Engine/Transmission (1998.5 - 2002) FINALLY!!!! Some one puts an end to Carter!!

[wlowe]

The excess fuel bypass valve I am talking about is the AN-6 bypass valve you put into the fuel system just before the VP44 to dump the excess fuel back to the tank. My observation is that an AN-6 (3/8") line (back to the tank) can handle a Walbro 392 AND a RASP at the same time without apparent difficulty.



-- Not the VP44's bypass valve mounted in the body of the VP44 which only takes care of the VP44 -- and has NOTHING to do with replumbing the fuel system (ie adding the Walbro lp). I want to be absolutely clear on that.



Bob Weis

No misunderstanding, I wasn't confused about which bypass you were talking about. Correct me if I am wrong, but I was under the impression that your bypass incorporates a Kinsler Jetcan check valve to regulate the pressure. This is why I was surprised that the Kinsler would regulate an increase in pressure without re-shimming.

 

[PRout]

Nice setups!

I was a little concerned about losing prime by using a regulated bypass mounted at the VP44, so I ended up using a manually operated valve to purge air instead (well, also that return line on mine flows to the aux tank so it will also allow for emptying of the main tank). I'm glad to "not" hear of losing prime being a problem.

I may have to raise the output of the fass to say 18-20 psi and swap out the manual valve for a regulator as you guys are doing and setting that regulator for as close to 13. 5 as possible. 'Course it would have to be re-routed back to the main tank. Hmmm. . Could keep the manual. .

Thanks for following up on this one, it is very informative, and... here we go again!! Time to get covered in fuel because it'll be the excuse I've been (not) looking for to drop the tank (again) and replace that derned disintegrating fuel float. . ughhh! Gotta love it.

 

[rweis]

wlowe -



Well, I use a identical PAIR of Kinsler JetCans (set exactely the same) which might be the reason. I use a pair as redundancy, but also I was having a time getting exactely identical results with only one JetCan.



I determined that it was because the spring travel was not quite linear, so to reduce the spring travel I put in a pair of them so each one could take some of the pressure regulation and have not as much spring travel. The concept of a pair of them holding a more exact psi with only the RASP was correct.



Now that there is also the Walbro pump, the paired concept is still holding true. However, after I split the fuel path and go through each one of them in parallel, I rejoin the fuel path to a single AN-6 line. I was some what surprised that the AN-6 single line could handle both the RASP and Walbro at the same time, and that was the key to the post.



Bob Weis

 

[rweis]

"excuse I've been (not) looking for to drop the tank (again)"



On a lighter note- I installed my Tempo fuel level gauge mechanism BACKWARDS months ago on the first try, then I reinstalled it correctly (swing forward) and have been runing that for 6 months. Because I had "extra" mounting holes from the backward install I had some "seepage". I bought an extra tank from one of the TDR members and last 2 days I have been transfering the CORRECT install to the new tank. Well, "got er done" this afternoon and when I was cleaning up the tools I "found" the FLOAT I WAS SUPPOSE TO INSTALL ON THE gauge mechanism BEFORE I REMOUNTED the tank. :{ :{ :{ :{ . Guess what I am going to be doing in the morning?



Bob Weis

 

[Gary - K7GLD]

"Old-timer's disease!" :-laf:-laf:-laf

 

[rweis]

Yeah - CRS (Can't remember sh. . )



Bob Weis

 

[PRout]

Ohhhh man, we hate it when that happens! And I thought I was the only one that does stuff like that. . :{ Awww, Just think of how GOOOOD it's gonna be.

 

[MRyan]

Part No: E7153









Description Value

Gallons Per Hour 70-80

PSI Shut Off 15-18

Type Rollervane

Volts 12















close window

 

[MAV1]

relocation adapter for the Airtex

Airtex Pump Adapter

Previous to now, I was having a local machinist turn and thread adapters for me on an as needed basis. Since each one was basically a one off, the cost was higher than the adapter now available from Vulcan Performance. From now on, I will be using Vulcan's adapter and will be keeping several on hand for utilizing the relocation kit for Airtex installs on the frame rail.

