Deloy3

I have a 93zj and when I hit the gas it just doesn't have the power it used to have. I've had it for about 5-6 years now and never had a problem. It sat for about 2 years total and I replaced the head gasket and valve cover gasket and then put it back on the road and now feels like no power while I'm driving. Once in a while while driving on the highway it won't shift into overdrive either. It doesn't down shift while going up hills. All these problems just started when I put it back on the road. Any help would be greatly appreciated. Thanks.

kjc

I'd suggest you adjust your TV cable.. It's simple to do and if it's not correct, it can cause poor shifting and possibly even damage to the transmission.
*With engine off, press the 'D-shaped' release button and push the cable adjuster all the way back into the housing (see pic) Release the button. Now grab the throttle linkage on the carb and twist it to WOT position. You'll hear the adjuster 'ratchet' as it self-adjusts. Easy as that.
*Test drive it to see if it seems to have more power now. It should downshift normally and your OD should work at hiway speed. Hope it was just something simple.

Deloy3

I adjusted the tv cable a week ago but I did it wrong. Now that you explained it and I did it correct I'm hoping that fixes the issue. I just changed my spark plug wires thinking maybe that would help. But now the cable is adjusted while the throttle was wide open so I'm hoping this works. Thank you for your help.

ol"blue

Sounds like you have bad gas in it from sitting for so long.
You stated it sat for 2 years. You need to check all the wiring for rodent damage. I had a '97 ZJ that wouldn't start one day. Upon inspection, a squirrel had chewed through some wires in the engine harness, and 2 of the spark plug wires. My son found another harness from pick-a-part for 20 and once installed it fired right up.
It might not be your problem, but it's worth a try.
If it's a V8, the pre '95 V8's had EGR, and they can cause performance issues when the passages get plugged up, or the lines or solenoids become disconnected. Also their vacuum lines can come loose, or become cracked, causing a lean condition.

Deloy3

I have the inline 6 in it. I checked all the wires when I had the top end apart before I put it all hack together and everything looked good. I had my buddy with me when I did it who was a mechanic for 30+ years just I know I was doing everything correctly. Adjusting the TV cable did help, it shifted into overdrive last night on my way home from work. Only issue with that now is for every gear it shifts at about 2250rpm, no higher, no lower. And as soon as ur hits about 43mph, it shifts into OD and it feels like its bogging out, no power after that. It does have the power back in 1st-4th gear though, but like I said, only revs to about 2250rpm. I've seafoamed the fuel system and put gas additives in the tank when I put it back on the road as well. Any other options you can think of? Possibly tranny issue?

Deloy3

And still no kickdown either. I put the pedal to the floor, and nothing.