The previous owner of the DJ jeep mentioned that water kept getting into the fuel tank. This will be fun to get working. A flat blade screwdriver and a hammer tapping on the fuel sender locking ring and we can get a look inside.

This fuel sender looks like it was on the Titanic.

That is a lot of rust inside the tank :(

The tank dropped out with the removable of 6 bolts and tons of dirt and rust.

I took the fuel tank straps off and pulled the tank off the skid… The skid has traces of old gas and varnish on it… Not a good sign for the integrity of the tank.

Filling the tank with water confirms my fears. The tank leaks.

I could try repairing the tank by removing all the rust and applying a liner but I think I am going to change to a CJ-5 Jeep Tank. Some searching online shows this won’t be a direct swap but it I should be able to make it work.

I ordered the following:

• MTS Company 0051 Fuel Tank
  • Fits the 1978-1986 CJ Jeeps
  • This is a plastic tank that fits CJ-5 and CJ-7 Jeeps
• Omix-Ada 17724.09 Fuel Pickup and Sender
  • OE Reference: 5357373K
• Crown Automotive J5357023 Fuel Tank Skid
  • My original skid does not fit the CJ-5/7 plastic tanks
• Spectra Premium ST60 Fuel Tank Straps

Tank assembled with the new sending unit, tank straps, and skid. I added some 1/16″ thick rubber between where the metal contacted the plastic tank.

The skid needed some trimming and holes drilled to make it fit the DJ frame and cross members. The tank and straps did not need to be modified.

One of the problems with this tank is that it moves the sending unit. Not a problem for the wiring and fuel hoses but the access panel for the sender doesn’t line up anymore. Not a problem for a angle grinder though.

I cut the access panel large enough to access the new location of the sending unit and then riveted in some aluminum strips so I could screw down an aluminum plate to cover the hole.

Still need to see why the fuel gauge doesn’t work but the sender works and the tank hooks up to the stock filler hoses for this 1979 DJ.

Here is how the fuel lines are routed up to the engine. The fuel comes from the tank in a 5/16″ line into a clear fuel filter. This goes into the intake side of the mechanical fuel pump. From the fuel pump it goes into another metal fuel filter. This fuel filter has a bypass line that has a restrictor inside. Bypass line is 1/4″ diameter and the smaller of the two barbs on the fuel filter. This goes back to the fuel tank. The other outlet of the fuel filter is 5/16″ and goes to the carburetor. The bypass line keeps fuel pressure down when the bowl float valve closes and allows the fuel pump to keep fuel moving in the lines to prevent vapor locking… in theory at least :)

Now lets see if the new fuel sender works with the old crusty fuel gauge.

With some fuel in the tank we are getting 36 ohms. So we might be good!

The gauge didn’t work but taking apart and cleaning the gauge cluster got it to work correctly.

Contact cleaner and some adjustment and we have a working fuel gauge and tank!

Almost all the electrical on the dash didn’t work besides the ignition switch. Over time stuff started to start working which lead me to believe that most of problems was due to connection and corrosion problems.

The Jeep came with a headlight switch so that was the first thing I replaced. This got the gauge lights and other interior lights working but the headlights didn’t work still. The wire from the headlight switch that goes to the headlights bulbs has 12V so the new headlight switch is working correctly.

Looking at the wiring diagram for the DJ Jeep, the power from the headlight switch goes to the hi/low beam switch on the floor. Poking at the hi/low beam switch with a multimeter showed that 12V was getting to the switch but not coming out. Time to see what is up.

Here is the switch, doing a continuity test shows that no current is passing through. Opening up the switch shows it looks ok.

I cleaned the internal contacts with some contact cleaner anyways and reassembled. Switch still did not work. What I can figure, is that the pressed rivets that hold the contacts on have corrosion. I soldered the rivets together like this.

Which fixed the switch. This is the same switch used on the CJ jeeps so if this fails again I can just get a replacement.

Headlights work! The gauges on the dash work but there is clearly a problem with the grounding or power to the gauges as they are not correctly reading. I will try replacing the ground strap from the engine to frame and add one from the frame to the dash like modern Jeeps have.

The DJ Jeep came with a set of new in box shocks. The ones on the Jeep where out of gas. I dunno how long these old new in box shocks will last but they are at least working for now.

What is weird about the suspension is that the front shackles have been replaced at one point with lifting shackles.

The previous owner mentioned that this Jeep was once used as a boat ramp launching vehicle and suspected that these longer shackles where installed to prevent the suspension from bottoming out.

I dunno if this is true about the DJ Jeeps but every Jeep I have worked on, the front and rear shackles for the leaf springs are the same length.

