sheriffav8r

I was driving home a couple of weeks ago and went from WOT to idle and the truck shut off. After having it towed by a friend (imagine a Toyota pulling a Dodge and the looks we got) we got it to my local shop. They went through everything and couldn't find the problem, but bled the injector lines and got it running. It happened again a few nights ago (with the wife on Valentine's day - talk about scoring points with the missus) and I researched what the problem was and how to bleed the lines myself. When you have the lines under high pressure and then back off the pressure instantly the VP creates a vacuum and stalls the engine since the injectors can't be operated with air. There are no instructions that I could find so I thought I would put it here:

Use a 19mm or 3/4 inch box wrench to loosen the #1,3, and 4 injector nuts on the engine. Count from the front to the back. Loosen them about 3-4 turns.

Crank the engine about 15-20 seconds until you see fuel coming out of the injector fittings. (No fuel equals bad VP-44).

Tighten the injector nuts.

Start the truck. You are basically starting the engine on 3 cylinders so it will sound rough at first. The VP-44 will then compress the fluid in the other lines enough to push the air out of the remaining lines.

Next time, don't rapidly pull your foot off the accelerator when at WOT....

And carry that 3/4 inch or 19mm wrench with you....

patdaly

I just start it with them loose, then tighten it up.

Leaks some, but works well since I usually don't have anyone to help.

Tate

Normally that is an issue for guys with big injectors. Surprised you got hit with it.

Just a correction, you will want an open end wrench, unless you have cut a slot in the box end to go over the line, which isn't a bad idea anyway. Then its a dedicated wrench that can stay in the glove box.

JD730

I've had mine start missing after doing that, but never had it shut down like that.

I've also had my 93 with a VE miss alittle after doing that same thing. But my pulling tractor, I've stalled it and then it didn't want to start right up afterwards, that had air in it. I'm not sure what causes it, but my theory is that the injector is in the middle of an injection event when you let off and the cylinder pressure is high enough to push some air into the injector tip.

sheriffav8r

Box end wrench, open end wrench, 220, 221, whatever it takes, heh, heh....

Southern Pride

thats funny, my truck did it the other day. i think it was either there was air in the lines, or couldve been that my gf ran the truck down way past 1/4 tank. she picked me up at the bar around 3am and took me home. was supposed to get fuel when she got off work, but forgot and in my silly state of mind, i didnt know what was goin on. woke up the next mornin and the truck wouldnt fire up. turned over just fine. put 5gallons of fuel in it, still wouldnt fire up. cracked the #3 injector and had my bud turn it over. pushed alot of air out then fuel and fired right up.

Southern Pride

also, my fuel gauge is off a bit. she always goes by the guage. she can drive the wheels off it, but cant seem to keeep fuel in it. told her how much a new vp costs, but cant seem to get it thru. strange how it works sometimes

sheriffav8r

Well, apparently that VP would cost YOU a lot of money, not her. That's why I've instilled in my wife the idea of never driving my truck. Oh, she's driven it, but usually takes some guys bumper off in the parking lot while trying to park it....

buffalobran

Can you hand prime to get the fuel to those injector lines? (97 dodge diesel, new lift pump and fuel lines...CANNOT get the thing started)

1-5-3-6-2-4

You just exactly described "big injector syndrome"

After a hit at WOT if you snap the throttle shut on a vp truck. Any large injector drains the injection lines be for the vp can refill them when it hits base idle speed. Then shazam you're vapor locked.







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patdaly

You should really be posting in the 12 valve section, but you need to prime the low pressure side, that is accomplished on the 12valve by depressing the priming button multiple times on the lift pump. When you start hearing a sound similar to hissing through your teeth, then you have the low pressure lines filled, and it is returning the fuel through the overflow valve.

Just out of curiosity, why did you change the lift pump?

1-5-3-6-2-4

And did you put the correct lift pump back on. A lift pump for a ve pump engine won't work iirc on a p pump engine.

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buffalobran

oops, of course, my mistake...

I changed the lift pump because there was a leak behind the primer button and i thought that was the reason why i was having serious trouble starting the truck. So I got it off thinking i could just fix it with new parts...but instead decided it was about time to replace it...Parts are a bit cheaper down here also...additionally when i opened it up i found a tiny shard of metal....BUT i replaced it and am still having trouble starting it. SO i thought that the old fuel lines could also be letting air in (which would partly explain a small leak i noticed a few months back right about where the return line comes off of the injector pump)..replaced them just a few days ago...AND STILL HAVING TROUBLE. Primed the air out (through the fuel filter bleed bolt) but still nothing.

Think i'll crack and bleed those injectors to be sure they're getting fuel...then....i don't know.

i appreciate the responce...

and 1-5-3-6-2-4 ... i trusted the fellas at the local Cummins dealer to send my the proper pump for my engine serial number...I have no reason to think that it's the wrong one...but....i'm not sure i could tell ifn' it wasn't the right one, honestly..

1-5-3-6-2-4

Of course I'm not suggesting you ordered the wrong one, but mistakes can happen. Wrong part wrong box, you know.

But crack # 1-2-3 at the injector if theres fuel there it'll fire.

Another source of air intrusion is the fuel heater bowl gaskets and that small 90* hose. You can gut the heater out if the bowl, eliminate 1 of the gaskets. In the big scheme of things its not nessissary. And probably doesn't even work anyways.


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johnh

I've never had that happen to me, even with my stage 3 injectors...................