I forgot to add my RPMs are about 600-800 on idle once it warms up. My idle is constant and does not fluctuate.
I also had my engine rebuilt about 2 years ago and installed a new O2 sensor at that time, I have installed an Airaid CAD, 4.0 throttle body, the Ford style 4 port injectors, and a DUI distributor, coil, and plug wires.
It could be the O2 sensor itself or it could be a leak near the sensor causing a lean reading. Could be the CC is on the way out. Your injectors could be leaking. So many things, but your numbers are close to passing.
My numbers were similar. Replaced O2 sensor, map sensor, plugs, wires, CC, muffler, and it passed with flying colors. Running rich will fry the cc pretty quickly (a few months), so it is an issue you might want to address soon.
'94 YJ 2.5L Red
"If you don't smell like exhaust, then you're doing something wrong"
on a 91, I'd first replace the o2 sensor. Even just 2 years can end up with an 02 sensor thats wonky but not throwing a code -yet.
The exhaust leak Que mentioned would be my second area to look for. You should be able to hear it, but if you can't, usually a thorough visual inspection will find it. My SMOG guy almost always can tell me why I didn't pass - i.e. what needs replacing.
SOME WORDS OF WARNING: Before you replace the Catalytic Converter in CA, have the shop show you the CAT they are recommending on the LIST OF APPROVED AFTER MARKET CATS for your ENGINE GROUP or TEST FAMILY. If they put on one that isn't on that list, you will have to pay to replace it again. The SMOG stations are now required to verify that the CAT you have is one from the CARB List of approved CATs for your vehicle. Ask me how I know....
I sprayed all around the intake and vacuum hoses and there was no change in the rpms.
I did change the plugs also. They have probably less than 15000 miles on them since they were installed.
I will check my exhaust system for cracks but as of right now I dont hear any air leaks from the exhaust system. Im pretty sure its going to be a good reason for a new exhaust system. I just dont want to lay out the money and not find out what caused it to go bad and fry the cat. I did not know about the different cats and the carb certs on them. Thanks for the info LUUCA.
The engine does not burn any oil and im currently runing 10w30.
Im also waiting to find a fuel pressure guage so I can test the pressure at the fuel rail.
[QUOTE=mike134;25124738]You said you replaced the distributor and plug wires, I assume you also replaced your spark plugs? Did you use the copper core or platinum? The jeep likes a hot copper plug.
If you're running rich, they may be fouled already. I'd pull them, clean them, check the gap, maybe even replace them.QUOTE]
Why do the jeeps like the copper plugs over the platinum or other fancy ones? Im currently running the E3's and haven't had any issues with them yet. I also have the DUI ingnition system which throws a hotter spark than the factory system.