I have a 93 f-150 with a 5.0. The problem comes and goes. The low range light will light up and the engine will surge between 500 to 1000 RPM. If i take it pass 1000 rpm it has very little power. No rime or reason as to when it does this.

Things that I have done
1. took the moter off the transfer case and it is in 2H.
2. Disconnected the plug to the motor on the transfer case
3. change the fuel filter
4. replaced fuel pumps (1 was not working and replaced the other because I had the bed off.)
5. Replaced the fuel regulator

Anyone have an Idea as to what to look at next.


thanks

 

Always happen that way? low range light comes on and motor surges?

Or can and do the problems ever occur separate from each other?

Did unplugging the shift motor keep the problem from happening, only to return when you plugged it back in?

Any chance you got some wires pinched when you put the box back on?

Not necessarily wires caught between the frame and box but maybe up inside the frame rail, pinched by a bed bolt nut as you tightened one down and didn't notice?

The light and the surging happening at the same time each time without fail would suggest a wiring issue.

 

Danr1

Everything was done after this started. Nothing has helped. I looked at the wires but will look again.