cowboy44

My son just bought his first Jeep and we changed the fluids first thing. The first thing that went wrong was the oil filter for the year didn't thread on. I did some research and found that 1990 and prior engines used a metric threaded filter. I bought one and it worked. First clue something was off. We then did a basic tune up, cap, rotor, plugs, wires, fuel filter, and removed and cleaned the throttle body and idle air. The jeep ran good when we brought it home but we didn't know the history of it so we just wanted to make sure everything was good. We also replaced the battery, a bad starter, and installed a catalytic converter and tail pipe because they were missing. Two days after he started driving it he left the lights on the battery died and after we charged it it ran rough and rich. I tested and replaced the map, tps, mat, cps, and the dizzy. All it will do now is back fire a little out the intake. I have indexed the dizzy in every direction and nothing. Any help would be great thanks.

cowboy44

Also forgot checked all vacuum lines and replaced the coil. Gets great spark and fuel. Have not checked the pressure but has a good spray when the Schrader valve is depressed and also has flooded the engine. I am going to pull the timing cover tonight or tomorrow to check the cam and crank posituon. I'm at my wits end with this jeep.

Firestorm500

#1 plug wire should be oriented to 5 o'clock on the distributor cap in reference to how the distributor is installed on the engine. Double check your rotor position after doing this. At #1 TDC on the compression stroke the rotor should be pretty much right there.

It sounds like the distributor is not clocked/timed properly to the engine. These can be tricky at times, so triple check that first. Triple check your plug wire orientation while you're at it.

I don't see where you have done anything so far to cause the crank and cam orientation to change.

You sound pretty experienced and not afraid to chase a problem. But you have changed many things, apparently in batches. Getting back to the basics, remember an engine needs these things to run:

Fuel

Air

Spark

Compression

Timing

If it has those five things in the proper ratios, it will run. You've got the first three. Go back to the timing. If, after review, you are absolutely positively sure that's correct, do a compression check.