I'm pulling out my hair with my new 86!!

[lateferdinner]

I bought an 86 ranger a few weeks back thinking it would make a great little truck for hauling stuff around. And it has been. I like the little guy a lot but it has a little problem. When I get on it hard or am deep in the throttle on hills, it bucks a couple times then runs out smooth again. I thought when I first got it maybe a plugged fuel filter, so I gave it a full tune up. Didn't fix it. I replaced the fuel regulator. Didn't fix it. I checked all the vacuum lines and they look great. I also ran some injector cleaner through it and that didn't change anything. Has anyone else ran into this problem or have any ideas what it could be? Oh yeah, the specs.... It's a 2.9, 5 speed, 2wd. Any help would be greatly appreciated.

[Mike J.]

Possible bad TPS sensor. With ignition OFF, disconnect the sensor, put an analog ohm meter to the center pin and one of the edge pins. Operate the throttle. Depending upon what side of the sensor, you'll read high ohms that will drop to almost zero or almost zero ohms that will rise. The direction doesn't matter, the ohm meter needle movement should be smooth with no sudden jumps. If I'm right, there will be an drop towards the high side of the resistance.

[lateferdinner]

I checked out my TPS today and that's not it. My ohmmeter was silky smooth as I ran the throttle. Thank you very much for that piece of info. Do you have any other ideas on what it could be?

[kdr358]

whens the last tune-up?

[lateferdinner]

I just did that like a week ago... I did everything too... fuel filter, oil + filter, air filter, wires, plugs, and cap + rotor.