Hello everyone!

I've recently come across a 1981 240D (~180k miles) that I will be picking up on Wednesday for the princely sum of $0. Of course, there's a catch...

The car does not run. The current owner (a friend of mine) purchased it with the intent of repairing it, but he is mechanically disinclined and quickly paled to the idea. When I learned he was planning on sending the car to the wreckers, I offered to take it instead. So on Wednesday, I'll be hauling it off to another friend's shade-tree garage to see if I can't revive it. The trick is that I've got about 2 weeks after I move the car to either get it mobile or get it gone.

I've gotten plenty of grease on my hands in my day, but it's all been gasoline engines. I know in principle how a diesel works, but I've never touched one. That's why I've come here seeking some advice.

Here's what I know from the current owner:

1) The engine turns over but does not start.
2) The original owner claimed the car stopped running due to a "timing issue."

I cringed hearing #2 after #1, since I immediately pictured pistons slamming into valves or some kind of catastrophic detonation. But again, I have nothing to lose here so I might as well have a look.

On a spark-ignition gasoline engine my course of action would be pretty clear, but there's a few things I'm unsure of with the diesel (how do you sync the fuel pump & injectors to the crank & cam without a timing light or somesuch, for example). So I'd like to ask here if there's any immediate gotchas I should be aware of, and furthermore if all of you recommend any particular manuals, web sites, or other places for information? I appreciate any help you can provide. Hopefully I can keep this car from heading to the junk-heap!

 

Make sure your Engine and Transmission have lubrication before starting.

If you do not have one Harbor Freight stores sell inexpensive Volt/Ohm (Multimeters). Take a look at the Diesel Giant web site and he has a pictorial on how to check the glow PLugs. (This is not an endorsment to buy his for sale items that are in my opinion extremel overpriced.)
After you have changed the Filters you will need to prime and get rid of the Air out of the Fuel Supply System and the Fuel Injection part of the system.

Sticking out of the side of the Fuel Injection Pump is the Fuel Supply Pump. It has a Hand primer (make sure you have Fuel in the Tank).
(In the pic to between and to the left of the #1 and #2 on the pic is a Banjo Bolt; loosen that ; it is the part that the fuel returns through.)
If it is an Old Style one with a shiny Aluminum body it will have a hard plastic knog that you turn counterclockwise to loosen.
Grab the Know and pull and push it up and down to pump the Fuel Through the System. You will need to keep pumping until you see Fuel with no Air coming out of the Banjo Bolt on the Return Fuel System.
When you get fuel up to there tighten the Banjo Bolt and for good measure pump a little more. Afterwhich, push the Hand Primer all the way down and srew it in clockwise a snug it down.
If your Hand Primer is a new styly one that has a black rubber coating on it all you have to do is push that up and down to make it pump.
If you are not getting Fuel up to that loosened Fuel Return Banjo Bolt you have some other issue like a plugged Fuel Tank Screen. However, I would expect to be using the Hand Primer a lot as after sitting a long time the Fuel has drained back to the lowest level.

Next you need to bleed the Air out of the highe pressure Fuel Injection portion of the system. This is done by loosening all of the Fuel Injection Tubing Line Nuts at the Fuel Injectors. (If you run completely out of Fuel you would need to do this also.)
You simply crank the Engine until you see Fuel coming out from under all of the Fuel Injectors.
After that tighten the Fuel Injection Line nuts and go through your Glow Plug Cycle and attempt to start the Car.

If it does not start after that report back here for more help.

 

Nice, thanks both of you for the tips, especially the picture (makes things much easier to follow).

I'll let you know how it goes tomorrow.

 

Hello again.

Just an update; I verified on Wednesday that the valve cam indeed turns with the engine, so I'm confident the timing chain is not broken. Further discussions with my friend revealed that the original owner told him that it was not just a "timing issue" but more specifically that "the injector timing was off." As far as I know it's driven by a gear, just how off could it possibly be?

First and foremost today, I checked the fuel path using the tips you guys suggested. Using the primer pump, I can get fuel to come out of the banjo bolt without a problem. Furthermore, cranking the engine with the injector cap nuts loosened indeed vents fuel. Fuel is getting all the way to the injectors without trouble as far as I can tell. I realize this was the priming procedure after replacing the filter, but I did not have time to go get new filters today. I will replace the fuel filter tomorrow and re-prime the system. Also, in addition to the canister filter that is easily visible near the top left of the engine, there is a smaller in-line filter down near the primer pump. I am assuming this will need replacing also? (Please let me know if I am wrong.)

After checking fuel delivery, I checked the glow plug system. The strip fuse is intact and has < 1ohm resistance. I get +12v from each pin on the relay when I turn the key to the on position, so that seems good. Continuity on the leads to the plugs is good, and I got +10v at the head of the plugs (I attribute the drop to corrosion/rust on the threaded plug heads where I attached my tester leads). When I checked resistance on the glow plugs, however, I got bad results. The first two were < 1ohm, but the third was ~33 and the last was wide open (no connectivity). Obviously at least one of the glow plugs is completely bad. I pulled them all and will replace them.

