I hope everyone will keep me straight if my info is not correct or complete.

When mating the OM617 to a straight shift, there's only 3 required wiring issues;

1. starter motor - If your doing a conversion then you know how this works

2. glow plugs - either swap over the MB glow plug wiring harness and associated solenoid or rig up a ford starter solenoid with a push button on the dash or use the setup referenced by deck60

3. altenator - a GM single wire alt will fit in place of the MB alt with minor modification and is a popular choice. If you can mount the vehicle's existing alt to the OM617 then its a plug and play with the existing wiring harness. You can always keep the MB bosch alt and make an adaptor to your existing vehicle wiring harness but I think its only a 35 amp alt.

Most folks also want guages and are adapting the oil pressure and temp sensors from the existing motor over to the MB motor.

The tach is the most challenging in my opinion;

-Keep the crank sensor on the MB motor along with the round module mounted on the MB fender well and pull the tach out of the MB dash and fit it into the new vehicle.

-Keep the crank sensor on the MB motor along with the round module mounted on the MB fender well and buy a convertions module (there's a thread on superturbodiesel.com) to operate an aftermarket tach.

-Modify the alternator to drop out a sensor wire and use an aftermarket tach. (have read about this option on VW diesel forum)

 

maybe add another tach option to your list:
Tiny-Tach: Diesel Tachometers

fyi,
manny

 

The Tach actually seems like it's the easy part. From what I can tell off of the Jeep tech data the PCM take KPS input and generates a tach signal. So in theory all I should have to do is keep the crank sensor and the PCM should be able to figure it out from there.

So the plastic line from the manifold goes to the ALDA and is a good place for the boost gauge. The shut-off switch I've got needs to be wired to switched 12v and ground, and should have one line that goes to a tee from the vacuum pump and the second line goes to the fuel shut off valve on the IP. That should be it for the motor side. Then I need a few vacuum points and check valves off of the main vac line for truck side stuff. Probably using the vacuum reservoir is a good idea. And that should be it. I don't know what the heck I was hitting my head against yesterday. For some reason I kept looking over vacuum and electrical schematics and got all But it's not so bad now. Thanks guys

 

What are all of you doing about the deeper part of the oil pan being right where the steering parts are? Or is it just in the Cherokee that there is an interference problem? I have been wanting to do a swap like this for a while but could not see a way around the oil pan problem other then raising the body which I did not want to do.

 

A suspension lift seems to be the thing to do. I'm going to try just stiffer rate front coils first, then if that doesn't work I'll get the lift. I might also modify the lower pan. I'm kinda winging it right now as I'm no ready to test fit anything yet. I'm going to try to make my block plates for motor mount brackets this week. I was going to test fit the engine and mock up mounts this weekend, but a tree fell over at my parents last night, so I'll be playing lumberjack instead. The rough plan in my head is to get the engine as far back against the firewall as I can, even if that means shoving the trans back too, and see if that get's me anything. I would probably have been better off getting or building a remote mount oil filter to help with this, but I'll just make do. I never thought I'd say this, but a 3" body lift would be perfect here. But we're dealing with a uni-body, so no chance of that.

 

On my three MB 300D's the line from the rear of the intake manifold (connected with a banjo bolt) goes to the OP solenoid valve. From there a line goes to the ALDA (the red circle). Your picture doesn't look like the OP solenoid valves on my cars but it looks close enough that it probably is. I can't help with the numbers. BTW that banjo bolt on the back of the manifold is the one that needs to be cleaned. Make sure that the nipple into the hose is clear. Also be careful not to break the line as that plastic tends to get brittle and it is a real B---h to get back onto the nipple. Need to heat it and pray a lot. Not that I have had that problem. Riiiiight. The idea is that the electric OP sensor on the manifold will complete the circuit sending power to the OP solenoid which will shut off the pressure to the ALDA thus reducing the fuel to the injectors which will reduce the boost. The more pressure the ALDA sees the more fuel it will allow. The OP sensor cuts in just north of 11 pounds or so I'm told. Never had things set that high.

The yellow line is the fuel shutoff which is done by pulling a vacuum to shut off the engine. The MB ignition switch has both a vacuum section to do this and the electrical switch. Without that you will have to provide your own vacuum switch running off the line to the brake booster. The MB brake booster line from th vacuum pump on the front of the engine has a T incorporated for this as well as for the transmission to modulate the shifting.

---AutoMerged DoublePost---

The lift may be the least expensive way. The big problem is that the oil pump and pickup are both down in that deep part of the pan. A guy on the Okiebenz list went and machined a whole new pan for his swap out of billet AL. Didn't cost him much but time as that kind of thing is his day job. Wow what a job getting to play with high speed computer controlled milling and turning machinery all day. The last I heard I think he was still trying to find a way to get the oil pump to move up another inch or two

 

Adding a tachometer

Read through this thread and see if there was something you didn't cover in your tach setup. If it is still as easy as you were thinking, then please provide a detailed explaination as I would like to understand how to do this myself.

Thanks.

 

While the front sump pan is definately an obstical, it can be modified a little to help out. The oil pickup which hangs down the lowest is 4" back from the front of the sump. The bottom of the timing chain is in front of the oil pickup but it only hangs down less than 1" where the oil pickup hangs down apx 3". With a little bit of sheet metal welding, the small metal front sump pan can be easily modified to remove the front 3.5" down to 1" which may clear many of the steering issues. If the 1" front sump is high enough but you need a little more space toward the rear, then you can modify the oil pickup to move it either farther back or toward the front below the timing chain then modify the metal sump to fit.

The Kotch site offers a modified full aluminum sump with the front metal portion removed so that is an option also. Few of us have the access or skills to perform the milling from this thread but the mods shown in the first few posts are doable for most who have the skills to undertake a repower project.
http://www.superturbodiesel.com/std/...d.php?tid=1962

 

Walkenvol, the first pic in the link in your second response is pretty much what I am prepping myself to have to do. As I said I don't want to, but I my have to. I've seen those pics and a few from other swaps where the pan is modded for clearance. From looking at pics of this motor in XJ/MJ Jeeps that seems like it would be enough to get the pan out of the steering's way. Upgrading the spring rate is super important too. But I won't know on that until I get time to start test fitting parts.

As for the tach, I'm not sure what I could explain out further. Jeep takes a signal generated by the flywheel/crank sensor relationship, runs it through the PCM, and sends it to the tach in the dash. As I'm retaining the PCM for other gauge functions I'll just leave the crank sensor hooked up. The adapter kit I'm using retains the stock Jeep flywheel, so I'll still have the tone ring to trigger the sensor. Now the big trick will be to see if the tach reads accurately off the 5-cyl engine. If the PCM just interprets generically X.PPM=X.RPM, as some do, then it will be OK. But I'll burn that bridge when I get there.

 

My understanding was the jeep tach received its signal from the dist which would explain my confusion if instead it receives its signal from a crack sensor at the flywheel. How would you keep the PCM functioning without the stock engine? What year jeep are you repowering?