ALH - Ran out of fuel, can I prime injection pump without vacuum?

I made a stupid and ran it out of fuel, I put fuel in and attempted to start with cranking to no success. I don't have a vacuum pump and have no way of getting one. How can I prime the system without a vacuum pump?

Take the T out of the top of the fuel filter, fill the filter with diesel, reassemble. That should work unless you have an air leak somewhere. Be careful you don't pinch the O rings on the T. A little Silicone lube of some kind would be good for those or a bit of motor oil or even some diesel smeared on the O rings.

Be ready for an extended (longer than normal) period of cranking.

I'll give that a shot, I just have to go grab more diesel since I poured all 14 litres into the tank.

I've always used a vacuum pump of some sort.
Read this thread....
http://forums.tdiclub.com/showthread.php?t=485928&page=2

It really shouldn't be that hard to find or borrow a vacuum pump of some sort.

I have heard of guys, in an emergency, creating a vacuum with their mouth carefully but that is not something I would do or recommend.

I have also primed diesel systems by slightly pressurizing the fuel tank at the filler cap in order to force fuel out the lines to the pump.....if you do this you obviously need to take the return line off the pump so that the air can escape that is being displaced by incoming fuel.

Careful you don't loose the mickey mouse clip. Just pull that clip and that T will pull up out of the filter with the hoses still attached.

Get a jug of PowerService (Silver/gray bottle), make sure the top of the filter is CLEAN (you DO NOT want to get ANY crap in there!) and fill the filter, then replace the "T" and put the monkey clip back in.

If you can crack an injector line (#3 is preferred since it has the needle lift sensor although it's not mandatory) that's preferred. Wrap it in a towel so it doesn't spray fuel all over the place.

Crank until you get fuel at that injector. DO NOT crank for more than 20 seconds or so at a time, giving the starter a good 5 minute rest between them to cool down.

When you have fuel at the injector line nut you cracked, snug it back up and it should start. It may start very rough for a few tens of seconds or so, but it should start.

Well, I've primed the Injection Pump with a 12 volt tire pump. You have to observe the clear fuel hose for air. As soon as you see air, stop the pressure ......... and then fill up the filter and repeat. Of course, you have to pull the input hose to the filter (apply air pressure at the "IN" nipple on the filter), leave the return hose off, plug the return nipple on the Thermo-T and pinch or clamp the return hose from the filter...

I did the above at night with ambient at 22F and wind blowing.... pretty tough task, but it worked. (I now own a hand operated vacuum pump).

Due to the fact that air compresses and fuel does not, you may want to crack more than one hard line loose to bleed the air out. Once the engine fires off it will pretty much get the non-firing cylinders going almost right away.

I've never used a vacuum. Long clear hose on return port from IP and suck. Then crack an injector or 4, put down some rags and crank briefly.
Please don't drink the diesel!

Tools needed: 17 MM or 11/16 wrench.

Remove Mikey Mouse clip and fill filter.

Remove return fitting. This will allow fuel to flow through the pump easily. Crank engine until you get a good flow of fuel. Tighten fitting.

Loosen nut at injectors. Crank until good fuel flow. Tighten nuts.

Start engine.

^That would do it^
Your system won't be completely empty, what I described was what I did when I changed the pump.

whitedog said:

Tools needed: 17 MM or 11/16 wrench.

Remove Mikey Mouse clip and fill filter.

Remove return fitting. This will allow fuel to flow through the pump easily. Crank engine until you get a good flow of fuel. Tighten fitting.

Loosen nut at injectors. Crank until good fuel flow. Tighten nuts.

Start engine.

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Last July, north of Madison, Wisconsin, I was running low on fuel but there were no good exits due to road construction (exit after exit). So, finally a good exit and I took. Several tight right and left turns from the down ramp to the service station pump.

Well, I filled-up and then the engine would not start........ obviously, it sucked air in all those turns as the tank was near empty (Vanagon).

Using the tools (& lots of paper towels) and method you listed is how I got it going!

Vacuum is NOT the best way to prime the VP 37 injection pump. Due to the design of the hydraulic circuitry (as opposed to earlier VE pumps) when the injection lines are loose at the injectors and vacuum is applied to the pump housing, some air will be pulled into the open injector line (the pump does not have positive check valves in the hydraulic head. Therefor the best way to prime any VP 37 equipped fuel system is to use pressure. See the below instructions (this is what i send to all of my customers who purchase pumps, or my reseal service)..