After I removed the plugs, I went ahead and laid a rag in front of the plug holes and cranked the engine to verify the injectors were opening, and I got nice gusty blasts and a diesel mist for my troubles, so the injectors don't seem fouled up as far as I can tell.

The glow plug issue raises some questions though; will one bad plug prevent the engine from starting? Also; it was around 80 deg. F. today. I have always been told that glow plugs aren't really necessary on warm days, but again I have little experience here. Is this true?

New fuel filters and glow plugs tomorrow, unless I hear something different from you guys. I'll let you know how it goes.

 

If the car is a poor starter, it is entirely possible that the valve adjustment has been sorely neglected. You may want to check compression, or just adjust them to be on the safe side.

 

Hello everyone.

I had a couple hours to get back to the car yesterday and I've done a little more work. I should also note I found out the car is an '82, not an '81 (though I don't think that makes too much difference).

I've replaced the fuel filters (both the spin-on canister and in-line filter, but not the fuel tank screen) and replaced all the glow plugs. After bleeding out the fuel system and trying to crank it, it's still no-go.

Here's the run-down when I try to start it:
- Turn the key, wait for the right-most lamp on the dash indicators to go out (the cover with the symbols is missing, I'm assuming that is the glow plug lamp). The lamp goes out rather quickly (3-5 seconds).
- Turn and crank the engine. The engine turns smoothly, and will occasionally give a hiccup like it's about to catch, but never does. Generally it will just turn and turn. There is a *tiny* amount of smoke produced from the exhaust, but just wisps. I can catch a whiff of exhaust smell on the air, but it's just a hint.

I have yet to check the cylinder compression; I need to find a 12mm adapter for my gauge. When I find that, what number am I looking for on this engine with 136k miles on it? I figure after I get numbers for compression I'll think about adjusting the valves (assuming it even gets close to running).

Additionally; the fuel primer pump is a little leaky under operation. I've since read elsewhere that this can be a problem since air may be sucked in from the primer pump with a bad seal (even when the **** has been tightened down). The pump is the "original" style with the aluminum body and plastic **** that you turn. Should I just go ahead and replace this?

Also, when operating the primer pump I will eventually get fuel bubbling out from the large center bolt on the spin-on filter assembly (the one labeled #1 on the picture that Diesel9112 attached). Is this simply the pressure relief or is this a leak to be concerned about?

Thanks for the help so far. Any further advice is appreciated.

 

It seems you have fuel so it probely won't help you on this but if I need a starting aid or help getting an unprimed engine running I use WD-40 it won't hurt the motor. Use the tube and pull a vacuum hose off the intake and spray some in. My 87 300D doesn't have a primer pump so when I changed all the hoses and filters WD-40 helped get it going with out cranking the heck out of it for the manual pump to do it. I also use it for 2 cycle engines also. With someone else cranking the motor you can keep it running with out hurting the motor. Just remember diesel motor rpms are set by fuel delivered so just spray on and off to keep the rpms you want.

 

lwbrewer, thanks for the tip. I am beginning to doubt my earlier optimism about fuel delivery. I had a friend spray in some WD-40 while I cranked the engine today, and it very nearly ran on the WD-40 alone. So I suspect that there's a fuel delivery issue after all.

My agenda for tomorrow is to replace the "soft" lines that connect the fuel tank line to the primer pump assembly and also connects the spin-on filter assembly to the fuel tank return. The upper line seems ok, but the bottom line is rotten with fuel and one of the ends looked a bit chewed up. I will also be replacing the primer pump itself (but not the assembly), and the braided return lines between the injectors and to the spin-on filter assembly. The only lines I'm not touching are the rigid plastic lines that run to and from the injector pump, since they look fairly decent besides color. Should I remove and replace these while I'm there just to be safe?

Also, I'm still wondering about the fuel coming out from the center of the filter assembly. With everything closed up, operating the primer pump will cause fuel to come out from under that large bolt (the one labeled #1 in Diesel9112's photo). Is this a genuine leak or the pressure relief?

Any other ideas are appreciated. Thanks!

 

An update for y'all: After replacing the lines and primer pump and closing up the bolt on the fuel filter, I was able to get the car started!

Ran it for about 10 minutes, everything was great until it blew the water pump (gah!). So, that's the next job on the list. Any tips or pointers on this before I dive into it? I ordered up the parts from NAPA, and the pump looks really weird to me, so I'm not sure if there's something I'm missing.

On another note: While it was running I drove it around the yard a little bit. The car is a total slug to get moving. I know diesels aren't exactly renowned for acceleration, but this seemed really bad. Now that the engine is running, I'm definitely going to look into the valve adjustments to see if that will help performance a bit. What else should I be looking into as far as tuning goes? I'm wondering if I'm now running into the injector timing issue the original owner was talking about? Any advice on this is appreciated as well.

Thanks for the suggestions so far, the thing is saved from the wrecker's yard for now.

 

The 240 is a very small motor and is a slug especially without the turbo can you get some pictures for us