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Unread 12-09-2013, 10:33 AM   #1
Kingston
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1987 YJ Wrangler 
 
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4.0 or 4.2???

Ok I just recently purchased a 1987 YJ Wrangler Sport, i bought it for 2400$ which to me wasnt that bad and i am going to be using it as my daily. The issue im having is that all the emission controls have been striped of the motor, it dont bother me really but since i can look and clearly see that the motor has had someone in it....idk for sure if its the 4.2 that came with the jeep or the 4.0

Im new to the Jeeps..Sorta, my dad had a couple Willis Jeeps a 12v and a 24v mil specs and ive done Mud Pit Jeep ( in Ms and La )....

also ontop of just getting into this stuff, i just moved last week to MD and have no idea were good places are to get work done here since all my tools and welding machines are back in Mississippi lol

jeep-motor.jpg  
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Unread 12-09-2013, 10:38 AM   #2
Kingston
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like previous stated, the motor has been striped down to the Bare necessities lol which is fine with me cuz i dont plane on doing rock crawling with the truck so i wont be getting into extreme situation to need a FIJ motor, but the tuning is off badly on the carb, it runs fine down the road, im use to old school trucks since i perfer these old type of motor over the new computer BS. but im mostly use to stuff like race motors for mud drags, NEW motors really lol. but this one lags to start with heavy feathering of gas pedal then sometimes goin down the rd u have to continue to feather the gas when slowing down or stoping or slowing down to turn or it dies altogether....but when its running it runs great....
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Unread 12-09-2013, 10:43 AM   #3
LilyBayXJ
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That looks like the 4.2L to me.
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Unread 12-09-2013, 10:43 AM   #4
Kingston
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also as you can tell, the original air filter cover has been removed and the small "hot rod" style put on, which means the PCV has been removed and that stupid air filter placed in the valve cover....again to me with race cars this would be fine...but it seems like trash from 4x4 use would get in....plus as you can see it allows oil to get out...so is there a way to stop the oil from leaking out from there....i rather keep all the Emission BS off the jeep
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Unread 12-09-2013, 10:50 AM   #5
tom_sprecher
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Since there's a fuel pump bolted to the side of the block I'd say it's a 4.2. Even if someone would bother to put a carb on a 4.0, it would not have a mechanical fuel pump. That's unpossible.
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Unread 12-09-2013, 10:52 AM   #6
Kingston
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ok, 4.2 it is...thank yall, what about the problems im having...any ideas??
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Unread 12-09-2013, 10:53 AM   #7
mark8201
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Just looking at the photo, it looks like the carb may have been replaced with a weber or MC2100. This would be why most of the emission and and stock air filter have been removed. I would figure out exactly what you have and try setting the timing and adjusting the carb.
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Unread 12-09-2013, 11:02 AM   #8
Kingston
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yes the carb was replaced, when i bought the jeep i got alot of the original stuff back...carb, air filter houseing and everything that was removed really plus the soft top and extras for it...im in Cockeysville, and i rather put it a shop in get the carb tuned up, does anyone know of a place for this near me?
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Unread 12-09-2013, 11:05 AM   #9
roadyrob
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PCV is connected to the carb, the filter is for fresh air into the motor. have run mine for years like that, no problems. its a 4.2, the 4.0 didn't have a mechanical fuel pump.
the carb doesn't look like the original carter BBD, take a pic with the air cleaner off.
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Unread 12-09-2013, 11:12 AM   #10
roadyrob
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your valve cover is an 8 bolt not a 15 bolt like on the newer 4.2's. have heard that some 87's came that way, first time I've actually seen one.
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Unread 12-09-2013, 11:40 AM   #11
Kingston
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Quote:
Originally Posted by roadyrob View Post
PCV is connected to the carb, the filter is for fresh air into the motor. have run mine for years like that, no problems.
ive run them on new project trucks n cars before also....but never on any of my Mudtrucks...but my biggest concern is the oil that is being lost threw this, u can see it comes out the filter and runs down the back of the Valve Cover
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Unread 12-09-2013, 12:02 PM   #12
roadyrob
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be sure your PCV is working correctly and the hose isn't plugged. I'm not sure about how its hooked to the carb, be sure theres vacuum there. your valve cover is an aftermarket made by omix ada (I mistakenly bought one for my jeep) there should be a baffle under both inlets to help keep the oil out.
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Unread 12-09-2013, 12:11 PM   #13
Kingston
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i do have one line pluged idk what it goes to... like i said the previous owner to all the emissions controls off, and installed a new Carb. I have only 1 pic of the motor at this time since the jeep is at my GF's parents ( apart complex tows non tag vehicles)

the hose circled in red is the pluged line. and also i thought the PCV valve pluged into the Valve Cover and a line connected it to a vent in the Air Intake Cover.....i remember on a older chevy having to replace this since the ball was stuck in the valve....but like i said im new to jeeps. THANK Yall for all this help
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Unread 12-09-2013, 12:13 PM   #14
Kingston
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here the pic
jeep-motor2.jpg  
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Unread 12-09-2013, 12:57 PM   #15
roadyrob
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its hard to tell in your pic but it looks like the PCV line is hooked to the top of the carb, it should be hooked to vacuum. on my old weber and the holley I run now the PVC hooks to a nipple in the adapter under the carb.
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