Stalling issues on 2002 Jeep Wrangler 4.0

fitch559

New Member
Original poster
Joined
Oct 9, 2020
Messages
6
Location
Fresno Ca
So I was having stalling problems and would read this forum religiously to try to resolve the issue. I seen a lot of people on here with the same or similar issue but all different answers. Here is the fix to my issue. I was having a bad stalling problem that would only happen at cold start regardless of what time of day or weather. I would start the jeep and would have to warm the jeep up for it to not stall. Coming up to any stop light after its first start of the day it would stall. Driving it around for ten minutes would do the trick and it wouldn't stall anymore. " I would even warm it up before driving it"

At first I thought it was a vacuum prob and checked everything and changed all the vacuum hose connectors.

I changed the crank sensor and connector and no go.

I changed the engine oil and plugs, properly gapping them to specs and no go.

I added the insulation kit as well thought It was a heatsoak prob.

I also changed out the temp sensor, pressure sensor, air temp sensor, map sensor, 02 sensors, throttle positioning sensor and still a no go. I cleaned my throttle body and put on a new gasket that was the first thing I did before replacing sensors and still nothing. Keep in mind all replacement parts were mopar so by now this is getting pretty expensive. Engine had good pressure so I was lost for words. The guy I bought it from said he changed out the transmission fluid recently and the oil looked good upon inspections and didnt smell burnt. I decided to drop the pan and check everything out and BINGO! The magnet was covered in gunk and the filter was super dark. Still had the original mopar gasket and filter so it was an easy change. I can guarantee this transmission oil has not been changed out since 2002. Cleaned everything up put everything back together and I have no more stalling problems. I should have went with my judgement instead of believing him from the get go. I even checked the tranny oil when I got home that day and thought man this looks ok and it was shifting fine why would this cause the stalling prob? I was wrong. I took it to a shop and they couldn't figure it out. I found out It was even low on fluid but was showing up ok. Ill do a second full flush shortly after I run it for a couple of weeks.

I changed out all my Dif oil, transfer oil and u joints.

Pinion seals, this jeep is literally running like a brand new jeep now.

I hope this helps someone and they dont make the same mistake as I did.

I assume changing the sensors helped out a lot as well because they were pretty worn and the guy had like three throttle body gaskets on it lol glad I caught that.

Long story short stalling engine, cold start, it might just need a tranny fluid change lol.

I also changed timing chain, water pump, thermostat, clutch fan, and plenty of other things unrelated to this issue just to do it cause I was bored. Everything I found on this forum! Thanks guys! Thanks Jerry!!! Thanks Chris and to everyone who posts on the Forum!!
 
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Reactions: Chris
Glad you figured it out. The people on this forum are a great resource.
 
Glad you figured it out and thanks for the update, I really enjoy posts like this. I'm also very happy whenever I hear that this forum is serving as a great resource to others (y)