I have a 1990 F150 4X4 5.0L 5spd. Sometimes, mainly when the fuel gauge reads near 1/4 of a tank, the engine acts like it does not want to run. After a few seconds of this it will run fine with plenty of power. However, last saturday night after a short drive the engine behaved as though a cylinder was cutting out, at least to me. It sounds as though it was not running on all 8 cylinders and had no power. It was like this until today. I refilled with gas and put in a bottle of fuel system cleaner. The engine was worse than before. After a few miles I stopped at a light and the engine RPMs dropped to around 500, same as it has been. Then when I tried to leave it stalled and was difficult to refire. I have recently change, within 2 months, several parts. I started with a new K&N air intake, Granalti plug wires, and E3 diamond fire spark plugs. Everything ran as normal until saturday. Am wondering if it may be dropping a cylinder? On my way back to the house the engine ran seemingly fine, so I am not sure exactly what is going on here. I do not run the engine hard, all gauges (that work, the temp gauge is non functional but the engine does not seem to run hot) are well within the proper range, and the engine light is not on. Hoping someone can help me out here...

 

check your fuel pressure and see if maybe your fuel filter is clogged. ive had a clogged filter and if i didnt have much gas in it it would try to cut out and it got worse to the point where i would be driving and i let go of the gas the truck would drop in RPM's and cut out, and as you said, hard to refire

 

I agree with ^

Replacing the fuel filter on the frame rail would be the first thing I would do.

I don't think you have dropped a cylinder on your 302;
all 8 fuel injectors may not be getting enough fuel for the engine to run normal.

 

^^^^ x3

 

Just to update.... I put some fuel in (was on 1/4 tank) and since it has only started missin again for a split second. Rest of the time it runs like a champ. i will definatly change the fuel filter. Reckon it does not like only having 1/4 of a tank... or slightly less. Other than this issue and a oil leak I cannot seem to find, I love this truck.

 

The fuel pump is going out.

 

i would deffinantley check the voltage to the pump just to make sure its not wiring, and replace the filter anyways (its only 8 bucks and very simple)

 

I will definatly be changing the filter. I will check into other possible problems tommarow when I have the time. Thanks Ya'll for the help. Gotta take care of my baby

 

When the fuel level drops below 1/4 tank the fuel doesn't keep the pump cool anymore, and it starts to crap out.

 

Thank you. I am new to this stuff and was unsure. Never had a vehicle worth anything until I got this truck. Still learning how to work on it and understanding its little quirks