Thanks Eric

MAV1

 

[BK]

MAV1, ah , nice.

I have the smaller Volcan relocation kit from Genos. I bought 4 campaign pumps.

A few months ago a buddy of mine and I installed the kit and one of the campaign pumps. Goes real quick with two on the job.



Been great since, solid 16-7psi at idle and 13 at WOT. Keep my fingers crossed I'll get another 25K out of this LP. Then 3 to go, At ~25K each @ $60 each, I'll be set for the next 15 years. Mine's a 99 with 60K miles on it.



'Most' of this thread has been of great intereset since I don't see a need for me to go with one of the aftermarket big buck systems with my stock engine.

 

[sshelly]

Unless of course you just love changing out the lift pump every 25k. I was done with that crap. Decided I'd fix the problem right and got a great deal on an Airdog .

 

[JR2]

Airtex Pump Adapter



Previous to now, I was having a local machinist turn and thread adapters for me on an as needed basis. Since each one was basically a one off, the cost was higher than the adapter now available from Vulcan Performance. From now on, I will be using Vulcan's adapter and will be keeping several on hand for utilizing the relocation kit for Airtex installs on the frame rail.



Thanks Eric



MAV1

What do you do on the other end of the pump?? I have stainless steel AN6 lines from the pump to the VP44 with my lift pump on the frame. I have Webber carb adapters that screw into the lift pump so I can hook up the AN lines. It looks like the airtex pump only has the ability to have a hose slid on it?? But it looks like that end might be removable... . any help?

 

[rweis]

Im not too familiar with the rasp, but it seems like the walbro would make a nice backup pump for the rasp, or any primary lift pump for that matter. Im guessing the backup would be the initial priming pump before the rasp gets "spooled up" and takes over.



This brings up a question. . Is there some type of check valve or some way of holding prime for the rasp when the truck sits not running, or is this even an issue? Would not want to be introducing air in the system everytime the truck sits for a while.



...

I am currently testing running the RASP ONLY. No Walbro on startup. It appears that the RASP pressures bleed down to about 6# and hold there. On initial key on you can see the 6# steady, then as you crank the starter the 6# starts rising in the next second to about 12#. In the #2 second of engine start and the engine has probably rotated xx times the RASP is up to normal pressure and the engine is starting.



My thinking is: There is a small cavity under the PSG where fuel enters before it goes on throughout the VP44. On bleed down over night this cavity remains full with miminal pressure at the VP44 inlet to this same cavity.



When you begin the engine rotation for start the RASP starts pumping again. The ratio of the RASP crankshaft pulley to the RASP pump shaft pulley is 2. 5:1 so the engine has to rotate 2. 5 times before you get the first 1 RASP shaft rotation and fuel pressurization increases. The subsequent several rotations of the crankshaft brings up the RASP pressures to your bypass settings as the VP44 starts to rotate (the VP44 rotates at the camshaft speed or 1/2 of the crankshaft speed). I would bet the first couple of injections from the VP44 do not culminate in combustion (someone correct me if I am wrong), and it is not until the 6th or so injection (my guess) that combustion occurs and by then the RASP is fully up to pressure.



I have my Walbro on a seperate switch and see no difference in start if I turn on the Walbro (for full lp pressure) prior to starter rotation or not.



The pressure prior to engine starter rotation also tells me my fuel system does not bleed down to zero overnight. I will experiment with it some when I do not start it for a couple of days and report that information back as those time periods occur.



It could be a very truck dependent thing based on the integrity of YOUR fuel system.



Bob Weis

 

[rweis]

What do you do on the other end of the pump?? I have stainless steel AN6 lines from the pump to the VP44 with my lift pump on the frame. I have Webber carb adapters that screw into the lift pump so I can hook up the AN lines. It looks like the airtex pump only has the ability to have a hose slid on it?? But it looks like that end might be removable... . any help?

I got my Walbro with both ends with AN-6 adapters. Since the AirTex is the same physical frame I would think you could do the same. Search around the Walbro sites for AN-6 adapters.



