Jeep Grand Cherokee

I am going ahead with converting a 1993 Jeep Grand Cherokee to diesel using a 6.2. I have the engine in, it is a tight fit and took some massaging of the sheetmetal. I still need to fab some engine mounts and get everything aligned right, but it appears to fit, barely!

Couple Questions.....for now.

1. Can I use the in-tank fuel pump to replace the mechanical? I need to remove the mechanical pump as I believe it will interfere with the engine mount. The engine mount has to be farther forward due to the front differential trailing arm mount. Or should I just buy a lift pump from a 90s truck?

2. To gain some hood clearance, can I use a turbo style intake? My thought is to run a tube to an air box. I have the old intake off my K3500 6.5, but I need the hat.

3. For the cabin heater, can I run my heater hoses in and out of the left & right ports on the rear of the heads? Extra cooling when the heat is on :)? Or how can I use the port on the front crossover like in the GM truck, as the Grand Cherokee radiator does not have a port for the heater return.

4. Does anyone have a photo of the "V" belt routing on a 6.2 with AC? Photos of brackets?

As this project progress I will post more info and pictures. It is still in a beginning stage and I am trying to get everything to fit. The PS pump is a close fit and the hose piping will need some reworking to fit. I plan to use the hydroboost and MC from the truck and eliminate the ABS on the Jeep. It should get real interesting when I get to the wiring. Hopefully I can transfer most of the Grand Cherokee wiring.

The plan is to try and use what I have around here, 6.2, and a 700R4 from a 1983 2500. I want this to be a "budget build". I am still looking for a transfer case I can just bolt up. I am having the trans redone but I do not plan to redo the 6.2. I have an extra 6.2, 1985 military van, (it had a rod knock and then stopped running while idling one day when I went to move it, now appears to have locked), behind the barn which I can take parts from, which has already proven useful. Someone put new heads on it, but I think they did not put it back together right as almost every bolt I have taken off was partially lose or only hand tight.

Thanks in advance for your help. Any other ideas or input is appreciated.

Hans H.

Too bad you are so far from me. I have a 4L60 trans with a transfercase I'm trying to sell. Would work well behind a N/A 6.2.

On to the questions.......

I don't think your current intank pump would do well. The pressure is too high, and may not be compatible with #2. You could rig a pressure relief, but LP's are not too expensive, and the added points of failure may not be worth the headache. If you have to switch to an electric pump, be sure to incorporate a fail-safe. A late model oil pressure switch and relay will do this well, or you could get the complete package from JK, but it won't be a budget purchase. You will also have to include a return line back to the tank, if it doesn't already have one.

I would not use the turbo intake. The cross section is too small for N/A, and would create more restriction than a larger, more open N/A intake. You'll probably have to fab your own, which isn't to hard. It isn't rocket science.

Pulling coolant from the rear of the head(s) will starve the cylinders of coolant flow. You'll have to get the heater line off the pump, like it is already.

No V-belt photo, but I think there are some in the Photo Album.

There are a bunch of transer case options. Be sure to compare the driveline output sides before you commit to one. It would be pretty discouraging to find they don't match, after it's too late. Which side is the diff? It may narrow your options. I have both, but shipping would negate any advantage. The tranny adapter and spline will also have to match, and they are dependent on the tranny.

Sounds like a fun project. Good luck!

With the 700R4, go look for a NP241 transfer case. It will be a driver's side front output which is what you need for the ZJ. They are installed in the IFS GM/Chevy 4x4 trucks and should be plentiful in wrecking yards.

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Originally Posted by JeepSJ

With the 700R4, go look for a NP241 transfer case. It will be a driver's side front output which is what you need for the ZJ. They are installed in the IFS GM/Chevy 4x4 trucks and should be plentiful in wrecking yards.

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Exactly what I was thinking or a NP231, but I think the NP241 is more HD.

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Originally Posted by HH

Exactly what I was thinking or a NP231, but I think the NP241 is more HD.

