all the relays and things. Seems there are an overwhelming amount of modules, relays and sensors that could cause problems with the pump.
Any help is appreciated.
I see a cheap code reader at harbor freight for 70 bucks, could this help diagnose my problem?
Check the fuel pump driver module. It is pretty common for it to go bad. Search YouTube for “fuel pump driver module”.
It seems my truck don't have one, I searched everywhere it was supposed to be. From what I read the way I understand it, the two tube return type pumps don't have one, they have a pressure regulator instead. It's a Dec 99, 6 cyl two wheel drive regular cab.
I bypassed the relay and hear hissing at the engine when power is applied, but haven't tried starting it it while doing this. i tried afterwards thinking some fuel should be available for a few secons, but nothing. If I spray fuel into the intake it will start for a couple seconds.
I can't afford to buy a part to find it's something else.
The thing that gets me is, if it's supposed to constantly run on the dual return, why does it shut off after a second, but run as long as manually applying power?
On most vehicles, it is normal for the fuel pump to turn on for a couple seconds and then shut off until the engine starts. The fuel pressure will build up and stay pressurized. I think it is a safety mechanism. You wouldn't want the fuel to continue to pump in an emergency situation like a fire or crash when the engine is no longer running. I would have the fuel pressure checked. Most shops have the capability or you can buy a fuel pressure tester. A fuel pump can come on and you could still not have enough pressure for various causes. The fuel pickup is broken, the pump is weak. the filter is clogged, the fuel regulator is malfunctioning. If you had the fuel pressure tested, you can rule out all the issues with fuel supply. then you can look somewhere else. you should be getting a signal from the computer that drives the relay. You may also have a fuel shutoff relay that could be causing the issue, but before you start chasing trons, make sure you have the correct fuel pressure.
Something is closing the line or redirecting the fuel. I bypassed the relay, can hear a hissing at the rear of the engine. Pump seems to have very good pressure.
Code reader shows no codes found, which is weird.
I can not blindly replace components. I know thats what they would do at a shop, start replacing stuff till they hit the problem, then say it needed all that.
Doesn't make since that I spray fuel in n it cranks but bypass the relay where the pump has to run and it doesn't even try to crank. Seems if the pressure was low it would at least try, but it sounds like it gets absolutely no fuel, unless I spray it in.
I wonder if the pressure regulator can close the fuel off or redirect back to the tank? If so, how could I test without complex equipment?
Sorry if I sound aggravated, I use the truck for a living, I'm so screwed.