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dj69firebird69 05-11-2009 10:13 PM

1987 Jeep Wrangler Running Issues
I have a 1987 Jeep Wrangler that I have just bought and I am having some problems with it. The day i bought it, it was running pretty good but idling a little rough, it had been sitting for a few years and only started every once in a while so i brought it home and did a little bit of a tuneup. I changed the oil, spark plugs and belts and then i drove it to the parts store and it was doing fine. Then i replaced the spark plug wires, distributor cap and rotor, now when i drive down the road and hit 30 mph it sputters and dies. I checked to make sure everything was put on right and it is and then i also put a new fuel pump on. The fuel pump did not help and it always dies at 30 mph and i can not figure out what is wrong. It has a Weber Carb and it is the 4.2 straight six with an automatic transmission. The carb most likely needs rebuilt but would that change my problem and if not then what will. Any help would be very much appreciated. Thanks

jpdocdave 05-11-2009 10:31 PM

man those carbed yj's are tough. i would say double check firing order and all, but you said you have.

if the carb needs rebuilt, do that, and see what happens.

i know its pricey, but fuel injection is worth every penny and second it takes. there's throttle body kits, or 4.0 head swap, and more. but i'd consider it, cuz you will have a lifetime of fun with that carb. even if its changed to a weber.(don't they make grills):D

dooder 05-12-2009 06:44 AM

check your float needle and seat. Seat is probably crusted and not providing enough fuel flow under load and your emptying the carb of fuel before it can refill itself.

buckshot500 05-12-2009 11:22 PM


Originally Posted by dooder (Post 371116)
check your float needle and seat. Seat is probably crusted and not providing enough fuel flow under load and your emptying the carb of fuel before it can refill itself.

^This^ + new filter!

panman59 05-13-2009 12:32 PM

if it is the carb, get a holley 2bbl. i installed one on my brothers cj-7 (4.2) works wonderful. also, get the hei dist. for the 4.2. 4wd hardware has it. oh, change the fuel filter first to a single outlet instead of the dual outlet. gas will bypass and return to the tank.try that first

dj69firebird69 05-13-2009 06:53 PM

Thanks for all the help guys. I was pretty sure it was the carb in the first place but needed some other opinions. I may also try changing the filter to a single outlet. I am ordering a rebuild kit and new filter right now and i probably wont get a chance to get it up and running again until next week but I will let everyone know if thats fixes the problem or not. Thanks again

dj69firebird69 05-14-2009 08:41 PM

I Carb is clean as it can be and I am still having the same problem. It runs great at first but once you get down the road a little bit it starts wanting to die and it doesnt get any better. I have worked on many cars and I am having a hard time with this one. If anyone has any suggestions please let me know. Thanks

dooder 05-14-2009 10:55 PM

Reread your first post. was running a little rough when bought, now shuts off after a tuneup...Check if plugs are correct, cap and rotor, and also wires. Bad wires can be tough to figure out, just throw on a different set of a different type. (old ones if you still have)
just take step backwards

dj69firebird69 05-15-2009 11:37 PM

I got it fixed now. It is running like a beast. I ended up getting rid of the dual outlet fuel filter and it had some kind of aftermarket fuel pressure regulator that i took off too. Now it runs great and doesn't die out at all. Hopefully it stays like this for a little while. Thanks for the help.

dooder 05-16-2009 06:51 AM

Happy to hear you back up running good.:blunt:

buckshot500 05-17-2009 09:01 AM

Well after re-reading this, I think the regulator was prolly the culprit.
The dual outlet filter is part of the return system & works with the charcoal canister.
It's actually good to leave this system intact.
It's tied in with the rollover valve deal.

Also if the carb ever gives you any $hit again, toss it & get an MC2100.
This mod, along with the TeamRush ignition up grade, & the Nutter Bypass make for a great running 4.2L!
All of these can be googled, & anyone actually doing them should do some board searches over at

Be sure to see the MC2100 database thread.

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