'92 XLT 4.0 tune-up?
Ok, so I have been meaning to tune-up my wife's '92 XLT since last Fall (when I successfully tuned up the Jeep and she recognized that I could be trusted with her baby). Now that the weather is better around here, I was all set to get the parts. Then this week, the engine started sputtering and hesitating on me. When I shifted to 2nd or 3rd, it would lose power and I'd have to rev it up and/or downshift to get it moving. Sitting at a light, the idle would be fine for a little while, but if it was a long light, then the RPMs would drop to under 750 and it would threaten to stall out unless I revved it up. Getting home, I let it idle for a few minutes, and it was fine. Didn't sound rough at all. Maybe it needed to warm up, I don't know.
So, whaddya think?
Fouled plug? Wire? Fuel filter? Bad gas? Catalytic converter?
Searching here said any/all of those things.
I got a list of tune-up parts from Auto Zone. I wondered if you guys could comment, let me know if these would be ok, or if my model was picky about plugs or wires (I know some are).
Also, I bought a bottle of Lucas fuel treatment to try out.
Plugs - Autolite Double APP105
Wireset - Duralast 4144
Fuel filter - AZ Filters FF745
Air filter - STP SA5058
Also maybe a PCV valve.
Coil seems ok, but I'll test it.