1990xj2d

so in the past few days i decided i would change my o2 sensor seeing as i just put a new cat on my 90 renix i also changed the coolant temp sensor while i was down there. plus did my valve cover. today before i started it up i reset the computer and expected it to be a little off considering it need to adjust but after letting it warm up and driving it some the idle was still off. it sounded very chuggy but throttle response was amazing and power was there so i decided i would drive it to stockton bout 30 miles from modesto 60 mile round trip on the way i noticed that under light throttle it would start to buck and the longer i left it there the more violent it got give it more gas and it would smooth out i also noticed that its spitting out black smoke enough to leave black marks on my driveway while idling and it wasnt doing any of this before the changes. do i need to just give the computer more time to adjust? i know it take 50 key turns to learn but should i just give it more time and miles and see if it smooths out or is there a problem going on? maybe the bosh o2 sensor was bad out of the box?

tjwalker

If you did NOT have these symptoms before you replace the oxygen sensor and the coolant sensor, I'd suspect that one of these components is bad out of the box.

Bosch oxygen sensors are usually a pretty good fit for Renix. Jeep used Bosch oxygen sensors for 87-90 before switching to NTK. Where did you buy your coolant temp sensor?

cruiser54

How about this? The vacuum line from the throttle body to the MAP sensor has been split/disconnected/cracked.

FWIW, Renix computers do not reset. Other than every time you shut the Jeep off that is.

1990xj2d

Coolant temp was bought from kragen bwd brand I beleive

1990xj2d

Thanx for the heads up on the computer cruiser wasnt sure but I disconnected the battery and held the terminals together to clear it ill definetly check the map sensor maybe the line got knocked off or split while I was putting in the valve cover

akita8

X2 on the vacuum line to the MAP sensor

1990xj2d

Also thinking I met check my tps sensor adjustment and voltage it IS from autozone lol

1990xj2d

Checkd the vaccume line to the map and it was broke in two places fixed it running way smoother but idle still seems low

cruiser54

Replace it. I'll bet it's got issues in that hose somewhere else. Try spraying the line from one end to the other with carb cleaner, especially where it plugs into the TB.

1990xj2d

Replaced most of it with new soft line just left hardline right off the TB...also just out of curiousity what is the idle supposed to be at on a renix?

cruiser54

IIRC 650 -700 in D.