I just bought a 87 jeep and it won't pass Colorado emissions. We have bought a new carb and did all vacuum lines, cleaned mother of carbon, used e-85, has 33 inch tires I have been told to go buy smaller tires and it should pass emissions I don't understand why that would help but we also put a new cat on a California rated one oil change charcoal canister still is good it suffers from high co and high hc any help would be appreciated thanks
I'm in colorado too. I've been working on a 1990 yj for my sons 1st jeep and it was having a difficult time passing emissions. I finally just bought a used howell tbi kit ($600) and it passed with flying colors. Probably not what you want to hear but for me it was totally worth it. Increased performance and piece of mind that it will start each and every time without any worries.
You can't register as historic here for classic plates it has to be 1975 or older now. You don't think you could pass with a carb here in Colorado. I'm having the o2 sensor checked and the nutter bypass done. As of today I have also did new spark plugs and points plus put in Moab and we cleaned the motor again with 109 engine cleaner we have e85 in it and we're doing the high altitude adjuster and I removed the full time locker in the rear end. I'm really running out of ideas here what else can it be that causes a engine to run to rich or stopping the fuel from burning all the way????
1.Why the hell are you running E85?
2. How many miles are on the jeep? My guess over 160k
3. What kind of oil are you running?
4 You don't have points in your distributor.
5. Your cat is most likely junk. You have a huge vacuum leak between you intake and exhaust gaskets
6. You probably have an oil soaked air filter as well.
7. Try 10w40 or even 20w50 oil to compensate for you loss of compression.
8. Replace your cat and O2 sensor.
9. If that doesn't work swap it to a 4.0 and quit screwing around and wasting money
The pictures I show does not show that with the nutter just working with the purple and orange wires then setting distributor to 8 btd and I'm just telling you what mechanic and I have done it has a new cat we put in a heavy duty cat
E85 may be doing more harm than good. These motors weren't designed to run on it. Changing the tires and removing the locker wont effect your emissions any. Start with the basics:
-check for any vacuum leaks using carb cleaner, WD40, starter fluid, et cetera
-research and connect the high altitude jumper wire
-if your engine is high mileage then run a thicker oil (prior to rebuilding my 4.2 i ran Valvoline VR1 20W-50 which the motor LOVED)
-what did you gap your plugs at?
-what work has been done to the motor? is it all stock? if your not sure then post some pictures for us to at least get a better idea of what we're dealing with.