Rear shackle measures 3″ from bolt to bolt.

Here are the lift shackles. 5.5″ for a 2.5″ lift in the front. What is interesting is the bottom holes for adjustment.

The holes are 1.5″ spaced so I can cut these long shackles down and make a normal 3″ long pair.

Just that easy!

No more Carolina Squat for this Jeep.

The DJ Jeep is a 4 drum, manual braking system. Very basic but it works well and with only 100 HP and 2200lbs of curb weight, the drum system will work fine. We are just going to rebuild what is there.

DOT 5! Interesting. DOT 5 is a silicon based fluid instead of the typical glycol based DOT 3, 4, 5.1 stuff. It has some interesting advantages over the glycol based fluid. DOT 5 does not absorb water like glycol based fluids, thus brake systems don’t rust out. Downsides are that it can’t be used in ABS systems. Both are not compatible with each other so we should stick with DOT 5. Maybe future car builds I should switch to DOT 5… I mean look at that master cylinder, just some dried out silicon fluid, no rust!

I cleaned out the master cylinder with some denatured alcohol and then flushed the entire system with the denatured alcohol. This gets rid of any residue and water that may be in the lines. I then took all the soft brake lines out and used compressed air to blow out the rest of the alcohol.

I then popped the drums off the brakes with a drum puller. Highly recommend getting a drum puller like an Astro 78830.

This is what the brakes look like before disassembly. Make sure to take pictures!

To easily remove the springs get a Lisle 44800 Heavy-Duty Brake Spring Tool.

It screws onto the springs and grips them. I find it easier to remove the bottom spring first and then the top 2 springs on drums. After disassembly, clean all the parts with brake clean. Replace the drum cylinder with a new one and install a new rubber line. On all the surfaces where metal rubs on metal, apply some brake grease, don’t need a lot.

Reassembly is reverse of how it came apart. Make sure that self adjusting cable goes on correctly. Put the top two springs on before the bottom spring seemed to be the easiest way.

The outside of the drums I hit with a wire brush to knock off surface rust and then hit them with an anti corrosion spray. It will eventually bake off but atleast keeps them from rusting more for now. I want to eventually paint these drums.

Then fill and bleed the system with fresh DOT 5. This DOT 5 fluid had a dye in it so it was easy to know that the rest of the alcohol was flushed out when the purple DOT 5 fluid showed up in the vacuum bleeder.

Brakes tested and they work!

The throttle cable on the DJ was previously damaged and been repaired a couple times. This is causing the cable to grab and not allow the carburetor to close.

The replacement cable I was able to find was close in length but needed a different end for the carburetor.

Cut off the original end and put on this ball end for the cable. This just clips onto the carburetor.

Since I replaced the radiator, the transmission cooler lines needed to be removed. I dunked these in the ultrasonic cleaner to get the grunge off.

One of these lines is not like the other! A line was made from a converted brake line. The rubber of that hose was all gummy and starting to fall apart. I ended up replacing it with some barb fittings and a piece of transmission cooler hose.

I noticed while running the engine, that the oil pressure gauge never seemed to move once running. It was sitting at ~30-40lbs of pressure. I read on Porsche 924 forums that the oil pressure of these engines is supposed to be high. Looking in the service manual we have.

Cold idle should be around 100 PSI! 30 is much too low. But before figuring out if there was an oil problem or bearing problem, lets just check the gauge and sender. The gauges on this jeep are old and probably way out of calibration.

Measuring the sensor off the back of the engine with a multimeter I was reading ~140ohms at cold idle. The service manual has a way to calibrate the oil pressure gauge and specifies two points.

So 140ohms would be around 110psi. Looks like the engine is happy with oil pressure! Will have to figure out what is up with the gauges. I am betting that the ground for the dash has a bad connection.

It ended up just being some dirt in the gauge preventing the needle from moving.

The original radiator looks to have been clearanced with the cooling fan at one point, the seal at the top of the tank is split, and the brackets are pretty rusted.

Instead of trying to fix up the original radiator, I looked for a replacement. The DJ doesn’t share a radiator with the CJ chassis of Jeeps. The front opening is smaller on the DJ. A couple companies make replacement radiators but not for the DJ-5G. The Audi engine flipped the sides for the intake and outtake for the radiator and was the only engine for the DJ that was like this. Safe to say, no one makes a direct replacement for the G model.

So I ordered a radiator for the other models of the DJ that is made by “KKS”. If you search around for “KKS 3 ROW ALLALUMINUM RADIATOR FIT 1966-1974 Jeep DJ5 CAR 1966-1974 3.8L 4.2L” you will find it.

The radiator fit perfect into the opening but we need to hook it up!

