TESTING REVEALS - "PRIME-LOC" NOT TO BLAME FOR INJECTION PUMP FAILURES!!!

[illflem]

Just from my own experience working on hydraulic and water systems
when the pressure (psi) drops,so does the volume,I don't know how
Prime-Loc is coming up with their numbers.

 

[Berserker]

But wouldn't you agree that bringing up the pressure won't necessarily increase volume? remember, we have changed the dynamics with different line sizes, distances, obstructions and filters.

Is the lift pump just pumping volume or is it a pressure pump? It looks to me like it's only pumping volume. Of course it could bog down under a higher pressure load. I do know from aquarium and pond hobbies that a lot of pumps will pump a certain volume based upon how many feet of head. The longer the head the lower the volume and pressure.

Berserker

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99 2500 QC LB 4x4 Auto, Laramie SLT, driftwood. Cummins 24v w/ 275 HP injectors, Edge Products EZ & Banks Stinger Plus kit minus Ottomind, TST 10 level PM3, Stainless Steel fuel lines, EGT and Boost gauges on A-Pillar mount, Prime-Location fuel filter kit (removed pending outcome of testing), MagHytec Diff and Trans covers, ConFerr front heavy duty axle truss w/skid plate, EZ Change oil drain plug, BFG 35x12. 50x16. 50 MT's, Tuff Country 5” stage II lift-kit, Rhino liner, Smittybilt nerf bars, Warn chrome Transformer brush guard w/Warn12000 winch, Tow Hooks, Xenon fender flares & Abbott Electronic Ratio Adapter. DTT's Valve Body & Torque Converter.

MyTruck

[This message has been edited by Berserker (edited 12-08-2000). ]

 

[Vaughn MacKenzie]

This FLOW versus RESISTANCE stuff boils down to basic physics. You can use the principles of "Ohm's Law" from electricity, which describes the relationships of voltage, current and resistance, and apply it to fluids, to describe the relationships of pressure (voltage), flow (current), and resistance:

Ohm's Law Current = Voltage/Resistance

so applied to fluids

Flow = Pressure / Resistance

"Flow = pressure divided by resistance"

Plugged into this simplified equation you see that increasing pressure results in volume dropping proportionally. No IFs, ANDs, or BUTs!

There are many factors determining resistance to flow, however, it all means the same result: Flow is inversely affected by resistance!

Some variables affecting resistance:

Viscosity of fluid (higher vis = higher resistance)
Temperature (lower temp = higher resistance)
Diameter of tube (smaller = higher resistance)
Distance of tube (longer = higher resistance)

and so on.

Hope this clears up any questions.

Vaughn

 

[Dane]

For a given flow (volume per time interval), if you increase the head pressure the flow will drop. A smaller size pipe is the same as increasing the head. Sooo... When the pump sees a higher head pressure the flow will decrease unless the pump can draw more current and work harder to keep the flow the same. Bottom line - Smaller pipes flow LESS for the same pump pressure. Don't let em pull your leg. If you have a marginal lift pump and you increase head pressure (line size) you're going to have less flow (volume per time interval). Do the math PrimeLoc!

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2001 HO 6 speed Regular Cab SLT 4x4 3. 54 anti spin 2500. Used for the daily grind and sneaking away to some secret Baja beaches toting a cabover

 

[John]

Berserker, The PowerShop in Enumclaw, WA has been at the forefront of this issue! My Ram is one of the subject trucks that was involved. Chuck (the owner of The PowerShop) CALLED ME after he discovered the pressure loss on another customers Ram. HE CALLED ME as he and the rest of the crew at The PowerShop are top flight mechanics/technicians that pride themselves on the excellent customer service they provide. They knew I had a Prime-Loc system installed on my Ram... that's why he called me (Friday evening). . to schedule an immediate series of pressure tests (FOR FREE I MIGHT ADD). Chuck performed the tests himself early Saturday morning. In fact, he was more than happy to accommodate my schedule. This is why I continue to do business with The PowerShop... EXCELLENT CUSTOMER SERVICE with a proactive approach to problems (or possible ones).

Berserker, how much flow (volume) do you think my injection pump saw when we were performing the series of road tests (as in REAL WORLD TESTING) when, AT LIGHT TO LIGHT/MODERATE THROTTLE the gauge read -2. 2 psi? That's right, MINUS 2. 2 psi! We cut the road test short after that as we weren't about to possibly compromise my injection pump during full throttle testing. Have you read the original post (in this forum) that Evan Beck started? This will provide more insight to the problem. [Most of the comments were posted on the thread in the Product Forum although, there were others made on the companion thread in the 24v Forum. . also initiated by Evan Beck]

BOTTOM LINE: Even though I installed a NEW lift pump on my Ram, I'm still not willing to add ANYTHING, I REPEAT, ANYTHING that is going to reduce flow. PERIOD! That means pressure or volume.