PRIMING THE PUMP. The best way to prime a drained pump when installing it back on your engine is with pressure (NOT VACUUM). This is a simple task and is very effective. After installing the pump back on the engine reconnect all lines EXCEPT for the supply hose at the front of the pump (this hose comes form the filter to the front of the pump). The injection lines should be connected to the pump and injectors, and tightened at the pump, but DO NOT TIGHTEN the lines completely at the injectors (finger tight). Now take a squeeze bottle (an empty gear oil bottle with a short piece of 1/4 inch fuel hose attached works very well. Fill the bottle with clean fuel and attach it to the open pump inlet, then slightly loosen the return line fitting form the top rear of the pump so that air can vent out of the threads (just loosen it a turn or so). Now start squeezing the bottle until you see fuel dripping from the loosened fitting (you will hear air "squeaking" out before you see fuel). Keep squeezing the bottle until you see fuel coming out of one of the injector lines (it will be the #1 line if the crank hasn't been rotated form TDC after you installed the timing belt, but it doesn't really matter). Once you see fuel out of one line, tighten it, then rotate the crankshaft clockwise until you see fuel coming from another line, then tighten it. Do this until all 4 injection lines are tight. Your pump, lines, and injectors are now full of fuel and your engine will start very quickly now (the system is completely primed. IF YOU REPLACED YOUR FUEL FILTER AT THIS TIME, use the exact same method described above but connect your squeeze bottle to the filter rather than the pump. You can also use an electric fuel pump if you happen to have one laying around.

dieseldrive said:

Vacuum is NOT the best way to prime the VP 37 injection pump. Due to the design of the hydraulic circuitry (as opposed to earlier VE pumps) when the injection lines are loose at the injectors and vacuum is applied to the pump housing, some air will be pulled into the open injector line (the pump does not have positive check valves in the hydraulic head. Therefor the best way to prime any VP 37 equipped fuel system is to use pressure. See the below instructions (this is what i send to all of my customers who purchase pumps, or my reseal service)..
PRIMING THE PUMP. The best way to prime a drained pump when installing it back on your engine is with pressure (NOT VACUUM). This is a simple task and is very effective. After installing the pump back on the engine reconnect all lines EXCEPT for the supply hose at the front of the pump (this hose comes form the filter to the front of the pump). The injection lines should be connected to the pump and injectors, and tightened at the pump, but DO NOT TIGHTEN the lines completely at the injectors (finger tight). Now take a squeeze bottle (an empty gear oil bottle with a short piece of 1/4 inch fuel hose attached works very well. Fill the bottle with clean fuel and attach it to the open pump inlet, then slightly loosen the return line fitting form the top rear of the pump so that air can vent out of the threads (just loosen it a turn or so). Now start squeezing the bottle until you see fuel dripping from the loosened fitting (you will hear air "squeaking" out before you see fuel). Keep squeezing the bottle until you see fuel coming out of one of the injector lines (it will be the #1 line if the crank hasn't been rotated form TDC after you installed the timing belt, but it doesn't really matter). Once you see fuel out of one line, tighten it, then rotate the crankshaft clockwise until you see fuel coming from another line, then tighten it. Do this until all 4 injection lines are tight. Your pump, lines, and injectors are now full of fuel and your engine will start very quickly now (the system is completely primed. IF YOU REPLACED YOUR FUEL FILTER AT THIS TIME, use the exact same method described above but connect your squeeze bottle to the filter rather than the pump. You can also use an electric fuel pump if you happen to have one laying around.

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That is not how the priming is done with a vacuum pump. The hard lines are tight. It's after the pump is full of fuel is when the hard lines are opened. Usually only one or two while the car is being started.

What Jokila said, but I have a small, inline diesel-rated fuel pump (clip-on leads) that works exceptionally well and quickly. It goes inline between the fuel feedline to the filter and the filter, connect clips, wait until it stops (full pressure), crack an injector, crank until you get fuel, snug it up and Bob's Your Uncle.

If you have it with you in the trunk and run out of fuel it makes re-priming quite easy and fast -- as long as you have a wrench to crack an injector line.

Dieseldrive, lots of folks have successfully used the hand-held Mityvac to prime their Injection Pump.

As Jokila noted, the nuts on the hard lines at the injectors (and IP) are not loose during the priming process. Once the IP is primed, simply cranking the engine over with the nuts loose on the Injectors expels the air out of the hard lines..... tighten the nuts and the engine will fire-up right away!

jokila said:

That is not how the priming is done with a vacuum pump. The hard lines are tight. It's after the pump is full of fuel is when the hard lines are opened. Usually only one or two while the car is being started.

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Thats my point. The vacuum system doesn't prime the lines at all which means (the pump has to fill them).The pressure method fills the pump and lines completely full of fuel, so the injection pump doesn't have to. Try it, you'll be amazed at how much quicker the engine starts.

dieseldrive said:

Thats my point. The vacuum system doesn't prime the lines at all which means (the pump has to fill them).The pressure method fills the pump and lines completely full of fuel, so the injection pump doesn't have to. Try it, you'll be amazed at how much quicker the engine starts.

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I suppose if i had a battery operated pump i could do that. It's easy to buy a miteyvac at a local parts store. I use the miteyvac to bleed brakes, test vacuum operation of hoses, so it's really a useful tool.

