Engine/Transmission (1998.5 - 2002) I have new info on 24V LP issues...

[Huff N Puff]

So with the in tank lp replacement, the fuel module and 6 ft of line (up to the fuel filter?) is replaced?











If you have positive pressure @ wot then you can be virtually assured you are supplying enough fuel to the vp44.



If on the other hand you have 0 psi or negative pressure, then you are not, regardless of fuel line size, because as you stated earlier :

The only thing you are assured of is there is pressure in the line. You cannot distinguish if its a solid flow of pressuized fuel, or if its a frothy erated mixture.

 

[Learguy]

H&P, I understand that there is no inlet line. There is a port though, that you said is about 3/4". That should make it about a #8 Fitting (If it was installed). How about the outlet of the pump itself, the line size and type (hard/ soft) from the pump to the fitting that exits the module. The size and type of line of the exit of the module... Are these AN fittings, MS type, compression fittings, all soft lines with barbs and clamps???? What is the physical size of the pump itself? How is it mounted in the tank, i. e. Clamp to a bracket that is attached to the module? There has to be lines to get the fuel out of the tank

 

[whinro]

Dang, this is far too much information for an at best shade tree mechanic. I was hoping to gain some definitive information that I could apply to my own lift-pump problems. I have an 02 QC longbed HO 6spd 4by4 4" BullyDog, STS exhaust manifold,AFE breather system updated with a Pro-Guard 7, Edge EZ, & Pac Brake. Gauges isspro on A pillar fuel pressure uses the isolator principle. 43,000 miles. Ditto all the problems I have read about; erratic and gradual decline of the fuel pressure and finally the engine light and subsequent codes. I wasn't sold on the pump in the tank, particularly after reading Robert Patton's recent article. However, after consulting with a high profile and I think pretty reputable shop in Stockton I went with the dealer installed in-tank pump. Lots of Xmas $ going out lately was certainly a factor as well. It was covered by warranty. They did not replace the VP even though there were 2 codes 1291 and 0216. They ( the mechanic) even said that while there very well could be VP damage they couldn't detect it, but not to worry as it has 5yr 100,000 coverage. OOOkay. Upon start It idles at 91/2 and runs down the road at 5. I immediately went back and talked to the mechanic who gave me the volume pump bit. He said it would not go below 5 lbs under hard acceleration. BS I've seen 3 lbs a couple times. I'm afraid to put my EZ back on the truck. So can some of you out there give me some input on the FASS and the RASP. I have been on the FASS website and talked to a couple of people and it sounds pretty good. The only downside for me with the FASS is that I do end up on and off road and in very muddy conditions and wonder about the location and all the grundge getting thrown on it. I had never heard of the RASP at all. Now, if I do go with one of these the other fear is if the VP give up the ghost and I am still under the window of the warranty will I be denied do to the aftermarket pump? Sorry for the length of this. I don't actually read this stuff very often even though have belonged for as long as have owned my truck from new. This is also my first contribution . Anyway, all info will be greatly appreciated and then I guess it's up to me to, hopefully, make an informed decision. I just want to fix the darn truck as am not one who likes to constantly tinker with it. Whinro

 

[ChrisOlson]

hello I will put my humble opnion here about the 0 psi issue I do agree as far as 0 psi you may still have some flow to the vp or even if you have 3 psi you still have flow but as i understand it the vp needs fuel to cool it and to lubricate it as well it would stand to reason that somewhere some one in DC has a figure that states how much psi flow is required to keep the vp cool I think that the number of 9 to 15 psi is the baseline for this requirement. More flow means better cooling up to a point too much cooling is also bad in many applications I personally keep the psi to the pump at a min of 9 psi if it falls below that or I start having erratic lp pump actions I change the vp I have changed the LP 6 times in 74000 miles I have not switched to a fass or RASP yet because I can always find a lift pump some where and I carry a spare. a relocation to the frame rail will be in my future as soon as possible and maybe even a rasp Still waiting to see what is up there. my humble opnion. have a good day

 

[ChrisOlson]

"I start having erratic lp pump actions I change the vp"

sorry i meant LP have not had my coffee yet

 

[Learguy]

Here is one for all you "Anti-In-Tank" guys, (I am now one of them).



I have the In-Tank pump. Bought truck in 8/20/05 (123,598 miles). Had my LP die on me when I did my first oil/FF change on 9/13/05 (124,649 miles). At that time, had In-Tank LP installed under warranty. They said there was no IP codes at that time.



Went on a 400 mile road trip today (12/18/05). Stop to get fuel, (131,234 miles) Pulled out of truck stop, DEAD PEDAL with CEL. 1 Start cycle, throttle comes back. 3 start cycles, CEL goes out. Happened three different times on trip. Have P1693, 0121, and 0234 as codes on odometer.



Since they have installed this pump, I run 7 to 8 psi @ Idle, 4 to 5 psi @ Cruise, and down to 2 to 3 psi @ WOT.



Luckily, warranty is good until 138,598 miles.



This should be interesting... ... .

 

[PatrickCampbell]

Did I read somewhere about a problem with the pre-screen on the "in" side of the 4601HP ?



If so, can I just take out the screen?



My setup is like this:

#ad

 

[Learguy]

Well, The power train warranty doesn't cover the APPS. Does that sound right? Da**, that's an expensive little bugger!!!!

 

[cyborg]

Since they have installed this pump, I run 7 to 8 psi @ Idle, 4 to 5 psi @ Cruise, and down to 2 to 3 psi @ WOT.

This should be interesting... ... .

I was having similiar problems after the dealer installed the in-tank. First and not to be forgotten: the dealer did a total hack job on the install. They should be embarassed.



My idea is to upgrade the fuel lines and install a LP in its original location.



I did the vulcan 1/2" line kit yesterday. at idle pressure was 8 psi before, now it's 12. Does not drop off to 0 on acceleration either. After shut-down, system holds 5 psi for at least a half hour.



I need to do a little more homework before the LP install.



The vulcan kit is kind of cheezy, but does the job and shows me where I need to go.



Anyone know the thread size for the banjo bolts?

 

[nps]

Anyone know the thread size for the banjo bolts?

IIRC, 12mm x 1. 5. Mine are at home so I can't check now.

 

[PatrickCampbell]

12mm x 1. 5 Metric is right.

http://xj.cdevco.net/auto/fuelsystem/

 

[DRitchie]

fuel pressure and fuel volume are both important butincreasing pressure to achieve it is not the way to fix it if ur running 22psi of fuel pressure ur fuel is going straight to the bypass because the popoff valve on the return line is set at 16-18 psi so if ur excededing that then the vp is just getting the fuel it can catch as its going thru itts just like have a carberator u run 7psi of pressure but run out of fuelon the big end of the track u sont increase the pressure u increase the flow rate . run the f. a. s. s. ull be happy with it

 

[cyborg]

12mm x 1. 5 Metric is right.

http://xj.cdevco.net/auto/fuelsystem/

Nice page Pat. Thanx.

The 1/2" hose with the vulcan kit seems like overkill, but I wonder. With viscosity/waxing issues in winter, there just might be an advantage.



DRitchie: I have no idea what you said.

 

[scotty1]

Here is a link to the numbers from an Edelbrock pump.

Its from Essex and I have this pump.



As you can see... less pressure, more flow/volume.

Pressure equates to resistance. However, one must have a balance for the combinations out there with the VP-44 trucks and whatever power mods they have as well as the CP3's on the 3rd gens.

Lots a variables.



http://www.dieseltruckresource.com/pics/showphoto.php?photo=9508&password=&sort=1&cat=500&page=3



Scotty

 

[Fishin Guide]

fuel pressure and fuel volume are both important butincreasing pressure to achieve it is not the way to fix it if ur running 22psi of fuel pressure ur fuel is going straight to the bypass because the popoff valve on the return line is set at 16-18 psi so if ur excededing that then the vp is just getting the fuel it can catch as its going thru itts just like have a carberator u run 7psi of pressure but run out of fuelon the big end of the track u sont increase the pressure u increase the flow rate . run the f. a. s. s. ull be happy with it

Was this written with one of those dialectizers? Seems to be working.



I want at least enough pressure to keep the bypass open in my VP. I want the fuel to pass through it, and cool the internals. Fuel is bypassed through the pump at lower presssures as well, but not as much. Is it enough? I don't know. That's why I am on the high side of that measurement.



