Engine/Transmission (1998.5 - 2002) Vulcan Draw Straw

[NoSeeUm]

I finally got mine in yesterday. Noticeable improvement, but I also did a big line installation. Here are some initial results.



Idle = 15 psi ----> 16 psi

Hi-Way = 13 psi ----> 15 psi

WOT = 3 psi ---->11 psi



My installation got complicated because I wanted to have two pumps on board. In my case all the failures and to many years in the Power Plants (Navy) so the "Installed Spare" concept bolts right up in my brain. The primary is a (going to be - not quite done yet) Walbro GS391 in conjunction with a Mallory 4307M regulator. The back up is the OEM Carter.



At this time I only have the Carter working. I still need to install the modified wiring to support the Walbro. The only down side I found so far is that the Carter is a very noisy pump. When it is hard mounted to the frame and sits right under the drivers seat you hear it all the time. I need to sound mount the thing in rubber grommets.



Here is a picture of the Draw Straw installed in the tank:

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The Walbro and the regulator are not tubed in yet in this picture. I have completed the tubing, if any one is interested I will take another snapshot. The blue thing is an inline fuel filter. Here is a picture of my new mess:

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FWIW my upper (return) screen was pretty dirty. From what I could tell this screen has no effect on the draw tube suction and is removed when the Draw Straw is installed. Here is the picture:

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Jim

 

[BTowler]

I am guessing the tank has to be dropped for this install? My sending unit is sticking, ran out of diesel last week when the gauge read over 1/4 tank! It took 34. 2 gallons to fill so I don't think it is a broken pick-up. Might as well kill two birds with one stone.

 

[DMannon]

Jim,



What's the black pump-looking thing with the black and orange hose attached? Is that the Mallory regulator?



BTW, nice install...



BTowler, once you're down to 1/4 tank, dropping it is no big deal. I did by myself, and I'm an old fart...



Here's a post by AlphaCowboy, who had tank and fuel guage problems:http://turbodieselregister.com/forums/showthread.php?t=162740

 

[PRout]

Time to drop the tank and install a sump box.

This would be my next mod to the fuel system also. Since installing a 1/2" tube to the bottom of the tank, I also see it sucks air sometimes under 1/4 full.

Have been thinking of how to accomplish adding some kind of sump box as well. Maybe some kind of an intermediate tank setup, but dont want to make a simple system more complicated.

Also, noticed the last time the tank was down, the level "float" itself is deteriorating and doesnt look like its going to last much longer. Wish someone made a better float. .

 

[lsenus]

NoSeeUm,

That WOT fuel presure seems a little low. When I installed my draw straw, I guess I left it a little long, and it was actually touching the intank screen. I had good presures at idle, but could also draw it very low under acceleration. Once I trimmed the pickup tube so it sat about 3/16 above the screen, no more problems. 14. 2 idle, 13. 8 at 55mph, 13. 4 at 70 mph 2500 rpms, and 13. 2 with the trailer loaded going up hill. Double check the clearance between the pickup tube end and the filter screen.

 

[Jeff Knight]

I have the smaller filter from Vulcan. I cut all the screen out of the puck that snaps on the bottom of the module.

 

[NoSeeUm]

I am guessing the tank has to be dropped for this install? My sending unit is sticking, ran out of diesel last week when the gauge read over 1/4 tank! It took 34. 2 gallons to fill so I don't think it is a broken pick-up. Might as well kill two birds with one stone.

For some reason I detest dropping tanks. This one would be rather mild, but I still lifted the bed off. Keep in mind I have access to a gantry crane. The pick-up float sender on my truck is on a plastic slide, not one of the ones that bolt on.

What's the black pump-looking thing with the black and orange hose attached? Is that the Mallory regulator?

Yes, I already had the Mallory so I used it. In the picture only the bypass is connected.

That WOT fuel presure seems a little low. When I installed my draw straw, I guess I left it a little long, and it was actually touching the intank screen. I had good presures at idle, but could also draw it very low under acceleration. Once I trimmed the pickup tube so it sat about 3/16 above the screen, no more problems. 14. 2 idle, 13. 8 at 55mph, 13. 4 at 70 mph 2500 rpms, and 13. 2 with the trailer loaded going up hill. Double check the clearance between the pickup tube end and the filter screen.

Hopefully I trimmed my Draw Straw 3/16 of an inch above the bottom screen at about a 30 degree angle. That was my intention anyways.



