Hey guys I need some advise(help!) again. Last night while getting off the freeway I stood on the throttle for a second and as soon as I let off the truck died. I coasted to the shoulder and tryed starting it again but nothing. I'm thinking a died injector pump again. The batteries had plenty of juice. I had it towed home and checked codes using the key trick and the code finder but no codes came up. The lift pump is still working and at the time it died my fuel pressure read about 12lbs. I've installed a low pressure light in the dash and it never came on while the truck was running.
I have less than 5000 mile on my vp44. 7000 on my lift pump. I'm pertty edited by admin at myself because I didn't want to spend anymore money on it anytime soon. Hopfully its a loose wire or blow fuse....Hopefully
Any ideas or thoughts would be appreciated. Thanks guys

 

I had a buddy's truck that would do that. die, and you could crank it till the batteries ran down and it wouldn't start, BUT you could pull it, or push it, pop the clutch and it would fire right up. then you could shut the key off, and it would start right back up , no problem. If I hadn't seen it twice, I would have had to call BS on this, but it happened several time on him. P.S. a couple months later we put him on a new IP, and it hasn't do it sense.

 

You might have vapor locked the pump. I've heard of them doing that. Might try cracking some lines and trying to crank it over then.

 

Vapor lock? What causes that? When I get home I'll crack the lines and see if fuel comes out.

 

Normally it's from being at WOT and then suddenly backing off. The injection pump momentarily sucks air or the fuel in the lines suddenly vaporize and you air lock the engine.

 

How do you cure vapor lock from happening? New fuel draw straw?

 

Don't know of anyway to cure it. Best way I've heard to control it is either ease off the throttle after going WOT or feather it after you let off.

 

Thanks. So when you vapor lock a IP it dosen't mean its died right? Either way I'll get it fixed.

 

no the vp doesn't die when you vapor lock it---no known cure except your right foot---loosen #3 & #4 & #5 injector line nuts and crank over till you get fuel coming out of them, then tighten them back up--crank over a 2-4 times and it should start---that's why I always have a 19mm wrench in the door pocket---chris

 

i thought vapor lock was when the fuel turns from a (liquid state) into a (gas state) due to heat?
Ive seen some race/gas cars get vapor lock that can usually be cooled by relocating the pump to a cooler location and also making the pump lower then the sump on the tank. Im still learning about diesels though...

 

They're describing a Fuel Starvation condition and calling it Vapor Lock.

If the fuel pickup in the tank gets uncovered, or you pull more fuel than your Lift pump can provide, you loose your fuel supply to the Injection pump and presto.......you're sitting on the side of the road hoping you have a wrench with you so you can bleed the injector lines.

 

Unless his fuel level was low in the tank, fuel starvation would not be a likely cause since he is reporting 12 psi of pressure when the truck stalled.
-P

 

it doesn't matter how much pressure you have from your lift pump and it doesn't matter how much fuel you have in your tank although when it's low it may may happen more often, but that's not been proven--it will starve it instantly--I've done it many times --with low tank, full tank, 1/2 tank and with 19psi at the VP---what I think happens is when you are hammering it and then lift up you get a suction effect from the the combustion chamber and it pulls the fuel out of the injector, crossover's and lines before the VP can catch up because the fuel shut down is faster than the engine reaction---chris

 

I was unable to check the truck last night but I'll bleed the lines after work. The truck has alittle over a 1/4 tank right now. If all I need is a 19mm wrench that would be great!

 

Thanks guys for all your help! I just crack a few injector lines, turned the truck over several times, retightened the lines and the truck started. I still don't understand how vapor lock happens, how it can be prevented or if its even called Vapor Lock. I guess I'll just be a little easier on that skinny pedal.
Anyways if you guys were here I'd buy drinks all around!! I love my truck again.