I have an 88 cherokee 4.0 with a 5 speed manual. change a fuel injector not to long ago and in the process i broke one of the vaccum lines, patched it up and it ran fine for a few days. now when im driving and pulling up to a light or something and push in the clutch to down shift it will stall. not all the time however, happens at various speeding and RPM's. ive checked everything i can think of but this one has me stumped

 

My 89 with the AW4 was doing the same thing. I just recently bought another engine so I decided to swap Throttle bodies along with the TPS and IAC. I cleaned the TB and the IAC real good before I did the swap. I am not sure what fixed it but my stalling issue went away and it idles alot better. It was either the TPS, IAC or just a really dirty Throttle body. I also had a transmission issue that went away as well but since you have a manual you wouldn't of had that problem.

 

I would say your TPS might be the issue and mabey your fuel filter. When it stalls does it just die immediatly or does it spit and sputter and then die? Last time you did a tune up?

 

I would check the IAC too...
(havent thought of a better name for the site... lol)
http://emeraldgreen97.wordpress.com/...g-of-4-0l-iac/

 

Looking for another name for the site? I'm not sure if it would represent infringement or not but may I suggest "The Idiots Guide to DIY Jeep Service and Maintenance" or, to avoid offending (or exciting) the overly sensitive lawyers, just "DIY Jeep Service and Maintenance"?

 

My 89 ,5sp,4.0 did same thing and had to replace the tps . It cost me 100 bucks cause it is different than the one on automatic , bought it at bumper to bumper life time warranty don't know if u have one of those around you or not ,but AutoZone done have them anymore and other places wanted almost 200 .

 

Check for vacuum leaks?

 

EGR Valve. Plug up the vacuum line running to it with a screw and see if it stops the stalling. If it does, the EGR is the problem.