got in this morning and the battery was near dead. it still had power to keep moving the starter slowly. i knew for a while that i was gonna need a battery at some point. it was a 525 CCA, so basically it was crap. Anywho, i went to walmart and bought a 900 CCA battery (word of advise, don't evvvvver buy batteries at walmart, but that's another story). the truck sat without a battery for about an hour. installed the battery. tried to crank it, and for about 3 seconds it made the same effort as it did with the old battery. but then it started turning over, but wouldn't crank. it would almost crank so i gave it gas and it turned over, but when i let go of the gas, it died again. i did this a couple of times and kept my foot in to 1500 rpm for about 10 seconds and when i let off the gas, it started running semi-normal. it had a miss. the check engine light never came on.
but here's the weird part, there was quite a bit of smoke coming out of the tailpipe. the weather was about 40-45 degrees.
so, i drove it around a bit, shut it off in a parking lot, and it turned over just fine.
bear in mind, i took it to Washington DC yesterday, a 400 mile or so trip. it performed 200% and asked for more.

my theory is:
stage 1 - i parked it last night, temperature drops, cylinder walls condensate, mildly hydralocks the motor, makes it hard for the battery to turn over, almost kills the battery.
stage 2 - computer resets, so it doesn't wanna put out spark for a half a minute or so.
stage 3 - vehicle turns over and pushes out the rich fuel mixture and cylinder wall moisture, travels it through the exhaust pipes, and makes a whole bunch of smoke that smells weird.
also bear in mind that my "stock" catalytic converter is "high flow" if you know what i mean. so, combined with a flowmaster 40 there's plenty of opportunity for condensation.
anybody else has any sensible input? because, i'm barely buying my own story.

 

Mine does the same thing you described if it stalls while starting, which happens about once a week because I have a push button start. grayish smoke and smells a bit funky only for a few seconds though. I say its nothing to worry about.

 

my roomates cherokee and mine as well have the same problem, the old comanche did the same. on the throttle body there is an electronic insert on the very front. im pretty sure its called the throttle position sensor (TPS), replace that and it should clear your problem.

 

yea, but why all of a sudden? i mean, technically, it was the first time that i drove this jeep for over 400 miles in one day. but i doubt that it would cause something.

 

Well this is just a guess. But did you hollow out your cat? If you did and your jeep is a 97+ with a (down stream) o2 sensor then its not a guess any more. On the newer years you need a working cat and all o2 sensors working or your jeep will run like crap. Your o2 sensors tell the computer how your running and adjust air and fuel to run meeting government specks. If these things send the wrong signal you will run to rich or lean or it will make it breath through a straw. Basically if your jeep runs it won't run well or long!

 

Sensors are funny the TPS can also starve your jeep along with a MAP. If any of these are not working wright you can test it by letting it run and unplugging them one at a time. If it runs better with one unplugged replace it. Jeeps are like kids to know them well and for them to have a long fulfilling life you have to spend time with them and through gobs on money at them if you want them to grow.

 

Cherokee's are heavily dependent on their crank sensor and oxygen sensors. Check these very well. And you confuse the crap out of people when you say things like " it started turning over, but wouldn't crank" thats the same thing!!! What you mean to say is "it cranks but wont start" or "it turns over but won't fire"

 

Like anything else, there is never a history of it happening, until it happens. My neighbors did that once or twice.

 

Not true, the downstream O2 just monitors the cat and has nothing to do with rich/lean fuel management.....that's done by the upstream O2. '96+ have downstream O2's.

 

that's what we say in the army usually.

 

hey but it runs fine now, as if nothing was ever wrong. it does idle low and has a slight miss, but that's been going on since i changed the plugs. i think i need new wires. my mother in law had owned this truck since day one, and when I asked her, she told me that she doesn't remember a tuneup.

 

oh dang dude, you were right. i hadn't read my own post, i did make it quite confusing with all of turning over and cranking. my apologies.

 

oh man, that is not good. put some kind of cleaner in the oil and drive around for an hour or so before you change your oil next so it gets some of hte crap out from stuff not being done right

 

just did that two weeks ago. if you go to my pictures, you can see some of the junk i had to deal with.

 

No sweat! More people do it than you know!!!!!!!! It's just confusing sometimes!!!