Engine started..coughed, shuttered and then died under load.

[Duke1]

Hello,

My car is a 1978 W116 300SD with the 5CYL 617.950. I've done a lot of reading on this site and have learned quite a bit.

Here's what happened to me this morning. I just did a valve adjustment yesterday and found several were tight. After adjusting all valves to spec..I took the car out and it ran even better than normal.

This morning I was taking my in-laws to the airport and I fired up the Benz, and let it run for a minute. As we came to the bottom of the driveway, (inclined) I placed it into LOW to get moving and it started to get jerky, sputter and finally quite after moving about two feet. I tried to crank it again and while it wanted to catch...no joy.

This has caught me by surprise...the car ran great the day before. Am I correct in assuming it's a fuel issue? The GP light came on, and the car fired right up this morning as usual. Plenty of fuel (over 1/2) and I just changed the primary and secondary fuel filters about two months ago.

I did notice today that when I went to see if I could use the primer pump to see of I had some issue with the filter not having enough fuel in it, It's the old style and it didn't do anything but go up and down..and never seemed to make any suction.

Please let me know what else I should be trying.

Thanks,
Mike
Duke1