I'm new here so pardon if this has already been discussed somewhere else here? Couldn't find it exactly. Also, new to this car, all other diesel's I own are trucks.

I've got an '84 300SD that I run 3X per week all Winter here in Central NY.
It has been a great car and running fine up til First week in January. Yes, its gotten colder but even in 40F weather car still wont fire. It was firing just fine even down to 20F.

Glow plugs are working fine (have power) and I use some gasoline and kerosene as anti gelling.

It will fire on Ether and once it starts car runs just fine and when I turn it off I get about 30 minutes up to an hour and car still fires right up, otherwise back to square one of just engine turning over with no firing.

I am thinking its sucking air and leaking in the lines somewhere but have checked and re-checked and replaced most of the lines.

I've even pushed the hand pump several times but it "sqeaks" right off the bat and I see fuel coming out of the return line immediately. It seems like it is getting fuel but just won't fire.

IF car sets for say 1.5 hrs, it wont fire BUT I can keep cranking on it while pedal is to the floor and it eventually fires up without Ether.
Overnight forget about it.


I have no block heater hooked up currently. There is a place for one with no wire attached. Can I simply buy an aftermarket coolant heater 600W or is the OEM one work better? Where can I get the plug for it. Currently has a 2-prong deal with what looks like one of those fittings you push it in then screw it on over??
Can I get aftermarket plug?

I don't see this as being the primary problem however. ??

Car wont start even today at 50F.

thanks for any insight.