89’ Pioneer MJ Barn Find

[oleskool]

Here is the 89’ Pioneer I picked up for $500 in July. I’ve known about this truck for years but it has taken this long for the family to agree to sell it. I bought it from the original owners son. This truck has been parked for several years (inside a barn). It was parked because it was running rough lol. After it got parked a family of rats decided to move in judging by the nest I found behind the radio.   Here it is after I pulled it out of the barn with my dad and the day it was brought home. The truck would start up on starter fluid but that’s it. 
 

this is a late 89’ truck 4wd 5 speed AX15 4.0. 
 

clutch was stuck, didn’t run off gas tank and the brake had rusted up so it didn’t roll well lol. 

[oleskool]

Since that day I dropped the tank to find what I expected, gas tank was rusted beyond repair and the fuel sending unit was in the same shape. I purchased a new tank and MTS sending unit and cleaned the fuel lines while I was at it. Slapped the tank and a new fuel filter in and boom she cranked up. Unfortunately that led to a complete fuel rail geyser of gas. Leaks from all the connections and fuel pressure regulator. But hey at least it cranked. 
 

with a new fuel system in place and upgraded 4 hole injectors it finally cranked and idled for the first time in years. After that it was time to upgrade all the connections and power / ground wires. I grabbed cables from Jeepcables and went to work. Upgraded and cleaned everything all the way to the fuse box (nothing really worked like the blower motor, dash lights, etc). Found the fuse box is corroded like many others but I salvaged it for now. I have a good used one sitting in the shop waiting. 

[oleskool]

Next up was the cooling system. The coolant looked like rust water so I drained and flushed the block. Added Thermocure to the block with pure water, burped the system and let it idle for a hour or so everyday for a week to circulate / treat the block. Meanwhile I ordered a new thermostat, water pump, fan clutch, idle pulley, serpentine belt, radiator hoses etc. after a week the system was flushed throughly and a new cooling system besides the sealed radiator was installed. I held off installing a new radiator because it was holding coolant fine. I plan to convert to an open system soon but for now I’ll focus money to other areas. Everything buttoned up and it seems to be cooling properly. 

[oleskool]

At this point the truck runs but doesn’t move because the clutch is stuck. My dad cranks it up and let’s it run every couple days for a few minutes got impatient and started working the clutch pedal (their may have been a rubber mallet involved) and magically I get this from my mom while I was at work. So at least it runs and drives haha. 

[oleskool]

After this we now had to turn to the brakes. The goal was to drop the booster and MC. Then go around and replace the brake pads / shoes and put in new soft brake lines. So that went about as expected. Brake Booster are a pain to pull for something with just 4 bolts lol. Since I had to pull the driver seat to lay in the cab I went ahead and started the interior strip project at the same time. With the new MC and BB installed I went to knock out the rear brakes first. The rear wheel cylinders were leaking as expected which lead to a wild ride re flaring brake lines. I’m accustomed to old jeeps but this thing has every brake fitting locked in place like no other. I scrapped the hard lines on the rear axle and ran -3AN SS flex lines like I do on my offroad rigs. So after a couple days of reworking hard lines and bleeding air we finally have solid brakes again. The front brakes are next but my back needs a rest after this. 

[oleskool]

Now with the interior stripped I needed to see what kind of rust we are dealing with. The underside of the body is immaculate. This truck was well cared for but like most jeeps it does leak. I pulled the carpet and found some superficial rust in the pan. Then I got the insulation on the fire wall out of the way. Sadly I found one small 1” diameter hole where the foam holds water. Not a big deal as long as it’s treated properly. I use POR15 on my CJs and with good success as long as you are very careful in prep. I wore wheeled the floors, vacuumed up the mess, degreased the floor and added their metal prep to neutralize the remaining cancer. After that I went over it with their rust coat and finally a black top coat. Since I’m stripping the cab I might as well add sound proof and insulation. I’ve gotten the sound proofing in and hopefully this weekend it will buttoned up. I washed the carpet while I was at it so it smells better lol.

[tugboat95]

SCORE! And in Carolina as well.

89 Comanche
Eliminator
2wd
4.0L
5 speed PukeGoat
Factory Original

[War_Pony89]

Man that is a killer find, floors cleaned up nice. I'm finishing sound proofing my cab. Had a two inch hole patched. Buying carpet today. The dynomat looks good.

[howeitsdone]

That's a fairly clean truck right there. Fogs look nice.

[oleskool]

1 hour ago, War_Pony89 said:

Man that is a killer find, floors cleaned up nice. I'm finishing sound proofing my cab. Had a two inch hole patched. Buying carpet today. The dynomat looks good.

It’s a very clean truck. I still have a layer of insulation to put over the mat and the roof to knock out. Hopefully it makes difference. 

[oleskool]

34 minutes ago, PocketsEmptied said:

That's a fairly clean truck right there. Fogs look nice.

