Veh : 1988 Cherokee Larado 570,000 km
Engine : 4.0l (Renix)
Trans : Auto
TC : NP-242

Symptom :
There is a jerk or stumble at highway speeds. Between 100 and 110 kph (I wont go higher), 2000 and 2200 RPM. It seems to be getting lower and lower in speed when this happens now. The idle is also slighly rough, and there is a lack of power when going up hills.

I have replaced :

Cap & Rotor
Wires
Plugs

I checked the replaced components and all was good. The plugs were golden as per a well running engine. Found that the Rear Main seal is leaking, as well as a puddle of oil in the bottom of the dist.

I suspect :

Crank Sensor ?
Map Sensor ?
Cam sensor ?
Maybe Coil ?

 

No cam sensor.

What position do you have the Power/Comfort trans switch in? If in Power, is it lit up?

Adjust your TV cable.

https://www.cherokeeforum.com/f2/free-quick-fix-41821/

Click on the pink link in my signature and do #1, 2, 3, and 4.

 

I have upgraded the grounds using 00 welding ground cable.

Today I will adjust the TV cable, Check all Connections, Clean them all (including the coil), and adjust the TPS.

I will report back what I find, hopefuly with pictures.

I do have a hard shifting between 1 - 2, 2 - 3, and 3 - 4. Its not SUPER hard, but its noticeable. And It does have the power/comfort switch. Its always in the comfort setting, unless Im hitting a big hill, then I switch to power so that the transmission down shifts sooner.

 

Leave it in Power mode. You're not saving gas in Comfort.

You've upgraded the ground, but did you refresh the others in the write-up?

 

The power setting is better for the transmission, leave it there. Have you checked the fuel pressure?

 

Iv replaced all of the grounds on the engine... There were 5 I believe.

Theres no difference between Comfort and Power? I believe Iv read that the newer models of the Cherokee didnt come with comfort, its always in power mode... Maybe this is why? Maybe Comfort mode is a problem??

I have checked for fuel pressure, how ever I will check again, as well as replace the filter.

 

Did you clean the dipstick tube stud ground and connections?

Yes, there is a difference in Power and Comfort modes. Comfort mode sucks and causes weird shifting. They eliminated it in mid 91 or so.

I bypass the switch completely because they are prone to failure and default to the crappy Comfort mode when they do.