Mercedes-Benz Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
85 Posts
Discussion Starter #1
After spending a few weeks out of town for work, I'm finally ready to wrap up the engine swap on my 1982 240D. I put in the replacement engine (with the tranny attached) without too much difficulty, now I'm ready to hook everything back up.

The replacement engine is from a 1979 240D. It has the older glow plug system--connected in a series. Do I need to convert this to the newer system in order to get the car to start? I think there's a good write up on diesel giant I need to find.

Right now, I'm reattached the radiator and have started to reinstall oil filter, hoses, etc. I haven't touched the fuel delivery system yet. Anything I should know?

I'm going to leave the AC compressor & pressure lines out of the car for now. Shouldn't be a problem, correct?

I'm anxious to get the car started well before the warranty runs out & I could use all of the help/advice I can get. :bowdown:
 

·
Registered
1984 300D
Joined
·
5,070 Posts
The 1982 Glow Plug Relay is different and made for one pin for one Glow Plug on the Connector. The individual Plugs from the Old system will burn in two if they get the Full 12 Volt directly so they all need to be connected up as they are.

I am not sure if you could simply connect a Jumper Cable to the very last Glow Plug Wire that would normally go to the Glow Plug Relay on the 1979 Engine because the trouble shooting chart shows only 9-10 Volts going into the Glow Plug series.
Perhaps the Head Lights could be turned on to lower the Voltage so a Jumper Wire could be used to heat the Glow Plugs and then the Glow Plugs Disconnected and the Lights turned off right before you try to Start.

Not sure why there is doulbe pics of the same thing but the Fire Wall end of the wire is the End that would go to the Fues and then on to the Glow Plug Relay that in the case of this type would have been behind the Instrument Cluster.
 

Attachments

·
Registered
1984 300D
Joined
·
5,070 Posts
If you are positive that your 1979 Engine has the Loop/Filiment Type Glow Plugs:
In the below pic is the contents of a Bosch FGR 2 Adapter Glow Plug kit; out of the Box.
Since you have the original 1982 Glow Plug Relay already on your Car you do not need the Jumper Wires.
You would completely remove the Loop/Filiment type Glow plugs and all of the wires from the 1979 Engine and the Glow Plug Ground wire (you would not need that any more).

Screw in the Adapter Glow Plugs (read the write ups on the Forums; everyone has that this is a good upgrade because the Adapter Plugs get hotter and faster) and connect them with the Wiring Harness you already have. And, I believe your Glow Plug light should work as it nromally did with the other later model Engine.

(The items in this Paragraph have been SOLD.)
I guess I am going to SPAM you as I would like to sell the set in the Picture. $45 + $3 shipping. Not shown in the Pic I have put Nuts and Lock Wahers on the Plugs. I tested the Glow Plugs on a Battery and the all tested Good (they are new).
In your case you will not need to use the Jumper Wires.

If you are anyone else wants to buy the Adapter Glow plug Kit Send me a PM.
 

Attachments

·
Registered
Joined
·
85 Posts
Discussion Starter #4
Thank you for this. It was tremendously helpful. I'm sure I'll have more questions. And I'm definitely interested in your glow plug kit. Will get in touch with you over the course of the next couple of days.

Is the kit basically the upgrade found in this article: Mercedes Diesel Glow Plug Repair (further down on the page)?



If you are positive that your 1979 Engine has the Loop/Filiment Type Glow Plugs:
In the below pic is the contents of a Bosch FGR 2 Adapter Glow Plug kit; out of the Box.
Since you have the original 1982 Glow Plug Relay already on your Car you do not need the Jumper Wires.
You would completely remove the Loop/Filiment type Glow plugs and all of the wires from the 1979 Engine and the Glow Plug Ground wire (you would not need that any more).

Screw in the Adapter Glow Plugs (read the write ups on the Forums; everyone has that this is a good upgrade because the Adapter Plugs get hotter and faster) and connect them with the Wiring Harness you already have. And, I believe your Glow Plug light should work as it nromally did with the other later model Engine.

I guess I am going to SPAM you as I would like to sell the set in the Picture. $45 + $3 shipping. Not shown in the Pic I have put Nuts and Lock Wahers on the Plugs. I tested the Glow Plugs on a Battery and the all tested Good (they are new).
In your case you will not need to use the Jumper Wires.

If you are anyone else wants to buy the Adapter Glow plug Kit Send me a PM.
 

·
Registered
1984 300D
Joined
·
5,070 Posts
At the DG sight apparently bought the individual Glow Plugs and made his own Wires; Bosch and Beru both make the individual Glow Plugs.

For some reason the Sets only come with 4 Glow Plugs.
There is the Bosch FGR 2 set that only has Plugs and the Wires and there is other sets that include a new Glow plug Relay that replaces the type that goes behind the Instrument Cluster.