I'm excited to get it back on the road full time. The paint would be pristine but they let one of their grandsons drive it for a bit before it was parked. He sprayed undercoating on the dark blue paint trying to black it out for some reason. It’s slowly coming off with mineral spirits. 

[89 MJ]

Good looking truck. Sounds like you must be another young guy too. 

[JMO413]

Good looking truck!!

[oleskool]

1 hour ago, 89 MJ said:

Good looking truck. Sounds like you must be another young guy too. 

Thank you. Not sure about young. I guess it’s all relative haha. I’m 38 and this is the first MJ I’ve messed with. I love old jeeps and have several CJs including the first one I bought when I was 16 many moons ago. The next project is a 46 Willys I bought from a local guy that actually purchased it from my dad when he was 20. One thing at a time though lol. Some of the other toys. We can’t just have one right!?!?!

[oleskool]

I guess I should add the plan for this truck. The car enthusiast in me really wants to lift it and throw 35’s on it but I already have two heavily modified jeeps so I think for this guy it will be more practical and nostalgic to keep it as close to bone stock as I can. I wanted to do an updated interior swap but the blue interior kinda takes me back to when I was a kid in this era. I learned to drive in a 83’ Datsun King Cab Truck with blue interior. So I think it will stay bone stock with some minor performance upgrades that add reliability and etc. I will keep the 235/75/15 tire size though. I really love the look at stock ride height. Oh and I will put the flares back on when I’m finished cleaning her up. 

[oleskool]

Finally got a little time yesterday to get the insulation in. Waiting for the core shifter to arrive and I’ll get the carpet and interior back in. 

[Rob S]

Nice, currently doing an 89 Pioneer myself.  I need to update my project post here soon.  Just finishing up the paint and reassembly.  Your truck looks awesome, keep up the great work and progress photos!!!!

[Pete M]

that insulation is going to help for sure!   

[oleskool]

Final piece of the interior just showed up. Core short throw shifter with hurst gear shift. Someone cut my ax15 handle down low and by the time I rebuilt mine and bought a new lever arm I figured I might as well splurge. Also picked up a set of rugged ridge floor liners for a Cherokee. Figured I would see if I can make them fit right. If not I can send them back I guess lol. I run husky or weather tech floor liners in all my jeeps and would really like to have a set in this one too. I guess this weekend I get the interior in! 

[Lthompson741]

Looks good.   Cleaned up really well.   The rugged ridge floor mats are “decent”. I’ve got a set in my mj.    Mine were curled from being in the box for who knows how long.   
 

I wish mine was a 5 speed but there aren’t to many left in the rust belt around me.

[War_Pony89]

Y'all left me inspired, ordered my carpet, inner fenders and rugged ridge floor mats today.  Found my leak up front, antenna plug is pushed out, think that is my main leak cause, so green light finishing the interior!  Now just need a nice warm sunny day to lay the carpet,which are in short supply as of late.

[Pete M]

22 hours ago, War_Pony89 said:

Y'all left me inspired, ordered my carpet, inner fenders and rugged ridge floor mats today.  Found my leak up front, antenna plug is pushed out, think that is my main leak cause, so green light finishing the interior!  Now just need a nice warm sunny day to lay the carpet,which are in short supply as of late.

 

 

there are dozens of ways for water to get in.  do make sure you test after plugging the most obvious hole.  

[oleskool]

20 hours ago, Pete M said:

 

 

there are dozens of ways for water to get in.  do make sure you test after plugging the most obvious hole.  

I am in the process of doing the same thing haha.  Mine appears to be firewall area.  I was thinking windshield or air vent but I have poured gallons of water in those areas with no water coming in.  My bad spot is the drivers side.  My next guess is that the hood to cowl seal is old and dry allowing water to pour in around the back of the hood and down the fire wall but I have yet to prove that theory.  The passenger side has a very small leak somewhere, may be the antenna seal / grommet but I have not had time to check this one out.  I am hoping to have most of the interior etc back in Saturday so it can be driven again.  After that I will be bringing back to my garage (its currently sitting in my dad's shop) so I can start the trouble shooting process and hopefully put some miles on her 

[oleskool]

Update, picked up a mostly complete navy blue interior from an awesome member here. Really I just needed the dash as mine is cracked. Need to do some cleaning to it. SEM soap, vinyl spray prep and some SEM shadow blue should work nicely. I’ll probably clean and spray every panel in the jeep so they all match. This will be a winter project though. My goal for now is to get it back together so I can bring it back to my garage. Then I can work on it at night after work etc. 

[oleskool]

Not a bad day working on the MJ today. Got the core short throw shifter installed, put the pressure washed carpet back in, cleaned up the seats, mounted a new rear view mirror, threw in the rugged ridge mats and took her back out for a good 30 minute drive. Happy to have the interior all back in and the smell of mold and mildew out. Shifter takes some getting used to but overall I’m happy with. The liners fit good but take a little getting used to as well. The sound proofing and insulation are night and day difference. The truck is super quiet now. Pretty impressive what $90 in materials do.