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Correct. 241 was used in the full sized trucks and the 231 was used in the mid-sized trucks - S10, S15, etc...

The 6.2 is bolted in and ready to go......well almost. Still have to put in new trans and sort out the electrical & linkage issues. The swap has been pretty straight forward.

Still need to work on a couple items.

1. Can I put a switched 12volts to the pink wire, which goes to the 2 pin coolant sensor and then to the IP? How does this work with the cold idle? I am planning to tap into the Grand Cherokee's hot coil wire.

2. On this 1983 6.2l engine the fuel line going from the mechanical pump to the filter on the rear of the engine there is a bulge in the fuel line with a wire? I assume this may be a "water in fuel indicator", and if so how does it work and how should I run the wire? If not what is it for?

3. Can I plumb my heater return hose into the passenger side port on the waterpump or should I "T" into the one between the waterpump and thermostat? Or do I need to "T" it into the upper radiator hose?

Thanks for the help.

Guess I have not updated this in a while. I have the engine, trans, and TC all mounted and fit pretty good. Real close on the PS pump and exhaust manifolds, about 1/2" clearance here, and 1/2" clearance there...

I am using a 700R4 trans and a 241 TC. The engine is a tight fit. I had to massage the firewall a bit to get it where I wanted. I would have liked it a bit more 1/2" or so to the passenger side, as the stock engine is offset that way. It ended up pretty close to the centerline of the vehicle. Some custom exhaust manifolds might have made this a little easier.

Interferences I had to deal with included the firewall, steering gearbox, and the control arms. The front differential moves to the passenger side as it comes up. The way I have it now the driver side control arm is very close to the exhaust manifold on full compression, I intend to either extend the bump stop or add a budget boost. It is also close to the oil pan, I think if I hit a large bump it would leave a mark.

The motor mounts were the hardest part. The 5.2l engine has mounts at the front of the engine. I made some flat plates welded to square tube which mounted to the engine and the frame mounts. The frame mounts were out of the pickup I took the engine from. I trimmed them and flipped them over to fit the Jeep.

I replaced the manual fuel pump with a GM diesel electric pump from a 1993, can always share parts with the K3500. The manual pump was in the way of the engine mounts. I could put plates on front of the engine like a drag car, but I am trying to use what I have.

The fittings from the diesel PS pump worked with the ZJ PS box, with some rebending and fitting. I used a hydro-brake booster from a diesel van, and got rid of the ZJs ABS. I had to make a mount to make the hydro-boost and master cylinder fit. Made some new brake lines and adapted them to the stock lines at the point where they came out of the ABS block.

I was able to use the TC linkage with a little modification, I had some linkages off a Cherokee that bolted to the TC and worked with the ZJs shifter, what luck! It appears to work OK.

Over the last month, I added a deep trans pan, added trans shifter linkage, ordered a shift cable, mounted the engine and trans oil coolers and ran the hoses and lines.

Had to run the engine oil cooler lines up the back of the engine and over the top around the radiator and AC condenser. Added some cooling holes to the bumper (150!) and front fascia.

Here are a couple before and after pics of the coolers. Not much longer and it should be ready to fire up.

Packaging is always difficult! And you have less room to work with than I did. Looking good so far!

Nice, almost did that to a lifted 94, but realized the straight six would cause it to roll a little to the right when you hit the throttle and wondered what would happen with more torque.

I put a 5-speed in it, but never got ambitious enough for a Diesel. Should work well though!

Installed the trans shift cable the other night. Used a 6 foot universal cable from B&M with threaded ends. Bought a spring loaded quick disconnect end for the shifter side. I found a quick disconnect that fit the ball socket on the stock shifter at a marine supply store, had two choices, of course the first was wrong. I made a mount for the cable out of some 2" angle and secured it to the floor. The mount on the trans was from B&M. Ran the cable through the stock location and reused the firewall grommet and heat protection. I used the stock shifter lever and linkage. I had to do a little grinding to get the shifter to move far enough so I could get the transmission in first, it would have worked fine the way it was, but IF I ever need 1st it will be nice to have.

