Loop to Pencil Glow Plug Conversion
 

I've just ordered a conversion kit for my 76 300D (115). Does anyone know if the Bosch kit comes with instructions? If not, is it possible to wire these plugs into the existing circuit such that the glow plug light and ignition swith will function as before? I had to order an extra plug with the kit for all 5 cylinders, will I have to get any other parts for the kit to work on my 5 cylinder?

I've searched the forumn but can't find any specific instructions on this conversion.

TIA for the help,

David

I did the switch on a 78 240D. The kit inlcuded decent instructions, but will not directly plug into any harness. You'll have to do a little custom wiring. I did a write-up on it at http://home.comcast.net/~phantoms/vacuum/index.htm. Unfortunately, all the large pictures were lost on a server change over and I didn't have them backed up.

Glow Plugs
 

I cannot speak for a W115, but i did the conversion on my 79 W123. There are two ways to do it, 1) convert you series setup (79 W123) to a Series/Parallel set up, this is done by removing the old glow plugs/wires and Grounding strap and installing the new plugs with new fabricated jumpers wires to each plug( Leave the Grounding strap off the last plug off,Cyl #1). This method will improve your starting immeasurably. I drove around for months like this and it worked fine, The problem with this is the plugs go off when the engine starts.
With the new relay kit the plugs stay on for 3 minutes after engine starts and this smooths out the idle untill the car heats up, works great. Because you car has five cyls you have to order the extra plug and you will need a extra relay to work # 5 cyl i think the part # is 0 332 002 156.
Yes, the kit comes with instructions.
I hope this helps but remember mine is a 79 W123.

I ordered the additional relay and an extra glow plug. Is the addtional relay used in conjunction with the relay in the kit or does it replace the one in the kit? I received the kit today and the instructions don't mention how to wire it for a 5 cylinder.

Thanks for all your help

Relay
 

If you have a 5 Cyl, then its its for the extra cyl, are you sure there are no extra instructions for the 5th cyl???:confused:

Nope, no 5 cylinder instructions in the fast glow kit. Just 1 sheet with instructions in 8 languages.

The extra relay will arrive in a few days maybe it will have some instructions.

Thanks again,

Gp
 

The extra relay won't have the instructions, that relay has many use's, I bought mine from a solar power store. My bosch kit came with 2 sheets with 8 languages,one for the 4 cyl and one for the 5 cyl, i can fax you a copy or we will figure something else out. You will also need to pick up some small parts from your local parts store, 25 amp fuse fuse holder..... the paperwork tells you what you need. I also picked up a small enclosure to house all the components so they are protected from the elements, if i could figure out how to post photos on this site i would show you, if you like i could take a photo of the instructions and encloser and email them to you(PM your email only). Anyhow i can hear the Panzer calling me..it wants its injector pump.:)

Thanks, you have a new PM

On my 77 I just replaced the plugs, removed the ground strap, installed the jumper wires between each plug and hooked plug #1 up to the existing relay system. I did this about 3 yrs ago and have had no problems at all. I don't see any real need to keep the plugs on after the engine starts since I don't have any post-start idle problems. Made a HUGE difference in cold starts (below 10 degrees fahrenheit)

Phantoms; is there a way you could post a larger version of the first image on your side here, tnx?

Sorry, as stated all the large images were lost on a server change. In fact, the whole page was lost and the only way it's there now is by the gracious help of users here who had archived it. The next time I'm around my daughter's car, I'll try to get some new pictures.

Your going through a lot of trouble for nothing. You dont need to replace the ralay.

http://dieselgiant.com/mercedesdieselloopglowplugrepair.htm

Got Glow, Now Wont Start
 

Well, I hooked the plugs up to the existing relay, they glow fine but I still cant get the thing started. A little history:

My daughter drove this car all last year before leaving for college in August. It sat in our driveway for a couple months before I started it and took it out for an hour or so and filled up the tank with fuel. Car sat some more until December when my daughter came home for Christmas. I tried to start it for her but couldn't, I wrote it off to cold weather. Let is sit for a couple more months and tried to start again, found an open (old loop style) glow plug.
Converted to pencil style but still no start.

I've taken out a glow plug and grounded it and turned the key to the glow position and the plug gets red hot instantly so I'm sure I got good glow plugs.

What's an easy way to check if it's getting fuel? It seems just on the verge of catching sometimes but won't kick over. Is it possible the fuel's bad? How would I tell? This car ran great all last year for my daughter, I'm at a loss as to why it won't start now.

TIA,
David

Running Finally!!!
 

Well after pumping the priming pump for what seemed like an eternity until I finally heard the buzzing noise and then pumping another full eternity, then cranking for about 30 seconds straight it finally caught and seems to run great. I'm letting it cool down now and see how another cold start goes.

I've never adjusted the valves on this so I think that's my next project and maybe a flush with the stuff at Diesel Giant.

I also need to replace my injector return hoses, as they're all weeping. Could that have been the cause of the air in the system (or whatever required so much priming)?

Final question: This is a W115 with an OM617 and I can't find any fuel pre-filter (the main filter is in a canister not a spin on), can I just add a pre-filter to this setup? Was there originally supposed to be a pre-filter?

Thanks again for everyone's help.

Yes, there is supposed to be a pre-filter. You can just splice in one of the L shaped prefilters from the later models.