81' 300SD starts and then dies after a few seconds
 

ive been running it on veggie oil for a little while with absolutely no problems. however yesterday i noticed some smoke from the exhaust while on wvo and its never had smoke before. anyways i got home, purged the lines as usual and accidentally ran out of fuel so i did get some air in the lines.

currently my diesel tank is out of the car and im just using a half gallon container as my diesel tank to warm up the engine, then switch to the veg tank in the trunk. and i have clear fuel lines so i can see whats going on and where the air is.

i pumped the priming pump to remove all the air from the lines, and could see that diesel was coming from the tank, to the ip, and was being returned back to the tank.

cranked it over and it started just fine, it will idle for maybe 2 or 3 seconds and then it just shuts down. i can also rev the engine up but even with the gas pedal to the floor the rpms start dropping and the engine stalls after about 5 seconds.

i checked all vacuum lines and everything's connected like it should be. its very odd that it would just all of a sudden not start on me like this. any suggestions?

Fuel filters.

just put new ones in today. its still having the same problem. heres a couple videos i shot of the problem in action

http://www.youtube.com/watch?v=8jE78xkQJAA
http://www.youtube.com/watch?v=d_NSfATGWMM

chec screen in fuel tank

It's not getting fuel. Pull the injectors and check them individually.

try disconecting your vacuum line for shutoff switch on pump and try.maybe your ignition switch went bad that lets vacuum pass thru and shut off your engine. good luck

got it started, i took off the oil cap and it held an idle. i was able to drive the car home with the cap on loose but naturally there was a ton of oil all over the engine by the time i made it home. i took off the cap once i parked with the engine still running and there was a ton of blowby. also if i pulled on the throttle linkage a big white cloud came from the exhaust. with the engine warmed up i replaced the oil cap and the engine continued to run.

still not sure of the original cause of this problem, however. i plan on driving the car a little bit tomorrow to see if i can replicate the problem and try to narrow it down. ive replaced the breather hose from the air intake to the valve cover, my old one was cracked and taped back together but i dont believe it was the cause of the issue i was having.

Have you checked the oil level? Is it over-filled?

Although it really sounds like when you pumped the lines you perhaps still didn't have them completely full of diesel and now it's just run through and you're getting fuel.

hello
i would suspect that you are either having a worn fuel pump due to using old wegy oil or slight crack on the pump that draws air inside system....

the oil level is right in the middle of the two notches. i got all the fuel out, im just concerned that i will get stranded somewhere if this issue comes back. yesterday i drove about 40 miles to the boneyard and back to pick up some parts, and had no issues. no smoke and it seems to be running great now! its just very strange that i couldnt get it started due to too much pressure in the engine, and had to drive home with the oil cap cracked to relieve the pressure.

I think the oil cap deal is just a coincidence. I really think the problem was lack of fuel/air in the lines.

here is some video i shot right when i figured out what the problem was. i am 100% sure it is not related to air in the lines.

http://www.youtube.com/watch?v=BTjvO5HS7qM
http://www.youtube.com/watch?v=R9jqvWW3Br4

Well, huh. That's pretty conclusive.

How about this: open up your air cleaner and pry the little tabs up on the top of the trap. Make sure it's clean in there and that air can flow from the breather on top of the cam cover all the way to the air cleaner unobstructed.

I also noticed that the glow plug relay light on your dash isn't coming on.

By the way, I hope you feel better, that sounds like a nasty cold.

Had a simular problem with my old gal. Would only start for 2-3 sec. and shut off. It was a accident that I took off the cap. My problem was that the previous owner had put a after market intake and rerouted the breather to a "dip stick looking tube" that goes towards the bottom of the block. replaced with the OEM intake, now runs like a charm. check the tube going to the air cleaner, if you pull that instead of leaving the cap loose you won't get the oil mess!!!