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1996 E300D how long to self-prime fuel lines

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4K views 8 replies 6 participants last post by  Al_Savage  
#1 ·
Hello All,

I have a 1996 E300D that I just replaced all the low-pressure, plastic diesel lines and O-rings. I also replaced the fuel cut-off solenoid valve. I did not replace the fuel filter (yet). I had to do that to fix a nasty diesel leak in that area.
I took great care to make sure I did not get the lines mixed up. I believe all the vacuum tubes and electrical connectors are in place.
The car won't start. I believe it's due to lack of diesel fuel in the lines/cylinders. I have cranked it over probably 20 times now with a jumper cable attached. Some of the low pressure lines look like they have diesel in them and others look empty.
How long should the self-priming process take? How can I determine if it's working properly?
Any advice will be greatly appreciated! Thanks!
 
#2 ·
The fuel lines are gravity assisted, so if you have more than 1/4 of diesel in the tank, that would help.

Jack up the rear of the car so the nose is pointing downwards, then crank.

If you're feeling particularly brave, pressurize the gas tank 5-10 psi with compressed air and then crank.
 
#3 ·
I tried it 3 times already and it works.
Give the car tilt forward. Even slight tilt will play big role.
Than top-off the tank with diesel.
We had all fuel lines replaced on one job and the engine started on the first crank, only hesitating for about 15 seconds.
Dry fuel filter might take few seconds to fill, but I rather make few extra starter turns, than risk injector contamination by filling up the filter.
 
#5 ·
Make sure you have the large o ring on the primary filter. If you forgot it the car will never start. You can suck out most of the air by sucking on the return line port on the back of the filter housing using a minivac. When the obvious bubbles are sucked out, plug the return line back in and crank. When I changed my shut off valve it still took some cranking to get the air out of the injector pump.
 
#9 ·
I just replaced all the low-pressure, plastic diesel lines and O-rings
After replacing all my low-pressure lines + the SOV + filters + tank strainer, I used my Mityvac 7400 7.3 Liter Fluid Evacuator on the return line and it left NO air bubbles in the lines. Nice!

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I've had this 7400 for about a decade, and it is SO HANDY. Added too much transmission fluid? No problem. Want to remove the PS fluid or brake fluid from their reservoirs? This is the tool.

Well worth the $70.