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84 pioneer has a couple issues...

thechief86

NAXJA Forum User
Location
White House, TN
ok, so i just got me another xj, after several months of not having one.
for the cheap i got me a 1984 2door pioneer 4 banger 5spd 4x4

the jeep has 150k on the clock, and runs pretty good, but sat for a long time, also has some exhaust leaks, to the point of actually missing 2 of the exhuast/intake bolts, and has a big nasty hole rusted in the muffler. it still has all the original emissions junk on it, including the original catalytic converter, which i need to replace soon anyway. question is, should i replace the whole intake/exhaust gasket? or should i just put some bolts in and see how she runs?

also, she won't stay lit at idle a lot of times. i've driven all over the place but when i come to a stop light i gotta rev the motor to keep her lit, like the float may be stuck or something, keeping it from getting gas at low rpm. i'm hoping that fixing the exhaust will help all this.

on top of that, my brake lights and dash lights don't work, as neither does the fan for the heater and a/c system. (gonna check fuses tomorrow, just haven't had a moment yet)

other than a few little things, i think i did well for a jeep that i was able to drive an hour and a half home. i've already taken her out in the woods and she does well, but the cv axles scare me, so this weekend i'll swap in newer ones with Ujoints. i'll be lifting 4.5" and installing some 32's on the stock turbine wheels.:guitar:
 
Congrats on the XJ! The '84 2.5L is notorious for vacuum leaks as it has TONS of rubber hoses and valves and what-not, and the stupid feedback carb has a mind of it's own by now. I had an '84 four-banger for a few years and here is what I learned.

There is a writeup somewhere on replacing the crappy OEM carb with a better 2BBL model. You will loose all the non-functioning emissions junk and gain a few ponies. And it will run like a top. Plan on $200+ for the swap for a new carb. Junkyard carbs are really old by now and you will be money ahead to purchase new or the kit.

The 2.5L is really REALLY gonna have a hard time turning tires bigger than 235s. I had a hell of a time keeping mine spinning enough to clear mud off them. I'm talking completely floored in 4-low while playing in the back 40 grass and mud. You probably have 4.10 gears with the 5 speed tranny, but the wimpy 2.5 is gonna be a problem with taller tires.

I kept my '84 pretty much all stock and wheeled it where I thought it could go. It never got stuck! But, trying to drive at anything over 65MPH was laughable. And the awesome trails were out of my reach. I sold my 2.5 4-banger and picked up a 4.0L XJ. It was like night and day man. Real actual usable POWER!

I personally wouldn't go to crazy on the '84 XJ. Lookout for anything with the 4.0 and try to offload the '84.

As for the lights and stuff not working? Check the clutch master cylinder. I had a friend whos '84 barfed all the fluid into the fusebox from the clutch and melted everything. Check for leakage!
 
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If it's not that hard to replace the fasteners on the intake/exhaust, try it. You can check for vacuum leaks with carb cleaner afterwards. The carb on those models had a habit of coming loose between the throttle base and main body. Carb must be removed to replace the gasket. No big deal. Vacuum leaks are most likely causing your poor idle anyway.
 
thanks guys!! yeah, i actually got this xj specifically to wheel, and to DD while it's stock.
this is the first xj i've had that wasn't a 4.0, so i know what kinda power i'm missing out on, but for the $200 i have in this little piglet, i think i'm still ahead. here in tennessee it's getting a little harder than it used to be to find running xj's for under a grand, and for what i do with them, i can't justify blowing much coin on my trail pig. heck, if i get too tired of the 2.5, i already have a chevy small block drivetrain layin around. i can alway just throw that in there. i'm happy with it, i just need to spend some time trying to get it running right. i'll prolly just rebuild this carby, and remove as much vacuum stuff as i can get away with, and go ahead and swap out the manifold gasket.
 
ok, so the poor idle was from the screws holding it together at the throttle base and carb body(good call, cruiser54!) i fixed that, and she runs like a top. i was able to replace one of the bolts for the exhaust manifold, but the other one is broken off in the head, so i'll hafta pull off the power steering pump and drill it out. i got the instrument lights working, but not the blower motor or brake lights yet. it does indeed look like something bad happened with the clutch master cylinder and the fuse box at one point, which will leave me bypassing several things in there and installing inline fuses(probably only with the brake lights and blower motor, though- they're the only ones i care about.) otherwise, i'm very happy with my xj, and i've already taken her out in the woods to play, and she does great!
 
