91 cherokee 4.0 Intermittent stumble when cold

I have a 1991 jeep cherokee with the 4.0. Just in the last 2 days when i started it in the morning soon after start the engine light would come on, if i tried driving with it on the jeep would stumble and sound as if the motor was missfiring/loosing fuel. If i shut the motor off and start it again the engine light is off and it runs just fine, unless it comes back on. It seems after the motor warms up theres not a problem.

I took it to the shop i work at and scanned it and got code 41 ( chargin system field wrong, or something along those lines) Recently i have done plugs cap and rotor, but no wires yet. I opened up the cap and there was some black goo on the carbon button/rotor where they contact, so i whiped that clean. Any ideas???

Yep...you better have the charging system looked at.

The alternator need to put out a decent voltage to charge the battery and to keep your Jeep running. Do you have a voltage gage in your factory instruments?

Yes i have a voltage guage, it seems to work just fine always around 12-14 volts. I dont remember what the voltage guage was doing while the engine light was on.

I was talking to someone earlier tonight and he was thinking mabey the computer isnt getting full voltage to it? Bad ground, wire something of the sorts??? I guess ill have to scan it tommorow when its doing it then i might get a bit more info.

Possible:

loose connection to alternator field
damaged wiring
loose ground at body connection from battery

Im gonna try those today, Yesterday i was scanning it after work, and sometime it would let me into the dataline, other times it would say no data, when i did get into dataline if i hit the gas it would click off the scanner and say no data. If i had KOEO it wouldnt matter what id do it would work just fine...... Ive got my dads manual to look at now tho, its one of a 94 jeep cherokee.... except its the big manual that dealerships use, so mabey ittl point me somewhere....