hi there,

i apologize in advance if this is the wrong area to be posting this question-i'm new to the forum and have a very slow internet connection, making it difficult to explore/appreciate the site. i'll try to put in as much information as i can-please let me know where the best place to put this question would be!

i have a 1980 300 td wagon that had been run on diesel, biodiesel, and straight vegetable oil (always with at least 2 gallons of regular diesel per tank) by its previous owner. i've stuck to diesel myself, with two treatments of diesel clean to help clear out any gunk. it ran great, with just occasional stubbornness starting in the colder mornings until...

two weeks ago i ran out of fuel on the road (the gauge is unreliable because it was run on grease) but my buddy had straight vegetable oil with him- so i filled up and went on with no problems (supposedly the system self-bleeds and the filters were new.)

the next time i went to start it, starter spray was the only thing that got it going. when i try to start it, it doesn't turn over, even flooring it. the glow plug light comes on, but seems to take longer and longer (at least 45 seconds) both to reach the point where you hear the "thunk" of the solenoid and then after that to reach the point where it turns off.

i replaced both the prefilter and the main filter, trickle charged the battery, tested the resistance at the glow plugs themselves, and the tank is full of diesel from the one time i drove it after starting it with spray. the pump on the engine that you use to create the vaccuum in the line after replacing the filter works-i can see fuel in the clear prefilter. there's a bit of air in the prefilter too, but that's normal for this type of filter. there was at one time a nice racor filter in the line, but a mechanic detached that before i owned the car (have all the service receipts from the previous owner.)

at this point, it seems to me that the most likely problems are A) there is a clog somewhere in the system or B) there is air in the line (self-bleeding system might have been messed up when the engine was replaced, or at some other time in the life of the car)

i thought i'd ask for an expert opinion about the whole thing-i need the vehicle to work and don't want to waste time doing stupid things trying to fix it (plus its parked at my neighbors' and i don't want to intrude on them by working on the car longer than i have to.) am i correct in assuming that a clog or air in the line is to blame? is this really a self-bleeding system? where would the clog or air most likely be? (*the engine is from 1994)

thanks in advance for any help anyone can give in terms of where to post this or what to do next!

 

sorry, when i said the engine won't turn over, i meant that it cranks and cranks and doesn't catch and start. this is after the glow plugs have gone off and while flooring the fuel pedal

thanks!