89 f150

Ok I have a 1989 F150. It has a 300 straight 6 (4.9). I read some posts on here the other night of people having the same problems as me but can't find them now. Anyway I just got this truck a couple of weeks ago and I've been driving it to work every day with no problems, until the other day. I was sitting at a stop light and the truck just started sputtering and quit. I had put 11 gal of gas in it 112 miles before this happened. (I know this because I was measuring the milage for the first time to see what I was getting.) Well my gas gauge was reading 3/8 of a tank at the time but I thought that maybe it was screwed up. I pushed the truck off the road, and got gas out of the back tank (which does not work) and put it in the front tank. The truck started and ran fine to the gas station. I left it running and pumped $20 in it, but when I got in it to drive off it started sputtering again and quit. I let it sit for a few and tried to start it, but it just kept turning over and wouldn't hit. Well I left it there over night and went back and it fired up on the first crank. I've replaced the fuel filter on the frame rail since then and the plugs. I haven't put but maybe 20 miles on it since then, but the truck still sputters and tries to quit when ever I stop at a light or a sign. When I take off it jumps like it gets gas for a second and then it doesn't. Could it be the ICM??? I'm just looking for a solution.. The temprature gauge doesn't work either..I mention this because in the thread that I was reading the other night that sounded just like mine they said there temp gauge wasn't working either. When I rev the truck up it back fires a little when the motor is slowing back down. The weirdest part is it does not do this all the time. Please HELP if possible. Truck only has 73,000 original miles.. I love this truck have to get it running right.. Truck shows no bad codes on it..

shawnsf150

timeing off? spark wire arcing some were? codes?

Lpartsmonkey@aol.com

Check your MAP sensor, next time it stalls and won't restart unplug the electrical connector to the MAP (on top of the evap case if air coonditioned, 1 vacuum line, 1 electrical connector). I had one that would only fire off choke cleaner and the fuel injector pulse was very weak, turned out the MAP sensor cured it.

Just call me Sean

iTrader: (1)

Sounds like the fuel pump. Better check the pressure, and check for codes.

89 f150

When I had it put on the computer there were two codes that came up, but the person that ran the test on it said that they were normal codes and that nothing else came up. I wrote down the code numbers but I can't find them now. I will post them as soon as I find them. I think that one of them was 77 though. I could be wrong about that. I'll try a map sensor also. Keep the ideas coming, I need all the help that I can get.

ymeski56

ditto!

'89Lariat

Code 77 = operator error. It means you didn't follow some of the the test steps, such as turning the steering wheel, stomping on the brake pedal, or gunning the engine.

As for it being a fuel pump, I'm pretty sure you can check fuel pressure right at the fuel rail, there's a little valve stem right there. I don't remember the normal pressure range, though.

jacked f150

hey is the engine misfiring at all?

ymeski56

50-55 psi. And I shouldn't loose pressure for the first 5 minutes after shut down. Someone please correct me re: bleed down info if needed, but pressure while running is correct.

RiverMarine

Im having alot of the same trouble on my 91 f-150 4x4 4.9efi, I have changed plugs,wires,rotor button,dis.cap,fule filter on the frame,it feels like it loads up idles rough,will not take fule then stalls in 15-20 minutes it will start and run. Help