Need experts on OLD trucks - 88 Ranger

[Josh P]

Thanks for the update.

 

[traveler]

Out of frustration and impatience, i went ahead and spliced in a 4-wire O2 sensor I had in my toolbox. It had two white wires, a black wire, and a grey one. The 3 wire plug had two white and a black. So I wired the two whites and the black one and ignored the grey one. The truck ran good, with no CEL for about 4 miles. They a CEL came on. The truck continued to run ok. I'm guessing it finally figured out I was using the wrong O2 sensor, or the bad splice job gave out. I haven't checked it as I came in to let the truck c (exhaust pipes) cool off before investigating. I'll order the correct O2 sensor from Ebay for 10 bucks and wire it in right and that should take care of the problem.
New problem however. Now that the truck is running smoothly, I can feel the other problems. It doesn't shift from 2nd to 3rd quickly enough. Resulting in the engine revving up between 2nd coming out, and third going in. I think its a valve body problem, as none of the gears are slipping once they are engaged. But again, I know more about the 4R70W than I do about the AODE that I think is in the Ranger. It could just be a broken spring in an accumulator valve. I've replaced those in a 4R70W before. I'll know more once the O2 problem is sorted out.

 

[Josh P]

The transmission is an a4ld. Check the transmission forum on the shifting issue.

 

[traveler]

Will do, thanks

 

[traveler]

Ok, I installed a new O2 sensor, correct for the truck. It runs fine other than a slightly rough idle. I think maybe the plugs fouled when it was running WAY rich with the bad O2 sensor. I've ordered a new vacuum modulator for the transmission and hope that fixes it. I'm not real sure it will but its cheaper and easier than pulling the valve body and it won't hurt to have a new one anyway.
The weird windows worked for a few minutes yesterday. Now they are back to working when the door is open but not when it is closed.
Also put a new striker plate bushing on the drivers door. The door closes snugly again.
Other than what I've listed it really is a nice truck for the age.

 

[Josh P]

Nice looking truck, it is in good shape. The wiring for the windows and door locks runs from the doors along the back side of the fenders up along the front of the engine bay.

 

[traveler]

I'll look into that tomorrow, thanks. I did just remember the one other thing that is irritating to me. The gas gauge doesn't work. All the other gauges work, just the gas gauge doesn't. Any thoughts on what the most likely problem is. I'm leaning toward sending unit, though I really hope I'm wrong. Don't wanna drop the tank.

I see you're from Phoenix. We're actually moving to that area this summer, sometime after school is out. (My wife works for a local high school)

 

[Josh P]

The bed pulls off easier than dropping the tank. The supply wire to the sending unit is 5V, jump the supply and return wire. If the gauge jumps to full there is a problem with the sending unit, if it doesn't move then it could be a wire or the sending unit, maybe a bad gas gauge. If you do drop the tank to test the sending unit, full is 10 ohms and empty is 73 ohms.
I've lived in Phoenix for 19 years, the lack of snow is why I stay.

 

[traveler]

I'll consider raising the bed. It does seem like more than a one man job though. Any idea where I might find the supply wire? I traced the bundle of wires from the tank, and didn't find any connectors that might lead to the dash. I did find a two wire connector that led up to the floor of the cab, under the seats. I assumed that was for the seat belt buzzer.

 

[Josh P]

I'll consider raising the bed. It does seem like more than a one man job though. Any idea where I might find the supply wire? I traced the bundle of wires from the tank, and didn't find any connectors that might lead to the dash. I did find a two wire connector that led up to the floor of the cab, under the seats. I assumed that was for the seat belt buzzer.

The power wire for the sending unit goes to the instrument voltage regulator in the dash. Common symptom of the IVR failing is all the gauges will fluctuate. An EVTM can be bought off ebay for under $20. It has all the wiring and vacuum diagrams needed for troubleshooting.