Because the Kits were made for an Old Model Engine with an Old model type of of Glow Plug Relay the wiring setup you see on the DG site is for that.

On the DG site you are changing from Glow Plugs wired in a series where the last Plug has a Ground Wire attached to it (the Loop/Filament Glow Plugs are NOT grounded through the Glow Plug body where the screw into the Head).
And He shows changing to the Adapter Glow Plugs that are grounded through the Threaded Bodies in ends up wired in what I believe is called a series parallel type circuit.
No ground wire is used; if someone insists on installing the ground wire the Glow Plug Fuse will burn as soon as you turn the Glow Plugs on.

However, you don't need to connect them in a series parallel type circuit because you have your 1982 Glow Plug Relay and wiring harness already set up.
You just need to hook the individual Eyes to the individual Glow Plugs.

If all of the pic shows up it is just there to show the construction of the inards of the Old Loop style Glow Plugs.
 

Attachments

·
Registered
Joined
·
85 Posts
Discussion Starter #6 (Edited)
At the DG sight apparently bought the individual Glow Plugs and made his own Wires; Bosch and Beru both make the individual Glow Plugs.

For some reason the Sets only come with 4 Glow Plugs.
There is the Bosch FGR 2 set that only has Plugs and the Wires and there is other sets that include a new Glow plug Relay that replaces the type that goes behind the Instrument Cluster.

Because the Kits were made for an Old Model Engine with an Old model type of of Glow Plug Relay the wiring setup you see on the DG site is for that.

On the DG site you are changing from Glow Plugs wired in a series where the last Plug has a Ground Wire attached to it (the Loop/Filament Glow Plugs are NOT grounded through the Glow Plug body where the screw into the Head).
And He shows changing to the Adapter Glow Plugs that are grounded through the Threaded Bodies in ends up wired in what I believe is called a series parallel type circuit.
No ground wire is used; if someone insists on installing the ground wire the Glow Plug Fuse will burn as soon as you turn the Glow Plugs on.

However, you don't need to connect them in a series parallel type circuit because you have your 1982 Glow Plug Relay and wiring harness already set up.
You just need to hook the individual Eyes to the individual Glow Plugs.

If all of the pic shows up it is just there to show the construction of the inards of the Old Loop style Glow Plugs.
This is a great explanation. Your diagram clarified a lot. Here are the photos I mentioned:


 

·
Registered
'82 Euro 500SEL, '85 Euro 500SEC AMG WB Cabriolet,'86 Euro 500SEC RUF
Joined
·
9,487 Posts
Andromeda,
I just did this upgrade to a 1977 240 D. I used 4 Bosch 18mm (21MM box end wrench to remove),Durotherm Glow plugs and made jumpers, wired to the original strip fuse, ditching the ground wire. The original relay works well. but it will cycle at 15 seconds. I count 5 seconds and she starts. 10 seconds for an overnight start. Winter will tell.

The 240D's changed along with the 300D's in 1979 or 1980 to the smaller durotherm Fast glow plugs, so your harness will work and all you need is is the Fast glow plugs, but check your thread diameter to get the proper thread diameter glow plugs for your engine.

I should have done this upgrade a year ago.

Someone buy 300Dman's upgrade kit. pretty cheap for fast starts. Had I seen this before I bought my glow plugs(for almost the same money) I would have purchased this kit.
 

·
Registered
1984 300D
Joined
·
5,070 Posts
Andromeda,
I just did this upgrade to a 1977 240 D. I used 4 Bosch 18mm (21MM box end wrench to remove),Durotherm Glow plugs and made jumpers, wired to the original strip fuse, ditching the ground wire. The original relay works well. but it will cycle at 15 seconds. I count 5 seconds and she starts. 10 seconds for an overnight start. Winter will tell.

The 240D's changed along with the 300D's in 1979 or 1980 to the smaller durotherm Fast glow plugs, so your harness will work and all you need is is the Fast glow plugs, but check your thread diameter to get the proper thread diameter glow plugs for your engine.

I should have done this upgrade a year ago.

Someone buy 300Dman's upgrade kit. pretty cheap for fast starts. Had I seen this before I bought my glow plugs(for almost the same money) I would have purchased this kit.
His situation is different from yours where you were using the 1977.
Becaues He is putting the Older Engine into a 1982 Chassis the 1982 comes with a Glow Plug Relay (the Fuse is on the Relay) and Wiring Harness setup for the Pencile Type Glow Plugs.
All He needs to do is to connect His 1982 Glow Plug Wires up to the Adapter Glow Plugs.

I am not following the issues with the Threads. the Adapter Glow Plugs have the same threads as the Loop/Filament Glow Plugs do and should screw right into the Head with no issue.
Also the Wrench made fot the Loop/Filiment type Glow Plugs and the Adapter Glow Plugs is actuall 20.8mm (close to 13/16 of an Inch).
 

