mcpherson's YJ Build Thread

[mcpherson]

Figured this would be just as good as anywhere to document my Jeep build thread.

For as long as I could remember I have always wanted to own a Jeep (dont worry, the explorer still has some plans ahead of it and will not be going anywhere.) So after some searching I located a deal on a Jeep and purchased it. I had all best intention of leaving the orginal engine with carberator and transmission, well on the hour long drive home this thought change very quickly and 2 days later I purchased an XJ donor vehicle for the complete engine, wireharness and computer. As further plans went, I ran some compression test on the XJ jeep and it wasnt looking so good; so the next best thing was to test the YJ engine and voila, it came back with excellent results. It was concluded that I was going to purchase a rebuilt cylinder head (4.0 Cast #7120) and with some modifications mount it on the pre-existing 4.2 YJ block.

Stock Specs:

• Engine - 4.2L I6, 2-B Carb (160,000+ miles)

• Transmission - TF999

• Trasfer Case - NP231

• Front Axle - Dana 30

• Rear Axle - Dana 35

• Axel Gear Ratio - 3.54:1

• Suspension - Stock

• Tires - 31'

Engine Swap
- Purchased a donor 95' XJ 4.0 Sport

- Parts List:

• Remanufactured Head Cast#7120 (RockAuto.com)

• Motor Oil (Local Auto Store)

• Spark Plugs (Local Auto Store)

• Spark Plugs Wires (Local Auto Store)

• Distributor Cap (Local Auto Store)

• Rotary Button (Local Auto Store)

• Water Pump - FlowKooler (Quadratec.com)

• Thermostat (Local Auto Store)

• Oil Filter (Local Auto Store)

• Serpentine Belt (Local Auto Store)

• Upper Gasket Set

• Crankshaft Seals (Local Auto Store)

• Electric Fan

• Exhaust Studs

• Electric fan Control Unit (DCControl.com)

• Fuel Pump (RockAuto.com)

Transmission Swap
- AW-4 Transmission from an 88' XJ

- Parts List:

• Novak Shifter Assembly for New Process - 231 Transfer Case

• Front & Rear Main Seals

• Filter & Gasket

• Transmission Fluid - 8 Quarts

Misc & Replacement Parts (Other then engine/transmission related)

• Soft Top & hardware - Bestop 54599-15 Supertop Black Denim Soft Top with Tinted Windows (Amazon)

• Cleaner - Bestop Protectant & Vinyl Window Cleaner (JC Whitney)

• Front Floor Mats - PLASTICOLOR (JC Whitney)

• Rear Cargo Mat - PLASTICOLOR (JC Whitney)

• Black Lower Door Hinge Brackets - Smittybilt 7607 (Amazon)

• Black Windshield Hinge Brackets - Smittybilt 7603 (Amazon)

• Black Complete Hood Kit - Smittybilt 7699 (Amazon)

• Extreme Black Sport Handle - Smittybilt 769310 (Amazon)

• FAIRCHILD INDUSTRIES 13 Piece Weatherstrip Kit (JC Whitney)

• XJ Hayes Manual (Local Auto Store)

• YJ Hayes Manual (Local Auto Store)

Soon to be here after mods:

• BDS Suspension - 3-1/2" Lift Kit w/Shocks

• M.O.R.E. Front & Rear Boomerang Shackle (5/8" lift)

Related Information:

Engine Specific

• Jeep Strokers

• 4.0 head and EFI on a 4.2 block

• Post#8 from MellowYellow

• 4.0 and FI swap onto a 4.2

• 4.0 Head, MPFI, and Serpentine on my 82 258

Transmission Specific

• Renix AW-4 Transmission Swap into a YJ

• AW4 swap into YJ w/4.2

• AW4 in a YJ

• Jeep YJ Manual to Auto Tranny Swap

• Renix to HO Throttle Body

• RENIX to H.O.

• Pages 1-3 - TPS (Throttle Position Sensor)

 

[mcpherson]

Wire harness from the donor XJ:

Yes, it really is that bad:

The rear of the wrangler full of the XJ 4.0 engine parts

 

[mcpherson]

Well, being that it was Easter weekend I only achieved a few hours to work on this. Some parts came in last weekend, one being the fuel pump so below is a picture of it. The other photos are of just of progress and misc.

E2000 - Fuel Pump:

Progress Pictures:

4.0 sidepiece of block and bolt holes

 

[BradR]

So you're keeping and fixing both Jeeps and the Explorer?
I'm so lost. lol.

I love Jeeps and would own and drive one all the time, but I would be WAY to cold in the winter and would then hate it.

 

[mcpherson]

So you're keeping and fixing both Jeeps and the Explorer?
I'm so lost. lol.

I love Jeeps and would own and drive one all the time, but I would be WAY to cold in the winter and would then hate it.

I went back and forth on the thought of to keep or not to keep the Explorer, but I enjoy driving it so much. Plus I have some thoughts of what I would like to do with it down the road. As for you being lost I think the term "It's a jeep thing" covers it, but hey not to worry I am lost also with this also, I suppose keeping the Explorer is keeping me lost. I don't like the cold myself, so it does have the hardtop for the winters and worse case the Explorer is there unless its receiving the a new axle or 2... and the jeep may need that rear 8.8 axle, opps did I just write that.

 

[BradR]

Haha, you're my kind of guy.
My buddy has a Jeep, I kind of understand the Jeep thing, he just doesn't do it right. lol.

I'm having a similar problem trying to decide what to keep or sell with my Mountaineer or Explorer, as I can't afford 2, and don't have a need for 2 at the moment... while I can get my hands on a supercharged302 for the Mounty, I don't really want to do it, and I'm tired of the Explorer, I've owned that a year and a half and I have nothing left to do with, and I want a street truck, my mind is just full of ####. lol. There's a lot more going on than what I just said. But I don't wanna clog up your thread here.. lol...

This is his 87 YJ? I think, IDK! 4cyl 5 speed that goes tick tick tick.
And my Explorer in the back ground yay!

 

[mcpherson]

Haha, you're my kind of guy.
My buddy has a Jeep, I kind of understand the Jeep thing, he just doesn't do it right. lol.

I'm having a similar problem trying to decide what to keep or sell with my Mountaineer or Explorer, as I can't afford 2, and don't have a need for 2 at the moment... while I can get my hands on a supercharged302 for the Mounty, I don't really want to do it, and I'm tired of the Explorer, I've owned that a year and a half and I have nothing left to do with, and I want a street truck, my mind is just full of ####. lol. There's a lot more going on than what I just said. But I don't wanna clog up your thread here.. lol...

This is his 87 YJ? I think, IDK! 4cyl 5 speed that goes tick tick tick.
And my Explorer in the back ground yay!

I hear ya bud, decisions can be hard to make. Just flip a coin and stick with it.

 

[mcpherson]

As you can tell, new & old head:

Backside of the new heads water slots:

Somewhat not organized 4.0 parts:

Discovered this while detaping the the YJ's wiring harness. This will be replaced and the rest of the vehicle will be under close attention.

 

[mcpherson]

More goodies arrived yesterday.

Obviously this is a FlowKooler Water Pump, Model 1747:

Fuel Pump Block-Off Plate:

Dial Indicator (because each setup can be different in regards to Push-Rods, I purchased this to verify what will and will not work):

Novak Shifter Assembly for New Process - 231 Transfer Case:

 

[mcpherson]

Also got around to removing the head form the YJ, and just as suspected the cylinders look pretty good:

Was also able to have most of the wiring pulled to the side, 3 reasons for this is:

1. remove old engine wiring
2. clean oil off wires
3. inspect all wires for cuts & bare wires