W115 220/8 220D - Not Firing

[NWLondoner]

Hello all,

I'm still new so please bear with me as I navigate this forum.

I have recently had issue starting my W115 220D, but being in England, UK I knew that our abysmal weather could be a contributing factor. Recently though, it has been very warm (29°C/87°F) but my attempts were in vain.

It was on the old style wiring system so this was upgraded using a thread I found here and I purchased a new battery (just to be on the safe side).

It is still not firing.

I know this car has suffered from an oil leak in previous years before my ownership but I'm unsure if this could be a contributing factor.

Any help would be appreciated

[Mike D]

First things first.

#1 with any diesel is compression. Have you done a compression test? If your compression is too low it doesn't matter what adjustments, filter changes, fuel flow, glow plugs, etc, you do.

Start with a compression test. Compression good? 235 PSI/ 16 BAR MINIMUM across the board and 300+ PSI / 21+ BAR preferred.

#2 Check valve adjustment.

#3 Ensure the glow plugs are activating. Which style of glow plugs did you change to? The "pencil" type? Did you convert to the relay/timer system as used in the W123's or are you still using the "gorilla knob" manual pull?

[Diseasel300]

Moving back to basics, since the car sat, is the fuel system primed and ready to go? If it's aired up it isn't gonna do a whole lot. Have you cracked an injector line to see if it's pumping fuel out to the injectors?

[Mike D]

Originally Posted by Diseasel300

Moving back to basics, since the car sat, is the fuel system primed and ready to go? If it's aired up it isn't gonna do a whole lot. Have you cracked an injector line to see if it's pumping fuel out to the injectors?

Good point. I was working under the assumption, as stated by the original post, the car had been running until recently when the starting problem began. We know how assumptions can go.

[CTD]

The Diesel engine needs compression and fuel. If one of those two things is missing or inadequate, then it will not run. I'd make sure that no fuel lines/filters are blocked, that the IP is primed and working correctly, and that the engine has adequate compression.

[vox_incognita]

NWLondoner,have you managed to get the starter turn(I read your previous threads).Are you getting voltage at the starter terminal 50(the smaller threaded connection) when somebody has pulled the gorilla knob to starting position(clean connections first).
If not,you can jump the terminals like on this pic(observe safety rules)...

...and report what happens.

If the starter seems to be working with terminals jumped ,check the connection between terminal 50 and the respective terminal @ the gorilla knob body.If it's alright then broken wire(or bad connection) from ignition switch might be the problem.
Anyway,you can always install a separate starter switch in the car.

BTW the ballast resistor on mine is bypassed(although still in place on the firewall).A 50A fuse box is installed.

Check this first ,because from the other threads of yours it seems that the starter simply refuses to turn.

After that you'll proceed with other possible culprits...