The vacuum method will also diagnose bad IP seals because a hand vacuum pump is usually no match to overcome a leaky pump. I am talking about a leak that doesn't actually lose enough fuel, if at all noticeable, but will let the fuel system lose it's prime as fuel siphons back to the tank.

dieseldrive said:

Therefor the best way to prime any VP 37 equipped fuel system is to use pressure. See the below instructions (this is what i send to all of my customers who purchase pumps, or my reseal service)..

Click to expand...

I had to change the fuel filter on my old VW pickup on the road once.
I had a GM fuel filter for the 350 Olds diesel, only inlet & outlet lines.
I took the return line off the pump and blew into the tank.
When fuel started trickling out of the pump I put the line back on quick.
Loosened the injector lines and jumped the starter solenoid until I saw fuel coming out and stopped.
Tightened the lines, cranked it several seconds and it started.

The only thing I don't care for with your procedure is not running the bottle of fuel through the filter.

If you suck from the tank and push through the filter you will find it's the superior method to priming the entire fuel system... you can either use a 12-volt pump or you can use a marine primer bulb, both are very effective... I found the best way is to loosen all four injector nuts and also loosen the return banjo cap nut and the case pressure control valve... operate the pump until you see clear fuel coming from the connection between the case pressure control valve and the quantity adjuster... When you see clear fuel, the filter and the pump are bled completely, tighten the case pressure control valve, the return banjo cap nut then crank the engine with the pump still running... Once fuel is squirting from the injectors tighten the injector nuts... at this point the engine will start with just a few revolutions

wonneber said:

I had to change the fuel filter on my old VW pickup on the road once.
I had a GM fuel filter for the 350 Olds diesel, only inlet & outlet lines.
I took the return line off the pump and blew into the tank.
When fuel started trickling out of the pump I put the line back on quick.
Loosened the injector lines and jumped the starter solenoid until I saw fuel coming out and stopped.
Tightened the lines, cranked it several seconds and it started.
The only thing I don't care for with your procedure is not running the bottle of fuel through the filter.

Click to expand...

I should have added "clean fuel". You can also do the squeeze bottle method into the filter.

The vacuum method will also diagnose bad IP seals because a hand vacuum pump is usually no match to overcome a leaky pump. I am talking about a leak that doesn't actually lose enough fuel, if at all noticeable, but will let the fuel system lose it's prime as fuel siphons back to the tank.[/QUOTE]

Not sure I understand. If there isn't an abnormal restriction, your vacuum pump should never achieve a significant negative pressure (If it can pull fuel from the tank). If you do have a restriction pre-pump, pulling a high vacuum on the pump housing CAN pull air around a good drive shaft seal. This is a lip seal that is designed to hold pressure in the pump, but doesn't have the ability to hold a lot of vacuum (even on a brand new seal). Even worn seal will usually seal under pressure, but can allow air into the pump when the engine is not running.

I understand that many, many people have success using the vacuum method, but that doesn't mean that there isn't a better way.

BTW - I always replace the drive shaft seals when resealing these pumps (TDIinjectionpumps is my Ebay user name).

I have always used an old 90 weight bottle with the tapered fill cap on the end (I have also used a dawn dish soap bottle with the pull up cap pulled off). I fill the bottle with diesel, jam the rubber inlet hose onto the bottle top, remove the return line on the pump and squeeze away until fuel comes out the return line. If the car still will not start then I crack a couple of lines at a time and let them bleed out a little while cranking. Tighten the lines down and it should fire up with a few more cranks. I can't beat the price and if you don't have a spare bottle just buy a new 90 weight bottle or bottle of dawn dish detergent and put the contents in something else until you need it.

I had an interesting bleeding occurance last week. Pulled fuel through the filter and figured I was good to go. Cranked, fired, died. Oh well. So I hooked up the Mity Vac to the return line and pulled up to 15 inches vacuum with no fuel flowing. OK, so I loosen the clamp I have on my hose on the return fitting and as soon as it opened enough, fuel and air rushed out and filled the MV bottle. Well, that was interesting, so I did it again and got the same results. So I cracked two lines and put a blue towel over them and cranked until they we're squirting, tightened and fired it off.

So why the fuel coming out only when the vacuum was broken?

Whitedog, could the hose be collapsing internally, creating a plug?

As many of you know, I've been driving VW diesels since January, 1980.

I've never had to prime the IP due to sucking air as a result of changing the fuel filter. I always plug the hoses and/or clamp them shut, fill the filter as full as possible, and then install the new filter and connect the hoses................ Then, I start the engine and take RPMs up to about 1800 to 2000 for at least two minutes. Never once have I lost Injection Pump prime following that procedure. Yes, sometimes the engine sure acted up, but I kept it going with more throttle.

I probably could have got on the throttle and kept it running but I was overconfident and just swing my leg in to step on the clutch and by the time I got over to the throttle, it had died. Eh. I just deal with it. It's what I get paid to do.