MAV1 "Previous to now, I was having a local machinist turn and thread adapters for me on an as needed basis. Since each one was basically a one off, the cost was higher than the adapter now available from Vulcan Performance. From now on, I will be using Vulcan's adapter and will be keeping several on hand for utilizing the relocation kit for Airtex installs on the frame rail. ".



I had to be sure the "install kit" included the copper sealing washer for the AN-6 fitting for each end of the pump frame.



Bob Weis

 

[MAV1]

inlet adapter

What do you do on the other end of the pump?? I have stainless steel AN6 lines from the pump to the VP44 with my lift pump on the frame. I have Webber carb adapters that screw into the lift pump so I can hook up the AN lines. It looks like the airtex pump only has the ability to have a hose slid on it?? But it looks like that end might be removable... . any help?

The inlet fitting is removable, it simply threads on with straight threads, not pipe threads and seals with an internal o-ring and thread sealant ( I used Permatex pn54540).
When I took the Airtex pump and the associated AN fittings to my machinist for adapters, he handled the inlet as follows; after removing it from the pump, he milled the inlet tube off while simultaneously milling a recess in the inlet end of the fitting. He then turned a brass cylinder, a coupler of sorts, of matching diameter, drilled, tapped and threaded one end, and silver soldered it to the brass fitting, inside the recess previously milled. The AN fitting then screws into the brass coupler. In the event that I ever have to replace the pump, which I doubt, especially since it is a Walbro Oo. , I'll simply remove the modified inlet fitting and transfer it to the new pump.


As a side note, for those that do not wish to modify the inlet fitting for a relocation kit, instead of installing the relocation kit supplied pushlock swivel connector on one end of the 3/8" fuel line supplied to go between the oe steel fuel line and the pump, just slide the 3/8" fuel line onto the fitting up to the collar and hose clamp it in place same as installing the other end to the steel fuel line cut to install relocation kit.

JR2, hope this helps and thanks for the support you voiced.
Feel free to send me a pm if you like and I will provide a phone number if you'd like additional help.

 

[JR2]

Are the inlet threads a standard size so maybe I could just buy some adapters and make something work?? Either that our I could just dump the bling SS hose and go to normal fuel line.

Thanks for your help. . the project is not "on my list".

John

 

[BHitt]

I am working on my third LP for my truck a 99 2500 and finally installed a BD asist pump on the frame also a pressure gauge at the filter. The big prob lem seems to be the relief valve. Why Cummins and Dodge have not been sued over this stuff is beyond me!!

 

[PRout]

Agreed to the above post. . Having a loss of power at the wrong moment is only a matter of odds and with as many that fail, is a real safety issue. But it's water under the bridge for DC at this point.

It appears that the RASP pressures bleed down to about 6# and hold there.

My thinking is: There is a small cavity under the PSG where fuel enters before it goes on throughout the VP44. On bleed down over night this cavity remains full with miminal pressure at the VP44 inlet to this same cavity.

It could be a very truck dependent thing based on the integrity of YOUR fuel system.

Bob Weis

Interesting, sounds like a pretty air tight system then. Thanks for the info. . Its too bad they eliminated the cam lobe for the mechanical pump. That would mean less noise interference for the CB'ers & hams too.

 

[rweis]

Been a little over a week now, RASP still cranking right up WITHOUT any electrical pump pressure prior to engine start. Truck sat without starting for the weekend (5:30pm 1/4 - 07:30am 1/7) cranked just fine 1/7.



At this rate the Walbro should last decades , but it is there if needed.



Bob Weis

 

[LarryG]

I'm on my 4th lift pump in 99,500 miles, all dealer installed, second in-tank pump in just over 1 year (interpret beyond 12 month warrantee). I drive like an old man because at $3. 37/gal, I drive for mileage. I seldom let the tank get below 1/2 full, except for occaisionally I empty it down more to get a greater percentage of fresh fuel. Bought this truck new in '02 and it has been the least reliable piece of equipment I ever invested in. My wife hesitates to go with me fearing we will end up by the side of the road. This site is more than a social network - Dodges should come with a lifetime membership in TDR as standard equipment, something like On-Star in GM!