This is a diagram of the Porsche 924 cooling system.

And this is the cooling diagram for the DJ-5G. I wanted to look at these cause the backside of the block has a coolant passage that then runs into the intake to heat up the fuel mixture.

The lower radiator hose was pretty easy to get hooked up with a Gates 25804 Vulco-Flex II Flexible Hose.

The back of the engine needed a hose block off and a some piece of heat core hose to get the intake heater hooked up.

Now the upper radiator hose is more of a problem. The cog for the cam timing prevents turning directly right. We can’t send the radiator hose over the engine because that would bring it above the coolant system above the radiator cap and would make bleeding the system a pain. This makes the only option to go down and to the left.

To join the hoses together, I cut some aluminum tubes and bead rolled them.

Now we can fill the system with coolant and bring the engine up to temperature. I set the idle and timing to 800 rpm with the transmission in drive with 10 degrees advanced. This is what the service manual specifies. The engine does seem to like a bit more advance.

This is the exhaust system that I welded together for the DJ Jeep. The only original part is the “bell” part which connects to the exhaust manifold.

Its just 2″ mild steel exhaust tubing and a tiny muffler I had in my parts bin. I did a side exit right in front of the rear tire to make it easier to make and not require more bends then I had tubing for.

I then did an oil change, cleaned/gapped the spark plugs, and cleaned and adjusted the points in the distributor. Oil is 20W-50 STP and a Purolator PL20252 oil filter.

I then cleaned up the air cleaner with a wire brush to remove the rust and then threw on some semi-gloss black paint. The fuel system is starting to come together. Fuel filters and some tubing into a gas can :)

The leaky valve cover ended up being a leak from the mounting points for the timing belt cover. Interesting that its open to the oil system. A random bolt threaded in stopped the leak.

With the cylinder head “rebuilt” its time to install it back on the block. I am using a FEL-PRO HS 8647 PT-1 head gasket set which has all the seals for the top end of this engine.

For head bolts I just reused the original ones. The service manual doesn’t say if I need new ones or not. Of course Porsche 924 forums say you absolutely need new ones :)

The torque pattern is normal but the engine has a 2-step torque step. You bring the torque of the headbolts up to the first spec, 65 ft-lbs, and then you need to run the engine and heat it up and then retorque the head bolts and bring it up to 85 ft-lbs.

Also, you should set the valve lash at the same time as it is required to bring the engine up to temperature to set the lash correctly. You will need two valve cover gaskets to do this correctly. So order a FEL-PRO VS50175C valve cover gasket set along with the head gasket set.

However at this point, I set the valve lash to 0.007″ on the intake and 0.017″ on the exhaust which is the factory lash for cold.

With the head and accessories installed, I set the timing of the cam gear and cylinder 1 being at top dead center. After checking everything out I tested the compression for each cylinder to see if we improved it.

Compression test:

1. 150lbs
2. 90lbs
3. 85lbs !!!!
4. 120lbs

From zero to 85lbs! Now this is no where near what it should be but should make it run better!

The valve cover looks pretty terrible so lets sand blast it and give it some fresh spray paint

It runs! There is a weird oil leak up on the front of the valve cover but it runs and doesn’t backfire. It starts easy as well. I won’t be able to bring it up to temperature yet as I need to get the cooling system working before then.

After a couple rotations in the the ultrasonic cleaner the cylinder head cleaned up nice!

Still some stuck on grime down in the oil galleys but this will be perfectly acceptable for getting it running.

What a stark difference between how it started! The ultrasonic cleaner really does a great job.

I am not going to mic out and measure this cylinder block. Lets just assume its all good ;)

Just going to give the valves a lap to clean up the valve seats since that is what I think is wrong with cylinder 3.

Some 120 followed by 240 grit valve lapping compound and a power drill made short work of cleaning up the valve seats. I think we may get this engine to run!

The engine went back together without much fuss. The Factory Service Manual the Jeep came with has this detailed out which made the reassembly smooth. The intake manifold was cleaned up in the ultrasonic cleaner.

When the cylinder block was getting ultrasonic cleaned, I soaked the cylinders in ATF to make sure the rings where loose and unstuck completely.

Then I cleaned up the deck of the block. In cylinder 3 I went after the rust that was deposited on the cylinder walls with scotchbrite. I managed to get most of the rust off. What is interesting about this block is the material. It is called Alusil which is an aluminum / silicon alloy. When they hone the cylinder walls they use a special polishing compound that can wear the aluminum but not the silicon. What is left is cylinder walls that are silicon which is very wear resistant. Should be able to remove the rust off the cylinder walls and leave the silicon walls…. or I wear through the silicon and the 3rd cylinder eats itself :)