Mercedes Forum - Mercedes Benz Enthusiast Forums

Mercedes Forum - Mercedes Benz Enthusiast Forums (https://mercedesforum.com/forum/)
-   Diesel Discussions (https://mercedesforum.com/forum/diesel-discussions-33/)
-   -   starting 81 300D (https://mercedesforum.com/forum/diesel-discussions-33/starting-81-300d-11379/)

grdda 05-10-2006 10:21 PM

starting 81 300D
 
Help---
I purchaesd an 81 300d that WAS running; the owner apparently got fed up with ongoing problems ( the alternator was obviously recently replaced; new fuel filters; brakes were rebuilt with new booster unit, etc) and a friend with a towing service picked it up for me. He said that it essenetially ran out of fuel after being driven onto his lot. After getting it home and putting fresh fuel in it (was bone dry), I primed it, released the banjo fittings on the fuel filter to purge air---would not start. Fiddled with the fuel system (the filters had recently been changed); I checked the hose conections for obvious leaks. While priming, the lower fitting that connects the pump to the filter leaks significantly ( fuel drizzles out); the pump itself seems fine and makes that reassuring "squoosh" noise that I recall from my first, and new(!) 81 240D. The return line looked suspect, so I replaced them. Removed the gp and injectors for visual exam, nothing obvious. Resistance in each gp was <1 ohm. Attached each gp to 12 v supply and each glowed. Checked voltage at each pin in the gp relay, and all had 13+ v during timed sequence (~45 seconds).
Put everything back together, and still no luck, even when manually advancing the throttle beyond the "stop" point. Also cracked the injection piping at each injector, and had small flow while turning over engine.
Questions:
1) Huh?
2) the vacuum system looks like it has cracked fittings, hoses that go nowhere and some that are plugged with a machine screw---will the engine fire without a functioning vacuum system?
Whatcha think?

sleepwalker 05-10-2006 11:04 PM

RE: starting 81 300D
 

will the engine fire without a functioning vacuum system?
Whatcha think?
yes. the vaacuum is needed to shut engine off.

carnut 05-20-2006 04:02 PM

RE: starting 81 300D
 
Assuming the engine is turning over at the proper speed, I would have someone crank the engine while you spray WD40 into the intake. A diesel must have proper cranking speed to fire.

carnut 06-01-2006 10:13 PM

RE: starting 81 300D
 
It also must have compression within spec. Low compression and a cold diesel will be a bear to start.


All times are GMT -5. The time now is 06:26 AM.


© 2024 MH Sub I, LLC dba Internet Brands