Hello,
I have a 1986 Ford Ranger 2.9 Manual that I am having an issue with. I am hoping someone could possibly point me in the right direction. The truck starts and runs fine. It will run great all day as long as I am under 45 mph and don’t high rev it. If I go up a hill and the rpms go up, it starts to jerk. It loses power, jerks and goes back to normal annd jerks again until I reach a flat area or until I shift to lower the rpms. If I am on the highway and go 55 or more on flat land, it’s fine. I can avoid the jerking if increase speed before the hill and just lay off the gas and decrease speed until the top but I don’t like letting my speed drop to 40 mph in a 55. Any help would be appreciated. Thank you!

 

On flat roads when you rev hard does your gas pedal react accordingly and pick up the speed instantly? If you ever experienced rev only but your car doesn't pick up the appropriate speed, it can be a sign of slipping clutch.

 

Two things you can easily check,

1. clutch master cyl fluid level
2.clutch pedal free ply ,(how far down clutch pedal goes before you feel resistance)

If no free ply, clutch cannot fully apply and will slip when under load . If this condition goes on long enough it can wipe out the clutch disc requiring clutch assy replacement.

 

it does, if I hit the pedal it goes no problem. It happens when I rev high and don’t shift. It only cuts out when the rpms go up.

 

I don’t feel any slipping of the clutch at all. Its shifts through all the gears no problem. It’s runs and goes down the road no problem. But If I am driving down the road and the rpms go up and I don’t shift to bring the rpms down it starts to jerk.

 

Some models have what is called a "rev (Revolution-engine speed) limiter" to prevent engine over speeding.

 

Diagnostic Routines index page shown above. Download Diagnostic-Routines.pdf below.
Pinpoint Tests index page shown below.

 

Michelene /Driver,

Were you able to select the condition closest to the problem with your vehicle and were you able to correct it ?

 

Been a while for me. Had an 83 & 88 Ranger. I'd start with fuel filters if you haven't done so. Being a 1986, you have 2 fuel pumps and 2 fuel filters. There is a low pressure pump in the tank that feeds the high pressure pump on the frame rail. Along the frame rail is a cannister filter for the low pressure pump and a filter just before the high pressure pump on the frame rail. All located on the inside rail under the drivers side most people forget about the low pressure cannister filter.

 

Hey ,,,,,,,,,,,,,Use Common Sense,

Glad to see you back, missed ya !