Hi everybody.
I have a 1995 F 150 extended cab, 5 liter, 8 cylindar, 2 wheel drive with air. The problem I'm having is VERY intermittant and began May 14, 2005. Initally the truck did not want to accelerate up hill, but it would accelerate in reverse just fine. It also acted up primairly at night. Over the next few weeks the problem was still intermittant but persistant. The check engine light came on, code: non specific lean. The truck will drive fine then for no apparant reason it looses "power", but idles fine. I have to shift into neutral, pull of the road, turn it off, sit a few minutes, turn it back on and continue on my way. If I push down on the accelerator when this happens the truck continues to loose power, but does not stall or die, it has a steady loss of power and will start "popping". After shutting the truck off what ever is going on resets itself, the truck runs fine until next time. I have set the trip meter between events, there is no set pattern, just random and persistant. The Ignition Control Module and Mass Air Flow Sensors have been replaced. Since replacing the latter, I have been able to temporairly "Power Out" of the situation causing the truck to go into passing gear. However this is not always the case. In addition when this occurs now, the check engine light does not come on. The transmission was totally rebulit after blowing apart all over the highway last August. This truck is very special to me as it was my Dad's. He gave it to me just two weeks before he died. I would like to keep it as long as possible, as this is all I have that was his. The truck had given me no problems until recently. It has approximately 133,000 miles on it.
Any help would be greatly appreciated.
Deb

 

Sounds like a fuel system problem , I would suggest you get a pressure gauge on it an see what your reading ,, I had one F150 that I ran around in for 2 days with a pressure gauge attached to the fuel rail an every time it did it the rail pressure would start dropping, finally replace high pressue pump an it took care of it,,, Also does the truck have Dual tanks ???? I've had the switiching valve go bad on them ,, kinda acted the same way ,, start lossing poweryopu could mat the pedal to the floor an it would go to popping thru the intake,, hope this helps

 

Maybe fuel pump? Do as ramrod suggested check pressure and T/S from there.

 

Fuel filter might be partially plugged too. With the extra load of running the lights at night, it might make it more noticable.
Octane

 

NAWWWWWWWW, running the lites shouldnt put that much of a load on the ole girl , unless u got enough lites to lite up a baseball field at nite. So I think you scratch the lit idea !!!!! Sorry

 

I'm having almost the identical problem on a 94 F150 4x4 super cab with dual tanks. There is no rhyme or reason, so the night factor "darn that truck!" mentions is not a factor for me. I've only had the truck 5 months, and because of the problem have only put about 500 miles on it. In fact, I think that's why the last owner sold it. He replaced the Mass Air Flow Sensor, and my dealer has replaced it twice now since I owned it. But this still has not corrected the problem. Three new sensors in 6 months, I think it's time to move onto something else. Unlike the poster's truck, mine only has 59,000 miles, and has had meticulous dealer only maintenance. In fact, it's sitting at the dealer now.

 

How long has it been since the fuel filter was changed?

 

SA, I have a 86 F-150 with identical problems. I replaced the MAP sensor. Still haveing problems. A friend looked at it and sprayed cleaning fluid to try and pin point what sounded like an air leak. It appears that I have a manifold leak which causes the MAP sensor to get false readings. Don't know if this helps you at all but we are going to try replaceing the gaskets and see how it works.
Later
Z

 

Is it possible that you have bad fuel or moisture in one or both of your tanks? If you have moisture in your fuel, your engine will act in much the same way. Put some Heat in your tanks. Could be a cheap fix.