Cee's89XJ

Have 89 Cherokee 2dr Sport trying to revive after sat 7yrs. Replaced master cyl, O rings at injectors, plugs, wires, rotor, cap. Ran gas past fuel gauge light 2x, added fuel/injector cleaner.
Acceleration drops when past 1/4 throttle. Idles fine. Changed fuel filter, found gas milky color.
Guess need to drop and drain tank?
Suggestions on next step, best process to clear up fuel? TIA

dmoe69

I had similar trouble with my '88. About the same time sitting. I originally disconnected the fuel line from the filter, routed it to a can, and ran the fuel pump until it lost suction. Later, after installing a new fuel filter and new fuel injectors, I experienced bad engine stumbling above 2000 RPM. When I checked the fuel filter again, it was full of everything but fuel. My gas tank is encased in a factory skid plate and tow hitch. I opted not to remove it, but I regret that now. Turned out the suction filter had fallen off the fuel pump. When it lost suction there was still an inch or so of YUK in the bottom of the tank. After removing the fuel pump I was able to remove most of the junk in the bottom of the tank (and retrieve the suction filter). I opted to trash that set of fuel injectors for another set of remanufactured Volvo injectors (Bosch -746) and it has run really good ever since.
If I were to do it all over again, I would replace the fuel tank.

Jeepwalker

Check the front/rear intake hold down nuts for tightness. They work themselves loose. Could be you're losing vacuum.

The tanks are not that difficult to remove. Still a pain, but not as bad as some other vehicles I've done. You could run HEET through through the tank (isopropol alcohol), but it'll take more than a few bottles and tankfulls of gas if there's a fair amount of water in the tank. I've had water in the tank a few times and it can take a while to work a fair amount of it out.

If you want to get going on the project, best is to remove the tank and dump the fuel into a (non-black) 5-gal bucket ...so you can see the water. Once the water settles at the bottom you can pour the gas back off and re-use. If the gas is really old, I wouldn't re-use. Let the tank dry out and reinstall. Remove any water from the filter too. You might remove the filter too and carefully dump the gas into a clear container and see if you see any water (before removing the tank).

Good luck

Cee's89XJ

Drained tank thru schrader valve, new gas, still coughing over 12k RPM.

dmoe69

Very few good things happen in an XJ over 12K RPM . To continue down the possibility of bad fuel, my fuel injectors ate some bad stuff before I finally got good gas to them. They weren't spraying very good by then. With the assistance of a RENIX Engine Monitor (REM), I was able to see that the ECM was going over-range in short term fuel (ST), at which point the engine would start to stumble. In other words, the ECM believed the engine to be running very lean and it tried to give more fuel, but not enough fuel could be provided. My solution was to replace the fuel filter (again) and the fuel injectors.
Before going that route though, it would be prudent to do some diagnostic testing. A faulty TPS can also cause stumbling. It is a simple component to test. A good description of that process can be found here:

Renix TPS Adjustment | cruiser54

5-Speed

My vote is tps as well. Simple to check.