Rough Running .. no pwer intermittant

[ksmith]

I'm trying to figure this one out. Usually when my 89 xj 4.0 w/ aw4 is cold
I have some very rough running.
Here are the symptoms: Engine runs very rough, Tach bounces from zero to proper rpm. Give more gas, no result, let foot off accelerator runs fine, add gas, more studdering. Then it will just "cure itself" and run fine. This could take anywhere from 1 minute to 10 minutes to "cure".

What I've done- Changed plugs, dist cap, changed plug wires for jacobs and it was fine for a few months in the summer, thought I had it solved.,cold weather came more problems... changed tps, oxygen sensor on top of manifold, changed map sensor, cleaned all grounds, changed egr

what am I missing?
I'm actually considering changing to propane if this persists much longer

BTW I'm new here

thanks in advance
k

89 xj soon to have d44
88 yj frame up rebuild
89 mj retired for the time being

 

[langer1]

I'm trying to figure this one out. Usually when my 89 xj 4.0 w/ aw4 is cold
I have some very rough running.
Here are the symptoms: Engine runs very rough, Tach bounces from zero to proper rpm. Give more gas, no result, let foot off accelerator runs fine, add gas, more studdering. Then it will just "cure itself" and run fine. This could take anywhere from 1 minute to 10 minutes to "cure".

What I've done- Changed plugs, dist cap, changed plug wires for jacobs and it was fine for a few months in the summer, thought I had it solved.,cold weather came more problems... changed tps, oxygen sensor on top of manifold, changed map sensor, cleaned all grounds, changed egr

what am I missing?
I'm actually considering changing to propane if this persists much longer

BTW I'm new here

thanks in advance
k

89 xj soon to have d44
88 yj frame up rebuild
89 mj retired for the time being

Dirty gummed up IAC, dirty TBS.

 

[AJPulley]

Do a search, there have been quite a few threads in the past two months for rough runnign Renix 4.0s (87-90). Start diagnosing all your sensors- temp, MAP, etc. If you want a .pdf of the Renix manual, PM me with an email address. After you've done that, let us know.