Okay ,I now have gas

[NWDmax]

Fired up the truck this morning and as I pulled out of the garage the thing dies and won't re-start.

I pump the primer and crack the bleeder on the "Mega" and low an behold a big ole slug of air comes out.

I do this twice till I see fuel only and the truck fires up just fine.

It took 6 to 700 miles of mixed city/highway driving for this to happen so now I'm no longer "gas free".

Blake
:eek:

[56Nomad]

Blake..... This might not be bad!

http://www.fuelpreporator.com/theStory.html

"The most destructive fluid contaminant is air", states Milwaukee School of Engineering
Handbook on Hydraulics. "it causes severe cavitation and can destroy a pump in a matter of
minutes." Caterpillar

[NWDmax]

Thanks 56! I feel better already. smile.gif

[NWDmax]

Now I have to bleed the air every morning before I go to work or the engine fires and dies.

When this happens I have to bleed the Mega filter twice to get all the air out and then it fires right up.

Why did I get two tanks of fuel with minimal air and now a lot of air after only 10 to 20 miles of driving?

Blake :confused:

[chuntag95]

Did you get fuel at your "normal" station? Could you have arrived right after delivery, so more air was mixed in the fuel? Could you have hit a bump and caused a leak in a QD?

[56Nomad]

chuntag95,

Since you have not yet added your Mega filter, and
are attemping to locate an air leak within the system, have
you considered having the dealer try at trouble shooting?
Are you still under warrenty.....

jbplock, a bear, NWDmax, FirstDiesel...... would your
air trapping problems dissappear if you removed the
Mega Filter?

[NWDmax]

56: I'm pretty sure air was present before adding the 2nd filter since the stock offering seems to pass the air along where the Mega filter traps it.

Chris: I always buy my fuel at the same place and use the same pump. I don't know when they fill the tanks but you bring up a good point. Maybe there is a lot more air present in the latest tank of fuel so I'm having to bleed more often.

56: I believe the sympton would dissappear if I removed the Mega filter but the problem would still exist. The mega filter is exposing a shortcoming of the stock fuel system we didn't know was there until now.

[mackin]

How about a show of hands to AIR problems with "STOCK" Dmax ??

1) Hard starting
2) Lose of prime
3) Ruff idle that can't be cured
4) Etc.

Those that are experiencing air now with secondary filtering installed, did you have symptoms prior ??

Now approaching 4th year of production, I can only recall a few incidents of lose of prime associated with filter housing.....

MAC

[56Nomad]

>The mega filter is exposing a shortcoming of the
>stock fuel system we didn't know was there until now.

Now that is what has me scratching my head and I can't
imagine that the diesel engineers could have missed this.
I can't believe that what might be consider a shortcoming
by some, will now be going into the 4th year of production.

[pinehill]

Nomad,

I *can* believe it! Just like the unsolved steering rattle and the poor OEM fuel filtration.

[chuntag95]

56Nomad,
I added my Mega on Saturday. I left the clear hose on until I get my sight glass setup made and installed. I am now trapping the air that was going through my injector pump. I really believe the air is bad for our system. The question I cannot answer is what will the long term effect be? Will it be a problem at 150K, 75K, 300K? It probably will depend on each persons individual system and the quantity of air from that system, fuel, how low you run your tank, etc. There are so many variables that can contribute to this to determine if it's a problem. For some, it will be a killer and for others, never a second of trouble. Which will I be? I know Murphy.

[NWDmax]

Thanks for explaining

[jbplock]

56, Regarding “I can't imagine that the diesel engineers could have missed this”. As a Design Engineer myself, I experience unexpected problems everyday. In fact, if there weren’t problems with the products my company designs and builds I would be out of a job.

My Helms Manual has a detailed procedure for diagnosing the fuel system using clear tubing and vacuum tester. One of the steps says to “install a transparent hose from the fuel injection control module (FICM) outlet to the fuel filter inlet with a vertical loop to observe the incoming fuel for air bubbles. It further says to “Observe the fuel in the transparent hose for air bubbles. If there are no air bubbles of any kind entering the transparent hose with the incoming fuel, the fuel suction system is OK.”
So, I would conclude that the Duramax engineers didn’t intend for air bubbles to be present in the fuel line.

Again , the design of JK’s filter with its long clean side nipple, has unmasked the problem. The fact that the other types of filters being used do not collect air, does not mean they are not passing air.

The fact that there has been a relatively high failure rate for Duramax injectors is more than enough motivation for an anal guy like me keep pursuing this. Besides it’s a lot of fun! :D

[ 04-29-2003: Message edited by: jbplock ]</p>

[hoot]

I was looking at that Fuel Preporator.

I can't decide whether to install it post OEM/Pre Aftermarket, post OEM/Aftermarket or pre OEM/Aftermarket. I figure when I'm done, I won't need an aux tank and I can make Jet A on the side. ;)

[a bear]

Chris; Bill,
Thank you very much. My concern is after 100K. The less free radicals in my system the better. I'm sure the General may also be concerned about 100K but probably in a different way. I keep going back to the pitted (possibly cavitation)worn injector issue that was posted here. IMHO anything spent to help the fuel system is just cheap insurance verses a 6K injector job after the warranty is expired. smile.gif

[ 04-29-2003: Message edited by: a bear ]</p>

[Kennedy]

I've been running mine for over 7k now and have never seen a no start or air related issue. I DO have air n the Mega unit every time I bleed it.

Tip: A LONG screwdriver will allow easy bleeding from above. I also have some thumb screw (wing nutstyle) type of bleeders but access with a hand is limited.


Interseting that Bill pointed out the air location procedure from Helms!

I've also pondered adding some sort of a large chamber extension from the Mega bleeder. Since the groove in the underside of the Mega filter mount "ramps" up to the bleeder, the air will travel to the high spot. A guy could devise a "surge tank" of sorts like the radiator uses, and by operating the primer pump, push this tank full of fuel and snap the bleeder shut. This would extend bleeding intervals and allow a visual check of the air volume trapped...

[NWDmax]

This morning the truck started right up so I'll see how long it goes before I get another"no start" situation.

Blake

[pinehill]

Blake,

What's different now that you no longer have the morning starting problem?

[chuntag95]

Tommy,
I can't agree with you more.

JK,
Interesting thought on the location of a "surge"
tank. I was going post Mega because of the need to change the mega filter. When the system is opened, it will drain back some amount of fuel out of the clean side. Without a bleeder post, I don't know how much will get through, but some air will get trapped. I guess I could have put clear hose from the Mega to the engine to see. I hope my parts get here Thursday so I can install my last line of defense.

Chris

[NWDmax]

Pinehill:Just went out to pull the truck into the garage and it fired and died. It just waited till tonight. Oh well that just saves me from having to do it in the morning! :rolleyes: