Attn: Big Blue Possible CAT Fix

[Victory Red]

Can't go into much detail now but I've fixed my start/stall issues. Not sure if this'll work for you(or even if you're still having problems), but the fix is as simple as repositioning the filter head.

Your mount is different than mine but you should be able to accomplish it as well.
Plain and simple, add a down angle to the the outlet side of the filter head(the side with the bleeder screw) around the thickness of a 1/4" hardened washer.

Haven't quite figured out the logistics of this yet, but for whatever reason it stopped my stalls. I still get an occasional rumble(fuel starvation) but never enough to stall out the motor.

I have a few theories for my case(hopefully yours as well), but I'm not even sure if you're still 'suffering'.

[imported_]

Its funny you posted this today as I now have my cat filter at about a 10 degree angle to "pass gas". Modified yesterday, as the temperature rise to 30+. Previous to this I haven't had a stall at all when the temperature out side is below 25 C. above that it is random and dependant on fuel level in the tank. After the angle mount (same thing you accomplish with the spacer) I don't get the slight rumble/hesitation any more on start up. I "hope" the bosch pump design allows for this passing of gas to the return line before it hits the injectors. As stated previously, I don't think we are causing the air, just catching it, so I hope my truck can deal with it.

Thanks for keeping me informed of your progress, I'll try and do the same.

[Victory Red]

I'm not exactly sure where the air goes also, but I'm glad I don't have to prime anymore except for filter changes.

Anyhow it's either the filter head design or a goof up on our part. Than again if you tilted the bleeder side 'down' as I did, it tends to lead to a design issue.

Also I think the stock system has air as well, it just lets it go on it's merry way though.

I found my spacer trick by accident. Intially on setup I added a small(2 mm) spacer so that I could easily fit a socket in to open the bleeder. When playing I decided to remove it and my problem got worse. I had to prime almost everytime my truck sat 4hrs plus. So I made a new one at work on our mill and made it a little thicker. Low and behold it's actually better than before.

Not sure if there'll be any long term ill effects except for maybe a little 'unused spot' because of the tilt.

I've got a trip to Plymouth MA at the end of this month. It'll be a good 2500+ round trip for me and the family. I'll have to see how well she behaves. I'll have 5k on the system at that time. I've also averaged 19.5+mpg for the last 4 fillups. I hope to break the elusive 20mpg barrier on my trip.

[ 07-13-2003, 11:35 AM: Message edited by: Victory Red ]

[Gbenzx01]

VictoryRed,
Thanx for sharing your new found discovery that gravity cannot pull air DOWN!
Our 3 filter system with the cat & Stanadyne pump/filter/water getter running full time is working wonders & will bypass when set at 50% on the fly just by flipping off the switch or when the filter clogs.
But when we off the switch & goto full bypass for the suction & left for hour or more we still hear the little rumble after 5 - 10 seconds.
We will tilt the filter first chance, Thanx.
No not done yet, if it didn't do it before the install must be something we did? Sure was, we lowered the flow level of the fuel! Get the straw out fill it up, hold it level & begin to tilt it. Now we know do we not?
The chk valve in the bosch can hold fluid until it shuts down, right? But when it shuts down the air in the filter simply swaps places with the fuel that fell straight down!
The air created cavity in the filter was caused by the suction force of course & now becomes an air lock.
All together now, will all the Reds & Yellows please lean forward & take a deep breath!
VictoryRed I could tell the way you talked before you even got the filter you would find a way & you did just that. Thanx again, you have made my day!

Thnx, Gben

[ 07-13-2003, 09:18 PM: Message edited by: Gbenzx01 ]

[Victory Red]

Gbenzx,

I hope the fix works for your setup as well.

I was determined to find a fix and have it simple. It's one thing to spend a few hours and $125 on a secondary setup. When you begin to have to add part after part to continue to fix your fixes well, it just becomes too much hassle, too costly, and too much extra maintenance with the chance of additional component failure.

I'm in belief that I've improved the stock system in capabilities. I also believe an inline check valve will accomplish similiar results.

The one mistake I made in my setup is was not putting in a way to take easy samples. Nor is my installation as pretty as the Mega. It's well designed, looks good, and easy to bleed.

Thanks for the kudos on the 'fix' but the real thanks go to everyone. Guys like JK, Greg and George for pointing out that our systems aren't quite up to snuff and offering kits. Hoot and Nomad for trying Racors. Cat users like Big Blue that privately emailed me to help with part assembly. The various dealers for supporting this forum and offering good deals on parts. All the DP members for there hard hours of work and research.

This is a community effort to improve upon what the factory offers us. My next task is to do an actual fuel sample. I may have to enlist the help of someone to walk me through it to make sure I get a good sample.

Anyhow now since it seems like I've gotten beyond my first real mod, what's next for truck???? :rolleyes:

[Gbenzx01]

VictoryRed,
Right on, & probly take DP for granted sometimes but aside from couple comedians from such foreign countries as ca,al,pa&ct(need some tho)where else could one find such know how in one place?
Since my edit didn't work out rite, need to patch couple things in post above.
1st I would guess most folks but me knew very well that the chk valve in the bosch does not hold the fuel up when the Dmax is running. Did that make sense, because with air in the post oem filter it won't hold the fuel up after shutdown either. Ok, with the Dmax running the sucking sound at the bosch holds the fuel UP, period?
Do believe tho ya rite abt chk valve inline at out port on the post oems & looks like JK is upto something good with this scheme.
Good friend says today that coming out & down instead of up on the 90 fitting should accomplish the airlock as well. Maybe? But don't look like enough room todo this?
I'm thimks tho that when we move the cat to the oem position (more level with Bosch pump) air will be gone too? Won't do this yet tho until something is better resolved abt eng vibration skewing the filtration at the oem position???

Thanx, Gben

[Victory Red]

Gbenzx,

As your friend suggested I considered moving the position of the 90's as well. Problem with that is the looping of the hose, plus since I already cut the lines to length, i'd have to replace to try it.

I do believe that the check valve will work as well, I'm sure John will chime in after he's completed his research. I searched for one for a while, but came up empty for an external fuel capable inline check. So off I went looking at other options.

Ideally yes, it would be best to get the secondary as close to the OEM as possible. If I assume correctly, the longer the lines the more vacuum you need/is created to pass the fuel through the system. I doubt the increase is very high, but maybe just enough to offset the system to cause the prime loss. Heat and vacuum will also cause the air in our fuel to seperate from the liquid.

All in all it seems to be a large combination of things that cause this situation.

Bottom line I wanted a cheap/easy/low maintenance fix. I think I found it. tongue.gif