Here is a link to a rough write up and more photos of the Diesel Jeep.

Have not done much since August, back to work full time and working at the second job also. Been playing around with the wiring. Bought a converter from Dakota Digital to convert the signal from the flywheel to the signal the computer is expecting, 8p/rev. Bought a sensor that will count the teeth on the flywheel, send the signal to the Dakota Digital box and then to the Jeep computer. Decided to mount the batteries in the rear and run the battery cables along the frame rail up under the wheel well into the battery box.

I picked up some great used Firestone tires 215/85R16 and mounted them on Ford 16" Aluminum rims. Looks like I will have to trim the front bumper slightly. I also picked up some 3:07 gears for the rear Dana 35.

My hope is to get this fired up and running before winter, but working the two jobs and some freelance work is making it tough.

http://www.syntheticwerks.com/images...l288_8873a.jpg

Did some work on the Grand. Ran the battery cables to the rear battery and installed the Jeep's oil level sensor in the pan. I drilled a hole in the pan, then welded a 3/4 16 NF nut to the pan about 6" from the top and about 8" from the rear. While I had the pan off I inspected the block and could not see any cracks, ya-hoo!

She fired up today! Lots of little things to do. Just ran some temporary wiring to run the lift pump and the shut off solenoid. Now to do all the little things, and run an exhaust, should be interesting.

Great to hear! Going to have any video links?

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Originally Posted by 6.5 Detroit Diesel

Great to hear! Going to have any video links?

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Sorry no video, the ex took the video camera. :(

The Jeep drives under her own power! Took the ZJ for a lap around the driveway last week. Still have exhaust to do, and some wiring. Redid the oil pan tonight, small leak in the back. Seems to be burning a little rich, may be gunked up injectors or just old worn out injectors, would have been easier to change when the engine was out. (#$%^?) Smokes a little while running, blue smoke.

Changed out the fuel injectors, but have not run it yet to see if it runs less rich. Ran out of time last week.

Ran some exhaust from the manifolds to the muffler. Still need to do two tail pipes. Used 2.25" and 2.5" pipe and a Dynomax muffler with two 2.5" inlets and outlets.

Also hooked up a solenoid with a momentary switch for the glow plugs.

More info and new photos on my Diesel Jeep page.

http://www.syntheticwerks.com/images...6_exhaust1.jpg

Some more updates on this project. Cleaned up the wiring, with some zip ties and loom. Used a Dakota Digital signal converter to get a marine tach working and the speedometer working. Installed some relays to power the lift pump, and the shut off solenoid. Fixed the fuel level sender, had to bend the float slightly as it was hitting on the pick up line I installed in the tank.

The hood is installed and does not hit anything. I thought I would have to install a slight bump to make it fit. Hopefully the accelerator cable will be OK. It appears to be the only thing touching the hood.

Need to still find a wheel to match the other 3, and some lug nut that are all the same. Tie down the battery and make a cover. I am going to run it a bit and then change out the fuel filters.

Been a while since I updated this. Time seems to have gotten away from me. Too much to do...work, school, weather has been a bitch :(. Barn roof partially collapsed in Feb when we had 18" of snow. ...but I have done some more work on the Grand.

We changed the gears to 3:07s. Took it out for a test ride. Drives great....except the front brakes are getting hot. Changed to a master cylinder for a 1/2 ton truck because the van one was leaking anyway and made the pedal real hard. Better pedal, but no improvement with front brakes. Think I found the problem, the shaft going to the hydroboost was rubbing slightly because of the angle to the pedal. Lowered the hydro boost and master and the shaft does not bind. Front brakes seem to be on the warm side, but not smoking now.

