89 f150 5.0 fuel problems
Asked by Kevin Jul 26, 2016 at 11:07 PM about the 1989 Ford F-150 XLT Lariat Extended Cab LB
Question type: Maintenance & Repair
I bought a 89 f150 cheap from a dealership had no
problems for 6 months, then all of the sudden it broke
down on the highway I was pushing the gas and it was
slowing down when I pressed it. I've replaced the fuel
injectors, fuel filter, rear fuel tank, fuel pump, all relays, new
spark plugs and wires, timing chain and the motor still isn't
getting fuel. My diagnostic tester bit the dust recently and
can't figure it out. Don't really wanna buy a new tester,
could reall
7 Answers
If it is fuel injected, did you check the pressure with a gauge at the rail? If the pressure at the rail is low or non existent, check backward.
My husband's '91 turned out to be the "brain".
There's no pressure at all coming from the fuel pump, I might have to check the brain
You'll need electronic equipment to check the PCM. Check for power to the fuel pump with key on.
MrBlueOval answered 7 years ago
Ford have had numerous problems with their dual fuel tank switches so if you have dual tanks, check that out. Otherwise maybe the PCM but you'll need a code reader or scanner to check that. Good Luck, Kenny/MrBlueOval
If you are getting zero pressure from the pump, check and see if voltage is being supplied to it.
I have 3 ford trucks one f250 and 2 f150 ..years 1989,90,96.all have the 5.0 V8.my 1990 died on me so I checked th fuel pressure and it was 0.Changed the relay but still didn't fix the problem. Decided to put a new fuel pump and still didn't work. So I called a friend who has more experience with these trucks and he installed a hot wire from the ignition switch wire to the fuel pump hot wire and the truck started rite up.He said that I need to change the computer you can purchase a rebuilt one on Ebay for a reasonable price. I haven't changed mine yet, it's been over 2 years and it's running fine with the hot wire. I don't use the truck very much but eventually I hope to change the computer. Hope this can help someone out there.
