Hi, I'm brand new to CF so I apologize if I didn't post this in the correct area.
So, about two months ago I bought a 1990 cherokee. (Automatic,
220,000 miles.) The head gasket was clearly going out, so I said whatever and did it myself. Well.. after that, I've been having all sorts of issues. It idles around 500 but will go up to 1,000+ and then back down to even 250 and then back up again. I got rid of the overheating issue, but it just doesn't seem like it wants to shift. If I drive in manual 1 /2 and 3rd it runs fine. But as soon as it's in drive it's very sluggish and lacks power. It also makes a sucking noise from what seems to be the intake side of the block, although I just did a new manifold gasket.
almost feels as if it's a fuel issue. I replaced the filter yesterday and it made no difference. I have a new pump, but I don't want to do the pump if it's not going to fix it. At least not right now. (I work 7 days a week 12 hours right now. But if anyone could give me some direction as to where this issue is coming from that would be awesome. I'll include a list of things I've done so far.

Head gasket
valve cover gasket
Water pump
Inlet heater tube
Thermostat
Thermostat housing
Fan clutch
Exhaust / intake manifold gasket
All Heater hoses
Lower radiator hose
Fuel filter
battery
Battery terminals
cleaned IAC thoroughly
cleaned TPS thoroughly
new throttle cable
adjusted Kick-down cable
cleaned throttle bottle thoroughly
new vacuum hoses

 

Check your fuel pressure and see if it's in spec - if not, you should go ahead with the new pump.

Did you check out cruiser54's site for information? It's just www.cruiser54.com and has a wealth of info on your Renix Jeep.

If that doesn't help, I'd PM cruiser54 if he doesn't jump in on this thread.