Questions and Answers
Ford F-150 Lacks Power
Q. I have a 1986 F-150 six cylinder, 300 in engine. The thing runs great on the hi-way. The trouble I'm having is that is hard on gas (about 13 miles to a gallon). I tried to take it to have it checked but the guy said he couldn't find the plug to hook up to his scanner or computer, and he would have to check each input separately.
It has an automatic transmission, carburetor, and about 165,000 miles.
My problem with this truck is that:
1. I think it uses to much gas for being a 6 cyl., Am I wrong?
2. THE MAJOR PROBLEM, is that it does not have any power when I take off. Popular mechanics CD. says it might be taking off in second gear. When I start up and get to about 5 mph. it shifts, then again at around 25 and then again at about 45. Which seems to me like it is alright. I can drop it down into low, manually, and I get more power, but isn't this low, low for just binds or does it have to start in this low gear? HELP!A. The transmission in that truck should start out in low, then shift up. If it is starting in second gear, I think the cause of the problem can be traced to the valve body. Some had a two piece 1-2 valve and some had a one piece 1-2 valve. The only way to know for sure is to take the valve body apart and look at it. There is no external way to identify them. A transmission shop would have to do a pressure test to see if this valve is working correctly. It is also possible the Throttle Valve Cable is too tight.
As for the milage problem, It is possible the carburetor is out of adjustment and running rich. That has an Electronically Controlled Carburetors and the mixture is controlled by a Feedback Solenoid that may be going bad or has some partially clogged passages. It's also possible the ignition timing is off and needs to be readjusted. This could also account for the low power on take off.
This fuel system was a transition from carburetors to Electronic Fuel Injection and were very finicky animals. Many a Technician were happy when they were replaced by EFI.
Additional Information provided courtesy of ALLDATA