Congrats on the XJ! The '84 2.5L is notorious for vacuum leaks as it has TONS of rubber hoses and valves and what-not, and the stupid feedback carb has a mind of it's own by now. I had an '84 four-banger for a few years and here is what I learned.

There is a writeup somewhere on replacing the crappy OEM carb with a better 2BBL model. You will loose all the non-functioning emissions junk and gain a few ponies. And it will run like a top. Plan on $200+ for the swap for a new carb. Junkyard carbs are really old by now and you will be money ahead to purchase new or the kit.

The 2.5L is really REALLY gonna have a hard time turning tires bigger than 235s. I had a hell of a time keeping mine spinning enough to clear mud off them. I'm talking completely floored in 4-low while playing in the back 40 grass and mud. You probably have 4.10 gears with the 5 speed tranny, but the wimpy 2.5 is gonna be a problem with taller tires.

I kept my '84 pretty much all stock and wheeled it where I thought it could go. It never got stuck! But, trying to drive at anything over 65MPH was laughable. And the awesome trails were out of my reach. I sold my 2.5 4-banger and picked up a 4.0L XJ. It was like night and day man. Real actual usable POWER!

I personally wouldn't go to crazy on the '84 XJ. Lookout for anything with the 4.0 and try to offload the '84.

As for the lights and stuff not working? Check the clutch master cylinder. I had a friend whos '84 barfed all the fluid into the fusebox from the clutch and melted everything. Check for leakage!
He got real lucky and it has 4.56s. I asked too. The only bummer on those axles is the d35 and the cv shafts (cv disconnect shafts, no less.)

I hate carbs so I would probably rig it for a RENIX setup at the very least, but that's just me. Give me a computer with O2/MAP/MAT/CPS sensors running closed-loop any day of the week!
 
yeah, i have a buddy with a former 4banger yj that says i can have the engine management stuff, but i don't do electronic stuff, so i might not mess with all that for a while. i'll be swapping out the front shafts soon, but i really don't think i'll break even a dana 35 with 32's and a weak little motor like this one, so i'm gonna roll with it for a while. i ran a 35 on another jeep with a 4.0, 4.10 gears, ax15, and 32's, and never had an issue with the rear 35, but i did grenade the front 30. i broke the splines on my disco shafts, and some teeth on the pinion. i'm gonna either weld or aussie-lock the rear and run it till it breaks.
i'll be changing out the clutch master cylinder next week, and probably the whole fusebox if i can find a good used one. i wonder what years will work, and if i have to get one from a 4 cyl?
 
According to the info I have from my '84 parts catalog, engine doesn't matter. The fuse panel is attached to the instrument panel wiring harness though, so be prepared to splice an asston of wires or drop the dash. Things that factor into the wiring harness you need: AC vs no AC; headlight delay vs no headlight delay (who cares), year of manufacture (probably very minor differences, but not sure), fog lights vs no fog lights, diesel or gasser.
 
Pull the fuse block and take a look at it first. I am on my second 2.5 and both of them look like the fuse block is melted. Both ended up just being full of dilectric grease. I really couldn't tell on either of them until I took the box out.
 
thanks guys! i'll pull that fuse box out, and see what i can figure out! i got the brake lights working again with an inline fuse and a couple of butt connectors, so at least i have that going for me. i haven't had a whole lot of time to work on it, but i've been driving it a lot, with no issues. i got an awesome deal on a 4.5" lift kit, all but the trackbar, so i'm lurking for a good deal on one of those and a set of tires. for now, i just want to get the electrical gremlins taken care of with something more permanent. i'm gonna try to go pick up a new gauge cluster tomorrow sometime.
 
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