The most frequent problem with the 4.2 6I is the old Carter carb and the pulse air system. Depending on the type of driving you do you may want (or have) to do something with the carb. You will need to check with your State MVD people as to what they will allow you to do.Hey all! Just bought an 89 Sahara, 143000 miles, well maintained, pretty much stock, 4.2 carbed engine. Anything in particular I should look for in the way of problem areas?
(cool site, BTW)
The factory original system required the computer to keep trying to adjust the air sent to the carburetor to burn more of the exhaust by alternating between drawing air from the exhaust manifold and the catalytic converter. One tube connects to the manifold on the drivers side straight down from the firewall and the other comes off a nipple on the top of the cat. Depending on how you drive, they frequently trap air and it condenses in the air tubes, only to be sucked up into your air cleaner (making a mess of your filter) and further screwing up your available combustion air. The MC2100 has a circular filter exposed to the engine compartment air with no intake other than the surrounding air. With that you can tune it how you want it to run, not what the factory says it should do.Thanx for the replies. My state(OR) has decided to match California in the emissions department in a couple of years, so I'm not sure what I'd be able to do with the carb.
I was thinking of installing a cat-back exhaust(not sure what size), and maybe getting a K&N air filter for starters.
The pulse air system, is that the 2 tubes running to the air filter canister?
Don't know your age, but as you get older you'll discover many more things the gov't has screwed up.Thanx for the info. Leave it to the government to take something as simple as a straight 6 and mess it up with engineering.
GJ, who makes the MC2100?
as tenacious d said in the pick of destiny (love that movie...Thanx again. And don't worry, I'm old enough to know about government and how they "improve" things.
BTW, doesn't the YJ have a 15 gallon gas tank? I just put 16.91 gallons in mine!
The stock tank was a 15 on your year, but the 20 was available as an option. Obviously you have the 20 because there is no way to get almost two gallons of gas in the filler tube.Thanx again. And don't worry, I'm old enough to know about government and how they "improve" things.
BTW, doesn't the YJ have a 15 gallon gas tank? I just put 16.91 gallons in mine!