Also, I have tried to lower my fuel presssure by removing the overflow valve all together. It didn't help. Seems there is some internal resistance to flow within the VP.



More pressure is good to a point I am sure. DD has been putting 12V lift pumps in with cams behind the VP for several years and many of those run really big pressures. I have yet to hear of a failure due to high pressure.



Dave

 

[Bobalos]

after my 2nd carter pump failed I yanked one of my Mallory 140 pumps out of the cabinet & went to town with some AN fittings & Line. it runs ~18 Lbs @ Idle & comes just below 15 Lbs @ 70 MPH. been in for 10 months now & >45K miles (200+ Miles/day commute)



http://store.summitracing.com/defau...eywordSearch&DDS=1&N=115&target=egnsearch.asp



Mallory is not so happy about it, they said that the sulfur in the fuel will "eat it up". I blueprinted the pump B4 I stuck it in, when it dies I will swap it out with another one I have on the shelf & go back through it & figure out the failure mode. these are Old Nitrous parts I had lying around, when I stepped up. I would imagine that there will likely be a clearance issue (not gasket related). if thats the case, I will buy another one, have it hard anodised & see if that does not extend the life. So far so good. not a hickup.



IMO, elect fuel pumps are for pushing not pulling.



Bob

 

[WyattEarp]

well knock on wood but so far i have only had the lp go out one time, that was less than a month after it leaving the lot, now what they did as far as a fix other than a new one i have no idea. . I do know that i keep a steady flow of powerservice in my fuel regardless of weather, winter or spring, and i keep the fuel filter changed at every fuel change, this last time i didn't and wednesday morning my dad said it was wanting to lunge, at first i thought dam, transmission. then i told him i needed to drive it just to check things out since he has been driving it and isn't exactly up to par on whats the ups and downs of having this rig under his foot... from idle 60 no problems, 62mph i noticed what seemed to be a miss of sorts, i got into it and no puff of smoke at all from the exhaust, my first impression after the transmission thought was injector, that morning it was 11 degrees out and dad had put 4 tanks through it without treating the diesel. before i left that morning to drive it i dumped in a generous amount of PService. after getting back i changed out the fuel filter, while coming back from town i got into it up to 80mph and nothing, so im guessing it was alittle bit of gelled fuel, told dad that the powerservice was in the basement and to treat at least every other tank before he fueled up, had the truck since dec. 99 and thats the first time it had done it, i think i figured it out though.

As for the fuel pressure, i have no guages(okay i know im going to get it now LOL) but relying on a station to switch to winter blend isn't the best, i told dad there had to be either water in that stations fuel or they have not switched to winter blend.

If mine goes out i do hope they put the upgraded pump in, the only down side to the intake install is if it goes out and your tank is full, the only recourse is the garage or dealer, i don't keep 34 one gal. jugs on hand to dump the fuel in...

 

[cyborg]

Maybe the mechanical pumps don't "over supply" because they are dependent on engine RPM. Just a theory.



I found some 3/8 "marine fuel hose". Says something about being alcohol resistant. Has a durable looking grey outer sheath.



Maybe these super pumps (FASS, RASP, BLAST) are just forcing an adequate supply past a restrictive system? That line between the filter and the VP is only about the size of a gerbils pecker. I imagine opening that up is a big help by itself. .

 

[steved]

Maybe the mechanical pumps don't "over supply" because they are dependent on engine RPM. Just a theory.



I found some 3/8 "marine fuel hose". Says something about being alcohol resistant. Has a durable looking grey outer sheath.



Maybe these super pumps (FASS, RASP, BLAST) are just forcing an adequate supply past a restrictive system? That line between the filter and the VP is only about the size of a gerbils pecker. I imagine opening that up is a big help by itself. .

The FASS and RASP use 3/8" or 1/2" line from the tank inlet to the injection pump... the restrictive factory lines/fittings are all but replaced... with the FASS "system" (not just the FASS II pump), the most restrictive part is the pickup tube in the tank.



steved

 

[WyattEarp]

I know he didn't say Gerbil pecker LMAO. . think we all needed a good chuckle. . I agree the lines being smaller and trying to force more fuel with the same line might be some of the problem. no matter what pressure you can only force so much fuel through any certain size line.