Next problem crops up with a few more miles of testing. I am out for a test drive to put some miles on it and I get the death wobble. First I changed the lower control arms and increase the caster, but still had the problem. Next, I changed out the right side ball joints (very little play), track bar (very little play in one end), and steering stabilizer. I am running the 215/85/r16 LT tires at 40 psi. All appears good now, no death wobble on last test rides.
Plan to drive around more in the next couple weeks.

Now on to fix the K3500.....and the barn roof will be priority the next couple months.

How time flys. Replaced the trusses and roof on my barn last November. Did some small things on the Grand last spring, new calipers on the front brakes, and wiring. Still has some electrical gremlins, but the Jeep is drivable. Found out the gas gauge reads about 1/8 when it runs out of fuel :( At least it was in the driveway close to the barn. Been driving the Grand around and have put about 3000 miles on it. If my speedo and odo are right I am getting 22 - 22.5 mpg.

Nice to see progress! Keep at it.

Filled up the other day and calculated 24.75 mpg....I'll take that. We'll see on the next tank, but I can go almost 600 miles on a tank of fuel.

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Originally Posted by HH

We changed the gears to 3:07s.

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Best fuel economy will come with a combination of 1800-2000 rpm and 65-mph. Generally, 3.42 diff gearing, a 700R4 OD and 30" tall tires work well.

Thanks for keeping us up to speed on your project!

Jim

Running ~1700 rpm at 60 mph, and can run at 1400 rpm at 50 mph if I can keep it in 4th gear and the converter locked. Tires are 215/85R16 at 40 psi, could run up to 60 psi.

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Originally Posted by HH

Filled up the other day and calculated 24.75 mpg....I'll take that. We'll see on the next tank, but I can go almost 600 miles on a tank of fuel.

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When my wife drives she can get a bit over 40mpg out of our 93 Grand.
I of coarse get closer to 35 mpg. ;>)

http://www.canev.com/cherokeeConversion.php

Last three tanks...

24.9 mpg
25.1mpg
25.9 mpg

So I'm averaging just over 25 mpg in an SUV that used to get something like 12 mpg.

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Originally Posted by HH

http://www.syntheticwerks.com/images...6_exhaust1.jpg

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If I may make a suggestion. Having an exhaust crossover pipe as close to the exhaust manifolds as reasonably possible will help to improve both performance and fuel economy, and it'll make the engine's exhaust quieter.

A light-duty 6.2L non-turbo engine can get away without a crossover pipe if the engine is using a light-duty intake manifold with EGR passages. This allows the exhaust impulses to equalize side to side, improving flow. If given the choice, I'd rather use a crossover pipe instead of putting more heat into the intake manifold.

Thanks for the update. Jim

Might have to try and squeeze one in there. The exhaust is a bit loud.

Best mileage to date has been 27 mpg, seems to average about 25.5 - 26 with regular use.

Died two weeks ago on me. It started, then ran rough, and then stopped. Had to use some WD40 and a fresh charge on the battery (yes only one) to get it started. Appears to be some fuel leaking around the IP at the point where the arm pivots near the bottom. Also found the water pump is leaking. Guess I have a small project now that it is after Christmas....Going to add a second battery now that it is cold too.

Moving on ... to a new diesel, 2007 Jeep Grand Cherokee with the 3.0 liter diesel. But going to keep driving the K3500 and Savana 6.5s for the heavy duty jobs.

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Originally Posted by HH

Moving on ... to a new diesel, 2007 Jeep Grand Cherokee with the 3.0 liter diesel. But going to keep driving the K3500 and Savana 6.5s for the heavy duty jobs.

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Did you sell the 6.2L converted Jeep Grand yet?

Casey

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Originally Posted by arveetek

Did you sell the 6.2L converted Jeep Grand yet?

Casey

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Nope, hanging on to it! Still drives good. I had an unscheduled job change and needed something more reliable and comfortable for my daily 76 mile ride (38 each way). I was also looking for a 2 door Tahoe/Yukon. I have been averaging about 25 mpg, got just over 26 mpg for 2 tankfuls, but now we are on winter diesel.