Ok so I have a '96 4.0L i6 and a about a month ago when I would go out to start the Jeep my battery would be dead (about 10 volts) so I would have to jump it, but while doing that after I got it to start in order to keep it going I would have to keep my foot on the gas. But shortly after that problem I started to get another problem, while driving down the road my Jeep would just cut out sort of my RPM's would drop to maybe 50-100 then it would come back like nothing ever happened and it did that no matter how warm it was or how much I mashed on the gas after it "cut-out".

So after getting scanned at autozone they said my IAC was bad or needed cleaning and my O2 sensor was bad, which I know its bad because I under estimated a puddle about a year ago and tore wires for it to shreds. I ended up just replacing the IAC just to be safe but it didn't fix the problem. I ended up having to get it towed to my Dad's house whose been a mechanic for years and a Jeep guy longer (he built 2 CJ7's from the ground up) so I called him a day later to find out what the deal was with the Jeep, come to find out I forgot to plug the MAP sensor back in. Picked it up from his house a few days later still doing the same thing.

After I barely made it home because it got worse the more I drove it I parked it in my drive way and there it's sat until about a week and a half ago, well after talking to my neighbor who has also been a mechanic for years had suggested to replace the fuel filter considering I could hear the fuel pump run when turning the key. After I did that I could feel a difference so thinking I might have fixed the problem I drove it up and down my street a few times and I could feel some hesitation in it like it was going to "cut-out" like before but I still didn't trust it any farther than up the street and back which was a good thing because after that I wouldn't idle for more than a minute or two and it would stall. Now it wont even start I will just crank and crank but not fire, I have however gotten it to start slightly with the pedal to the floor which would suggest a bad MAP sensor but that never threw a code when I had my Dad or my neighbor scaned it.

So as it sits now I have to jump it to try to get it to do anything (from cranking it so much) and it's a hit or miss getting to fire, and I have replaced the fuel filter and the IAC, back in September-ish I changed my ignition coil and CPS because my coil just died without warning.

I'm sorry for such a long story but I'm just trying to be as detailed as possible. I just cant throw parts at it and I'm look for advise on where to start. Any and all help is greatly appreciated and Thank You in advance.

 

Replace the alternator or at least have it checked. If it is not putting out sufficent voltage your batt. will always be dead and if your computer/sensors dont receive 14+ volts you will have all kinda problems.

 

Thank you for the input and I did forget to mention that I also had autozone test my charging system and my alt came back good but my regulator didn't, which has me worried because isn't it in the ECM?

 

Check all your alt connections and grounds and clean your terminals good. Chances are something is loose. If the ECU was bad then your may run into other issues and not a 10v issue. Chances are either the alt is bad, even is autozone checked it, or something is lose. Take a good old fashion work day on your ol girl and go to work on her and check everything

 

Did they test the battery?

 

I had a similar issue with my 94 lebaron... drove fine tool one day it would start bucking and eventually just shut off...most of the time while going around a corner at 60... we replaced everything: fuel pump, fuel filter, fuel and ignition relays, changed the all the sensors...everything in the way of fuel got changed... it now only runs for 15 minutes before ****ting the bed... that's why I now have my xj...the only conclusion we came to was the ecm went bad..

 

Yea they did test my battery and it came back good it's only maybe a year and a half old and under warranty for I think the next 5 years or so