·
Registered
5 Speed "85" Euro TD , 5 speed "85" Euro 240D, "79" 5 spd 240D, 5 spd "94" Dodge/Cummins PU
Joined
·
664 Posts
Ah, thats why I had the 13/16 wrench in my tool kit, from when I had the big GPs:rolleyes:
 

·
Registered
1984 300D
Joined
·
5,070 Posts
I am posting this as a result of your PM to me.

Please look and see if you have a Glow Plug Realay located up front under the Hood of your Car where the Orange Circle is.

Next remove the Plastic cover and see if you have the Electrical Connector the Red Arrow Points to.

You won't have the the silver metal cylindrical object as that is somthing I added not made by Mercedes.
 

Attachments

·
Registered
1984 300D
Joined
·
5,070 Posts
In the picture below you should always have Battery Voltage at the places the yellow arrow points to. If you do not the Glow Plug Relay is not connected to the Battery.

I don't know if not having the other wires connecte will effect the Glow Plug Relay.

Some Glow plug relays have a wire that goes to an Engine Temperature Sensor.
But, your 1979 Engine may not have the correct Sensor on it for that. I believe that may be why the Glow Plug Lignt is not working.

You need to probe around with your Volt Meter to determine what is getting Voltage. If you do not have one Harbor Freight Stores sell the Volt/Ohm Meters for $6 or less. Get a Digital one.

The shiny metal strip on the Right of the Photo is a Fuse. If it is gone, burned, cracked or the Screws are loose the Glow Plug Relay will not work.

Make sure both Electrical Connectors are on the Relay.

If your Engine to Chassis Ground Strap is not connected your Starter is not going to turn. On mine the Ground Strap is under the Car on the Drivers side about where your Feet would be. It connects to the Transmission Bell Housing.
Also the Automatic Transmission has a Neutral Safety Switch. If that is not connected or the Shifter Mechanism is not correct your Starter Solenoid will not get Voltage.
 

Attachments

·
Registered
Joined
·
85 Posts
Discussion Starter #14
I will test the relays, fuse, and temp sensor connection tomorrow morning. I've connected the little black plug in that runs with the GP wires into one of the engine temp sensors (are both temp sensors supposed to connect? I only have one black adapter).

Will also connect the ground & NSS & come back with results.

Thanks all for tagging along with me on this Summer project. Hopefully I can get this thing running before classes start!
 

·
Registered
Joined
·
85 Posts
Discussion Starter #15 (Edited)
Looks like the harness that connects to the NSS has crumbled off, leaving 4 wires (2 pins, 2 bare wires) hanging. I tried reading the wiring diagram for the "starter lockout & backup light switch", but it's not clear on which wires go where on the NSS.

Edit: Found the missing 2 pins, looks like the harness will need to be rebuilt with a soldering iron (cheers to forming new skills!). Still looking for the color order on the wiring--would rather not short something out via trial & error.
 

·
Registered
1984 300D
Joined
·
5,070 Posts
I will test the relays, fuse, and temp sensor connection tomorrow morning. I've connected the little black plug in that runs with the GP wires into one of the engine temp sensors (are both temp sensors supposed to connect? I only have one black adapter).

Will also connect the ground & NSS & come back with results.

Thanks all for tagging along with me on this Summer project. Hopefully I can get this thing running before classes start!
One Temp Sensor goes to the Instrument Cluster for the Coolant Temp.

The other Temp Sensor was part of your Old Glow Plug System of the 1979 Engine; I don't know if that is useful for anything now.

I hope one of our members can tell you if your Glow Plug Relay needs to be hooked up to a temperature Sensor.
 

·
Registered
Joined
·
85 Posts
Discussion Starter #17 (Edited)
One Temp Sensor goes to the Instrument Cluster for the Coolant Temp.

The other Temp Sensor was part of your Old Glow Plug System of the 1979 Engine; I don't know if that is useful for anything now.

I hope one of our members can tell you if your Glow Plug Relay needs to be hooked up to a temperature Sensor.
Got the wiring set. The glow plugs work as they should. GP light turns on and off properly & the starter engages. The engine cranks ever so slightly, but nothing past that. I think there's a lot of air in the fuel lines. There's also very little pressure when pushing the plunger/primer. The inline filter is also mostly air, and just a bit of fuel. Should I bleed the diesel?

The vacuum lines are also connected (to the best of my knowledge)--the fuel shutoff valve, etc..
 

·
Registered
1981 W123 300D non turbo, 1992 190E 1.8 <=> 2.0
Joined
·
6,561 Posts
Bleed to the injectors.

Make sure you've got your throttle linakges sorted before you try (see your other thread!)

Make sure you've got a healthy battery.
 
1 - 20 of 20 Posts
Top