1996 Jimmy rough idle - still trying

[wildcatsua]

Got off early yesterday so stopped at Auto Zone and picked up the regulator ($56). Pulled the plenum - just as I remembered it - sooty in front and clean in back (near the firewall) where the regulator is attached to the fuel body. Replaced the regulator without pulling the poppets out of their holes. Regulator is secured to the fuel body with an easily removable metal spring type clamp.

Amazingly, my problems seem to have been have been solved. SES light out. Starts right up. Idles fairly smooth, much better than before - it does have 95k miles so I don't expect perfection.

I've been chasing this for 4 months so I don't want to celebrate early but the difference is amazing. This was a big learning experience for me. Hope it helps others who read.

Not to be critical but I'm surprised none of the experts suggested this possibility. I'm so lucky I spent the $50 to take to the shop for analysis. Or actually, so lucky I ran into somebody who has seen this problem so many times before - that's why I'm surprised none of the experts suggested it. The guy at the garage said it was commonplace and described it in exact detail.

I would like to post the picture of the plenum for reference. It seems to be a perfect indicator of the fuel pressure regulator problem. Please tell me how.

Will update if anything changes.

Thanks to all who helped!

[1993 Jimmy]

I could not figure out how to post pic on here.
I guess I am back to square one with my 93 Jimmy it was running fine then it got hard to start again. I've changed the CPI unit, cleaned the upper and lower intake, and cleaned the EGR valve and all the other sensors in the intake. Not it is down to either the CAT or a stuck valve. any suggestion which way to go?