About HAD it with this air intrusion!!

[Goofyexponent]

I do NOT understand this!!! You would think that with an air intrusion THIS big, you would see fuel running out of the truck SOMEWHERES!

http://www.youtube.com/watch?v=j0rwVVD4jDk&feature=channel_video_title

Someone make sense of that for me? ALL the return line caps, fuel lines and selevtor valve are BONE DRY. It don't take long for it to suck air in...sometimes if I idle for an extended amount of time....it will jump and bounce and miss.

 

[Brianedwardss]

Something worth trying: Get some clear tube and put it in place of the return line that goes from the filter head to the injectors. See if there's air coming from the supply side or the return side.

That's step 1. If that fails to give any results, step 2 is throw a clear tube on the return line coming out of the top-front of the IP and see if there's bubbles coming out of it. If it's indeed air, you'll see if it's air going into the IP or air coming out of the IP. If the IP is good, it should be neither or both

 

[CDX825]

My guess is your leak is between the lift pump and the tanks.

That part of the fuel line is under vacuum so it will pull in air and not leak fuel.

 

[plywood]

Ok, I'll vote.

I would think it would do it all the time if it were pre lift pump.

I'm thinking the air leak is at the filter or the filter-IP line and it's gravity sucking air while turned off, and when you start it it gets a gulp of it.

 

[BigDiesel]

Is your lift pump working. My truck did that when my lift pump (s) died.

 

[Goofyexponent]

Is your lift pump working. My truck did that when my lift pump (s) died.

First thing I checked when the truck started acting up....lift pump is working 100%......although an electric pump MAY be in the works now!!!

Ok, I'll vote.

I would think it would do it all the time if it were pre lift pump.

I'm thinking the air leak is at the filter or the filter-IP line and it's gravity sucking air while turned off, and when you start it it gets a gulp of it.

I checked, rechecked....drank a beer and checked again on this.....no WAY would I find a leak up top!!

My guess is your leak is between the lift pump and the tanks.

That part of the fuel line is under vacuum so it will pull in air and not leak fuel.

You are 100% right! I was thinking about it on the way home....then when I hit a bump it would make the truck go wild....I instantly thought of a splice I put in the steel line where I hadn't looked before.

It would suck air, but would NOT leak fuel becayse it was way up near the top of the engine, under vaccuum!!!

Thanks to all who applied, but the winner is CDX.....no prize, but you have bragging rights, and the right to kick me in the rearend for completely forgetting that splice was even there!!

 

[Cincinnati Guy]

Glad you got it figured out!

 

[gatorman21218]

chris do you have a fuel pressure gauge?

 

[Goofyexponent]

Nope...no fuel pressure gauge. I plan on an electric one in the CCLB I got though.

 

[Kevin 007]

It could be possible that depending on where the arm of the lift pump stops upon shutting you engine down, it could leak at the certain "weak" spot. And you would not notice fuel leaking from it.

I had a 6.2 do a very similar thing once, or wait.....twice!! Two different trucks, and would only do it on rare occasionsl sometimes even after sitting for only half hour. And both times it was the lift pump. Im a BIG fan of stock mechanical pumps on any rig but they can do this. Which in my opinion is better than an electric pump failing instantly without warning when you need the truck the most, or even for survival in these frigid Canadian winters that both you and I are quite familiar with yet likely not very fond of

Good luck and please stay posted!!

 

[BioFarmer93]

Goofy-
I use a cheap SunPro boost gauge as a fuel pressure gauge- it's mounted in a piece of 2" PVC tube with a steep angle cut on the end that's glued (that's right Brad, glued) with a hidden bead of Goop to the hood, ala old Trans Am. It's very sensitive- I can see instantly any change in throttle setting. It doesn't even look too tacky, it's painted to match the hood.. The light is wired in to my fuel pump switch so I always remember to turn the pump off now.

 

[dakotajeep]

Well, after having spent $6000 on maintenance on my 2003 over the last two years, I wish I still had my 94, even with all the issues. Just can't get the wife to buy off on getting an older truck...the $$ on repairs is just not worth it.

Thad

 

[George D.]

Goofy What your decribing sounds exactly like a bad lift pump when the reeds get week they will alow the fule to run back to the tank and it doesn't take much of an airleak to alow this to happen. My truck did the exact same thing a bit after I got back from afghanistan I put a new lift pump in and it fires ringt up even with the return cap leaks I just can't seem to stop.