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CAT? CPS? Other?

brandon_750

NAXJA Forum User
Location
Yuba City, CA
1990 4.0 auto.... Jeeps starts up runs fine for about 30 or so mins and when I come to a stop light it either barely idles or dies. At this point it has little to no power unless I floor it. Even then shouldn't pull like it should. It always starts back up but runs like crap. If I let it sit for 45 mins starts right back up and runs fine for another 30 or so mins. I recently changed the TPS and adjusted it to .8 it seemed to run fine but then again I only live 15 mins from work.
After reading post after post I am thinking either partially plugged CAT or CPS. What do you guys think?

list of recent work
New 02 sensor
new TPS
New fuel filter
Cleaned and replaced negative battery terminal.
Ohmed neg terminal to ground and braided ground that goes from motor to firewall.
Seafoamed it
Cleaned most connectors and IAC removed and cleaned.

 
Last edited:
i have the same problem exactly. im not sure exactly what it is but it idles really really low after the car gets warm. i already replaced the iat sensor and it still does it. so when you figure out what it is, let me know. i need it fixed too.
 
Its an XJ thing,
You have seen what I have done. Lets see if we can narrow it down. How old is your CAT? Ever replace your CPS? What type of maintenance have you done?

Brandon
 
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