Loss of Power on hills

[4x4grey88]

I recently have been having a loss of power on my 1988 (4.0L) 4x4.

It only happens when I am driving up a hill or grade. It will down shift but still it does not have the power that it once had. I have recently replaced the TPS, Crank sensor, spark plugs, wires, distributor cap and coil.

There is a idle motor probe in the side of the carberator (for the life of me, I can't remember the name of it though) that I removed and cleaned with carb cleaner and returned it to the slot. I am thinking that that might be my problem, but I am not sure. After cleaning it I read that much care should be takin not to move that part around to much. I don't remember moving it around too much but who knows. I looked for a loose or broken vacuum line but found none.

The idle is a bit rough but runs okay.. high idle at start up (revs then drops to normal).

I tried the computer reset but still the problem.


Does anyone have suggestions?????

[AlohaBra]

Originally Posted by 4x4grey88

I recently have been having a loss of power on my 1988 (4.0L) 4x4.

It only happens when I am driving up a hill or grade. It will down shift but still it does not have the power that it once had. I have recently replaced the TPS, Crank sensor, spark plugs, wires, distributor cap and coil.

There is a idle motor probe in the side of the carberator (for the life of me, I can't remember the name of it though) that I removed and cleaned with carb cleaner and returned it to the slot. I am thinking that that might be my problem, but I am not sure. After cleaning it I read that much care should be takin not to move that part around to much. I don't remember moving it around too much but who knows. I looked for a loose or broken vacuum line but found none.

The idle is a bit rough but runs okay.. high idle at start up (revs then drops to normal).

I tried the computer reset but still the problem.


Does anyone have suggestions?????

88...is kinda old...no offense..
How many miles?? Mine is a 97...with 125K but with fuel injectors...

used to be a mechanic tho....
How about clogged exhaust or clogged Cat (catalytic convertor)?
How about a vacuum test on engine while driving?
Other checks you might consider are compression test and timing chain stretch.

[Saudade]

HEY THERE! Mine's an '88!

4x4: Did you adjust the TPS to specs when you replaced it?

[bracketshark]

Have you changed the fuel filter? Might want to check fuel pressure also.

[4x4grey88]

Originally Posted by bracketshark

Have you changed the fuel filter? Might want to check fuel pressure also.

Has a GOOD FILTER. Just replaced the fuel injectors too

[4x4grey88]

Originally Posted by Saudade

HEY THERE! Mine's an '88!

4x4: Did you adjust the TPS to specs when you replaced it?

Adjusted it as per the chiltons manual.

I got the correct voltage.

[89ltd]

the 88 has fuel injection as well, I think he was referring to the throttle body.

[Saudade]

The FSM says it should be .2 volts for an auto trans fully closed.

A manual trans should read 4.6-4.7v wide open.

[mrbill3]

Have you changed to larger tires recently?