Warm Engine Missing, Intermittent

[fatoldcapt]

Okay, I need some suggestions before I go into the shop again (that is if it doesn't heal itself on it's own). I have a 94 YJ w/2.5L 4 banger. I just had a new head installed. New Plugs, Cap, Rotor, Coil, Fuel Filter, oxygen sensor. TPS Adjusted, throttle Body Cleaned. Cool Air Intake kit installed. The jeep runs fine until it gets warmed up. Then it "misses" (Studders)at acceleration. Mostly but not always around 2500 to 3000 rpms. It's acting as if the timing is off just a little so that it won't take the fule at those few occasions when this happens. Do any of you wise folks have an idea what to check next?
Aaron

[Don Davison]

do you still have the stock air intake

[fatoldcapt]

Most of it. (got the box) But it was doing this before I put on the Cool Air Intake. I kind of did all this in stages to see if any of it had effect. Of course I needed the Head and TPS Sensor work when it first went into the shop. The rest I did over a month or so as I had time. I could start all over by checking the plugs that were installed. aaron

[OU812]

I would check your catalytic converter. You just replaced your head so I am assuming you had problems before. These problems could have damaged your catalytic converter. When it heats up the catalyst expands and will nearly close of the exhaust. When it is warm it might idle ok but when you touch the throttle especially in neutral it will stumble.

[fatoldcapt]

Yeah, that's sort of what I was wondering too. I've heard about the converter causing this kind of malfunction. The head was letting a little water into the #1 cyl. That's why it was replaced. The Cat was processing the water along with rust. I'll remove the converter and rig a by-pass tube and see if I still have the trouble. New ones are expensive. Don't want to buy one if I don't need to.
Aaron