Priming a diesel that has run out of fuel.

[hheynow]

This is rather interesting. Just got an email from a biodiesel user group board where this guy had run out of diesel and devised a way to prime the fuel lines without taxing the starter or fuel pump. He drilled a hole in the fuel cap and inserted a valve stem for a car. Then he opened up his fuel drain valve, tightened the fuel cap and pressurized the tank. Once the fuel drain flow was without air bubbles he closed it then released the pressure from the valve stem. It started right up!

Comments?

 

[bushpilot]

seems risky...what pressure would you use ?
seems to me that you could easily blow the lines
at the slip on connections. how much pressure could
a plastic fuel tank hold up under ?

3-5 turns of the key, for 30seconds (w/out turning over
the starter) primes my system (after changing BOTH filters)...

as for TRYING to save the life of the fuel pump...it runs CONSTANT
(while driving) anyway...and its not necessary to crank crank crank
the starter to PRIME most modern (fuel pump based) diesels.

 

[JLDickmon]

Bushpilot is correct... most modern f.i. systems (gas or diesel) will autoprime by cycling the key.

 

[Tbar]

Sometimes on the 7.3's it can be a little difficult to reprime.............just open the drain valve and cycle the key until you get a good flow.........close and cycle again several times. No need for anything fancy.


Tbar

 

[roosterdiesel]

OBS guys don't have electric fuel pumps. Wonder if that has anything to do with the guys procedure?

 

[Yellowsub1962]

a lot of elec fuel pumps are NOT self priming. basically by pressurizing the tank then cycling the key once or twice will force fulel into the pump and it will then be able to pressurize the lines with a few key cycles. I've been doing this on my Willys (TPI 383 stroker) for years out on the trail.. even with a half full tank when I just about flop it on it's side if it gets a bubble it can lose prime. I just use a rag to block the open filler and blow the air right through it. I hear the tank "pop" (expand) and I have someone hit the key. works like a charm

 

[Wingdog]

a lot of elec fuel pumps are NOT self priming. basically by pressurizing the tank then cycling the key once or twice will force fulel into the pump and it will then be able to pressurize the lines with a few key cycles. I've been doing this on my Willys (TPI 383 stroker) for years out on the trail.. even with a half full tank when I just about flop it on it's side if it gets a bubble it can lose prime. I just use a rag to block the open filler and blow the air right through it. I hear the tank "pop" (expand) and I have someone hit the key. works like a charm

Me and my old man do the same thing on our 88 7.3L work truck when she runs out of fuel (it has a stock air valve on top of the filter). There is now way at all you will pressurize a rag enough to blow anything out, but it does get the fuel to the filter.

 

[Mike K]

We do the same compressed air trick here at work. Some vehicles dont prime that well, or sometimes the primer just doesnt work so we use the air trick. We have never had a problem.

 

[Scot]

I have never cycled the key multiple times!?! I always just started as I normally would after a filter change, no problems.

 

[bushpilot]

interesting...id think youd get at least SOME hesitation or rough idling
until the filter bowls fill up. fwiw you might be interested in knowing the
owners man. calls for cycling the key a couple of times.

I have never cycled the key multiple times!?! I always just started as I normally would after a filter change, no problems.