Actually now that I have goofed with it more my pressure stays above 12 psi at WOT. Before I put in the bigger injectors I could pull the pressure down below 7psi, after the injectors 3 psi or below. I mean scary low. So this is a huge improvement for me.



Its just SOP, but(t) it actually feels like I am fueling with the TST on levels 6-9, before there did not really seem much difference in any level above 5. The engine tried but just seemed to make more noise. Today, although accidently, was the first time I officially lit a rear tire off giving a guy a ride in my truck. Actually twice, most of 3rd and a little in 4th. Thats how fixated I was watching the dang pressure gauge.

I have the smaller filter from Vulcan. I cut all the screen out of the puck that snaps on the bottom of the module.

I really thought I would do that also, until I got to looking at the module. On my module the fuel enters from a 1/2 inch wide slot in the side. This is true as long as there was more fuel in the tank than the level of the puck. Once the level went below that, it looked to me like fuel could only enter from the bottom screen. Hope I was right, because I left the bottom screen in place.



Jim

 

[Froadin]

Hmm, good info. I just ordered my draw straw today. I also ordered the large line kit, so I will install it all at once, and run 1/2" line directly from the module to the pumps, etc.



I will be taking the bed off to do mine. I need to straighten out the bed in a few places, so I will get a lot of things done at once.

 

[Froadin]

Ok, pulled my sender out today and found out my float was falling apart as well.



Is this a Dodge only part? And does anyone have the part number? I have an hour plus drive to any dodge dealer, so I want to make SURE before I drive there!

 

[rweis]

In the "old days" fuel floats were made of this brass flat sheet material in like a cylinder shape. As I recall the parts were soldered together with a lead solder. Were those floats better than what we have now? If so, how hard do you think it would be make a replica in brass?, and where would you look for the very very thin brass material to make one?



The "new version" might be easier to manufacturer or easier to mount, but may not hold up as well.



Bob Weis

 

[BTowler]

Bob,

You can find the brass at most hobby stores or at a jewelers supply. I don't think it is just regular lead solder, I think you would at least have to use a low temp silver bearing soft solder.

 

[rweis]

Do you think it would make a "better" float? low mass, good weight to displacement ratio.



I need a little more input as to the solder and a source.



We manufacture most everything else in this "fuel" system, might as well do this as well and be sure of the quality: "hand made in the USA".



Bob Weis

 

[Froadin]

You find a way to accurately make a replacement that is good quality, and I think you will sell a FEW of them!

 

[DavidC]

In the "old days" fuel floats were made of this brass flat sheet material in like a cylinder shape. As I recall the parts were soldered together with a lead solder. Were those floats better than what we have now? If so, how hard do you think it would be make a replica in brass?, and where would you look for the very very thin brass material to make one?



The "new version" might be easier to manufacturer or easier to mount, but may not hold up as well.



Bob Weis

The brass float in my 70 roadrunner is 36 years old



Dave

 

[BTowler]

Bob, pm'd the info to you.

 

[BTowler]

Does anybody have the rough dimensions for the float? I am going to work up a prototype brass float.

 

[DavidC]

Does anybody have the rough dimensions for the float? I am going to work up a prototype brass float.

I would think it would need a new design. The roadrunner float is approx. 1" in diameter. Looks like a miniature 55 gallon drum. On one end it has an inverted seam that holds the float in the potentiomer arm which has a round section, a press fit. My idea would be to use this system with a rod that would attach the the existing Dodge float rod. You would probably not want to build a brass float to mimic Dodges idea as it is a loose fit and probably would eventually wear thru the brass.



Dave

 

[Froadin]

Ok, just finished installing my pusher pump big line kit AND draw straw from Vulcan. I got extra line from him so I ran 1/2" line from the draw straw to the injector pump! I have the stock LP on the frame and the 7psi carter in the stock spot.



I feel that fuel line is kind of like battery cables, you almost cannot have overkill!

No idea on pressure, as I am missing a fitting for my gauge But I will see what I have in the next couple days.

I have to put the bed back on, but I did start it and let it run.

Now I feel comfortable with my fuel, I can tap my pump wire again!!!

 

[GiesJ]

Now I feel comfortable with my fuel, I can tap my pump wire again!!!

I'm looking for a way not to be gunshy on doing the same thing. I'm on my 4th VP 44... Let us know how you fee once the wire has been tapped. Good luck!

 

[NoSeeUm]

Call me crazy, but my cold engine idle lope has disappeared. I noticed it gone after I finishing doing all the fuel supply work.



No clue --> crossing my fingers.



Jim