Hello all. I've got a '78 300d that I bought a couple of years ago off an old man in Las Vegas for $200 after it sat in a field for about 20 years. I changed the battery, fluids, filters, and the little manual hand pump style fuel primer and swapped to this style glow plug kit https://**************.com/store/early-300d-300cd-300td-non-turbo-glow-relay-manual-override-kit-w-upgrade-plugs and it started right up and ran like a champ. Replaced brake lines, calipers, and rotors and it could drive it out of the garage, although very slowly. Added trans fluid and it was running like a champ although very sloppy ride. Replaced the shocks and it was great. Then I parked it for about a year and only started it occasionally. During that time I moved to Amarillo Texas and had it shipped out to me with a couple of other cars. Other than a jump, the shipping guy had no issues with it. In Amarillo, I parked it again for about a year. After that, I moved to Dallas. A couple of months after that I went back to Amarillo to get it and the battery was dead. Checked it and it needed a new battery. Replaced that and it started up and ran great. Drove to Dallas on a single tank of gas going 80-85 the whole way with no issues. When we got it here it became the kids car for school and they drove it daily for several months with no issues. Then the daughter calls me one day and says she couldn't get the car started and they all had to walk to school. When I got home the battery was low, she said she cranked it for quite a while, so I jumped it and cranked it over. I cranked it for quite a while and between the jump car and some gas pedal pumping I got it started after a long crank. It died instantly though. I did it again and same result. One more time and this time held the gas down a bit and it ran with the extra fuel. I held it a few more seconds before releasing the gas pedal and it idled like normal and drove like normal. Next day it wouldn't start again. I went through the same sequence of events and got it running the same. 3rd day, same no start but this time it never got going. I have no history with these cars or diesels at all so I started researching and figured I'd start with the small stuff. The fuel lines between injectors would be damp after running the car so I replaced all those lines and the washers under the injectors. I also adjusted all the valves and measured the timing chain which turned out to have just under 4* of stretch. I don't know what the max allowed is but some guy said somewhere that 10* is when you absolutely have to get it done so I figured that's still ok but needing to get done. The fuse for the glow plugs is still good and I can hear the relay clicking when I engage it so I think the glow plugs are good, but no guarantees. Either way, from what I understand, if I crank it long enough it will get hot enough to start firing regardless won't it? I pulled the hard lines off the injector pump one at a time and they were each squirting, although it didn't seem like very much compared to what I was expecting. Thinking about it though, the injectors really wouldn't be spraying a whole lot so not completely surprising. At this point I'm at a loss. What's my next step? I've been putting the starter through hell so I'm starting to get worried about that a bit but I'm killing the battery so bad it's probably just that being low all the time.

First thing kids will be kids. If the idle adjustment is turned down on the dash for that year. They will be hard to start I found. I got the same call from one of our daughters I had loaned a 77 300d to. Many, many years ago. when she was visiting.

I asked her why she had turned it. Forgot the answer and was not upset. So easy a solution was present. Turned to low idle engine just does not get enough fuel to start. Now if it is not that the glow plug circuit should be checked. A little more difficult to check out properly than the newer cars if it still has the large loop glow plugs. Seems to me many of these cars want glow plugs. Sometimes even after the engine is warmed up. Before wanting to start.

There are other potential causes. The above to me are fairly common. Cab light dims with glow plug cycle means it is drawing current. Dash indicator means nothing on these early ones I think. Now if converted to pencil glow plugs. First check you can probably give the car a glow cycle. Read the temperature of each glow plug with a spot type temperature reading device. To find one or more dead ones. This is just a quick test.