Acceleration problems

I have a '99 F-150, 6 cyl, ext cab, 87,000 miles. About a year ago, I started to have problems with acceleration. At first it just hesitated, then it completely lost power on the highway one day. The engine didn't die, it just wouldn't accelerate. At that time, I had the fuel injectors cleaned, fuel filter and pump replaced, and regular maint like spark plug and wire change and O2 sensors replaced. The truck ran fine for a month then started same prob again. Second visit, the mech said the injectors were caked again, filter was gross. He changed injectors, filter, and pump again. He also took out the tank and cleaned it. After about $1k the truck ran fine....for a year. Last month (March) started to have same problems again! Cleaned fuel injectors, changed fuel filter and pump again, also changed plugs and wires again. Ran fine for another month...It's in the shop again (April) for same problem!!!! Someone please help.

get your gas somewhere else, and add some antifunicide to your gas.

We've moved to another state since probs last year. Are there that many stations with bad gas? Also, where can I get this antifungicide and what will it do?

Are you buying the same brand of gas?

We've always used reg unleaded. The mech that has it now says that he thinks it has something to do with the transmission. I don't think I buy that. According to the repair manual, it says its all in the fuel system.

not type> what brand?? Gulf, Texaco, etc....

Don't know if this helps, but a common problem of the 4.2L engines in the '99 F-150's is the restriction of the EGR passages in the lower intake manifold.

We usually fill it at the station on our military base, otherwise we try to use Mobil or Amoco. How common of a problem is it? Do the symptoms I described sound like that could be it? Would it re-occur? Thanks for your time everyone.

I know it sounds dumb, but it's probably an electronic tranny if it's a 1999, so do something simple as check the fuse for your tranny, or have someone qualified look at all that wiring. good luck with it

ok, wiring will not effect the injectors in caking up. Now low fuel flow would possibly, check you fuel pressure and see if that is normal.

Sell it. Buy a Pinto.

Have you checked your trottle Position Sensor(TPS). After all the work you had done to it they probably have. I had almost the same problem on my 92 F150. I also was told to flush my injectors and so on. A $40.00 part fixed it.