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Unread 02-05-2002, 03:01 PM   #1
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Join Date: Feb 2002
Location: Georgia
Posts: 1
Jeep sputtering when cold

Hello all,
My 88 Wrangler 4.2 has a problem. When engine is cold, I get really bad sputtering at about 2k rpm, and black smoke coming out of the exhaust.

When engine warms up, problem goes away, and engine runs fine.

I figured this is carb related, but could it be the O2 sensor also? The carb is brand new, but could something be holding the choke in the wrong position? I just finished giving the engine a full tune-up.


88 Wrangler 4.2 5spd
33X11.50's, 3" lift.
Many exterior mods..
FishWagon is offline   Reply With Quote Quick reply to this message
Unread 02-05-2002, 04:26 PM   #2
Bob K
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Join Date: Nov 2001
Location: New Bedford, MA
Posts: 987
Yes, sounds like the choke is running too rich during warm-up. If the coil spring is not adjustable you might be able to adjust it by bending the arm. I recommend the JuiceBox ignition system to anyone with a pre-'91 YJ or CJ. Best $130 you could ever spend on your Jeep.
'87 Wrangler YJ 4.2 I6 (sorry, sold)
JuiceBox ignition
2 1/2" ProComp Lift
31" BFG A/T's
K&N Filter
Custom Rock Guards
Turbo Muffler
Rear Track Bar in the shed
Other Tricks I won't tell to just anybody!

'99 Grand Cherokee 4.7 V8
Towing Package
ProComp MX6 shocks
Borla Exhaust
Tow Hooks
Alpine CD with Infinity+iPod connect
Just getting started!

If you're not living on the edge...
you're taking up too much space.
Bob K is offline   Reply With Quote Quick reply to this message
Unread 02-05-2002, 10:49 PM   #3
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Join Date: Dec 2001
Location: New York
Posts: 27
I have the same problem with MY 89 YJ. I was thinking about the juicebox. Do you happen to have a picture of it? Are there different models that i should be aware of?? Any advice would be great.
Johnny'sJeepen is offline   Reply With Quote Quick reply to this message

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