4.2L engine stalling

[lakenheath24]

i just inherited a 90 YJ w 4.2 and 5 speed. my problem is that it's just started stalling. it will fast idle(sometimes) but when it kicks down it quits immediatly, i have to keep the gas going at the stop light or it'll quit. i've checked the vacuum lines and i saw no holes and everything's connected. it has a new carb and what looks like a new choke controller(left side of carb)? it runs fine but definitly very rich. any ideas? also what does the solenoid on the right of the carb do? any help is much appreciated!

[kloppk]

I had an 89 YJ so I know what you are going thru.
The solenoid on the carb is the Sol-Vac. It is used to open the throttle
a little. It is controlled by the ECU computer behind your glovebox.
Here is some info on adjusting it. Sol-Vac (http://www.off-road.com/jeep/tech/258bbd/solvac.htm)

The idle problem may be a host of problems:
Usually a vacuum leak or clogged venturi tubes in the carb.
The venturi tubes get clogged and the carb drips too much gas into itself.

Here is a good index to lean what's what and how to test and adjust all the parts that make up the emissions system.
Index Of Links (http://www.off-road.com/jeep/tech/258bbd/index.htm)

[drinkyMcBooze]

you might want to check to see if both of your air fuel mixture screws are there. i had the same problem and my carb was also new. it ended up being that i lost one of the screws.

[lakenheath24]

awesome link kloppk :coool: my 5.0 got totaled a week ago so i an gonna get back into 4WD's for awhile. i am interested in seeing what the computer controls on this thing.....it's gonna be a change for sure.

[Dan90YJ]

i am interested in seeing what the computer controls on this thing.....


Not very much at all. which is one of the main reasons for the nutter bypass.

AS far as it running rich/ not at all it is a common problem for all carbed jeeps. I had mine rebuilt once, then rebuilt it once, then put a MC2100 on it, and finally after 5 years of dealing with it swapped it to FI. I have been kicking myself for not doing it sooner.

If you do it yourself and 'make' your own kit you can swap in FI for close to the cost of a new carb.

[lakenheath24]

i was told you can remove all the smog equipment except the O2 sensor....is that true. it would alleviate alot of vacuum lines.