1984 300SD hard to start after 45 minutes of sitting.

[noah123]

Hello, I hope someone can help me. Thank you in advance.

If my '84 300SD sits for more than about a half an hour, it becomes hard to start. When it does start, it makes quite blast of inky smoke.

The glow plugs are working.

I put the battery charger on it in the morning to help with the 30 seconds or so of cranking it takes before the engine fires up. When it does start and I shut it off before it has a chance to warm up, it starts right up again cold. (The engine block heater is plugged in when the car isn't being driven.)

I thought my old style extraordinarily leaky hand primer pump was the problem, so I put in the new style Bosch hand primer pump and replaced the fuel filters, but the problem hasn't changed at all. Pumping the hand primer pump while cranking doesn't seem to help it start any faster.

It does start right up if I only wait a few minutes after it's been shut off, and it runs fine, no excessive smoke.

There aren't any external leaks, nothing dripping fuel since I replaced the hand primer pump, could it be an injector leaking?

I'm the second owner, it was dealer maintained by the original owner and now has 226,000 miles on it. I change the filters and oil every 3000 miles or so. I use Rotella. I don't use any fuel additives.