76 240d Stalls when put in gear
 

I've got a 76 240d i drove it for two years on veg oil and bio, last year a piston blew and I have spent the past year rebuilding the engine. It is running now but when I drop it into gear it stalls out. I can drop it into gear with the rpms high and drive it but when I try to accelerate the engine bogs down and stalls. It is almost as if the engine is flooding. Is that possible with a diesel? Any advice would be appreciated

Thanks, lesson learned. Where do I go from here?

115.
I purged the fuel lines and it is better.
Now, the brakes barely work I just put a new diaphragm in the vacuum pump though so I don't think that is it. It is not blowing smoke like it would when the vacuum pump is leaking.

It is better but not great. The rpms surge when I take it out of gear and drop when I put it in gear. Then it levels back out.