... . sorry, I'm not going to whitewash over this thing!



[This message has been edited by John (edited 12-08-2000). ]

 

[Berserker]

I'm not trying to whitewash over this either so I'll assume that that is just frustration and not pointed at me. After all, I'm in the same boat and if anyone looks at my signature they'll see that I have my Prime-Loc removed as well.

Okay,

Then should we disprove that the Prime-Loc will deliver the same amount of fuel that the non-Prime-Loc system would? If volume and pressure are directly related because you need pressure to get volume (sounds right) then can't we do this easily?




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99 2500 QC LB 4x4 Auto, Laramie SLT, driftwood. Cummins 24v w/ 275 HP injectors, Edge Products EZ & Banks Stinger Plus kit minus Ottomind, TST 10 level PM3, Stainless Steel fuel lines, EGT and Boost gauges on A-Pillar mount, Prime-Location fuel filter kit (removed pending outcome of testing), MagHytec Diff and Trans covers, ConFerr front heavy duty axle truss w/skid plate, EZ Change oil drain plug, BFG 35x12. 50x16. 50 MT's, Tuff Country 5” stage II lift-kit, Rhino liner, Smittybilt nerf bars, Warn chrome Transformer brush guard w/Warn12000 winch, Tow Hooks, Xenon fender flares & Abbott Electronic Ratio Adapter. DTT's Valve Body & Torque Converter.

MyTruck

 

[Driftwood Ram]

I know this appears to be mainly an overvalved issue but check the service manual. The one I have for my '96 in the fuel system section shows both pressure tests and fuel volume testing with instructions and required results for both kinds of tests. Just my . 02 worth.

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96 2500 4x4 Driftwood auto Waren 4x boards pyro,boost,trans temp on a piller mag hytec trans

[This message has been edited by TRACY MURPHY (edited 12-09-2000). ]

 

[John]

Berserker, ONLY the top two paragraphs of my last post were aimed specifically toward you (as indicated).

[This message has been edited by John (edited 12-09-2000). ]

 

[Berserker]

John - Cool - no problems Bro. #ad



Berserker

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99 2500 QC LB 4x4 Auto, Laramie SLT, driftwood. Cummins 24v w/ 275 HP injectors, Edge Products EZ & Banks Stinger Plus kit minus Ottomind, TST 10 level PM3, Stainless Steel fuel lines, EGT and Boost gauges on A-Pillar mount, Prime-Location fuel filter kit (removed pending outcome of testing), MagHytec Diff and Trans covers, ConFerr front heavy duty axle truss w/skid plate, EZ Change oil drain plug, BFG 35x12. 50x16. 50 MT's, Tuff Country 5” stage II lift-kit, Rhino liner, Smittybilt nerf bars, Warn chrome Transformer brush guard w/Warn12000 winch, Tow Hooks, Xenon fender flares & Abbott Electronic Ratio Adapter. DTT's Valve Body & Torque Converter.

MyTruck

[This message has been edited by Berserker (edited 12-09-2000). ]

 

[Rambling]

I apologize in advance for the length of this post.

Disclaimer: The following is not in support of either side on the topic of discussion in this forum. I do not have a Prime-Loc nor do I have any affiliation with Ash-Land Technologies.

It is said a little knowledge is dangerous. If that's the case, I'm real dangerous. #ad
Please bear with me when I repeat something that is common knowledge. No slights are intended.
***************************************************************
A question was asked earlier, which is more important, pressure or flow? IMHO, unless the fuel injector pump is a boost pump ( I don't believe it is) , it would stand to reason the requirement would only be that a sufficient volume of fuel be at the injector pump inlet. Therefore, flow is more important than pressure. It is easier to measure pressure than flow as has been noted before.

Resistance to flow (liquid or gas) as we all know is measured as pressure. The trick is being able to obtain an accurate pressure reading when the medium ( in our case a liquid) to be measured is flowing. Obviously, the accuracy of the measuring device is important. Given that the measuring device is accurate , an accurate reading will be made of the pressure only at the internal interface point of the gauge. This may or may not reflect the pressure at the point we are trying to measure. A fluid flowing passed an orifice (port) can induce a low pressure point within the orifice. The faster the fluid flows the lower the pressure. Some old guy #ad
named Venturi noted this a while ago I believe. Turbulence at any point within the fluid will create a low pressure point. If the measurement point is at the turbulence point or creates the turbulence, the pressure will appear to be lower. I don't know enough about this stuff to know if or how the condition of laminar flowing could be a factor (told you I was dangerous #ad
)

With that said, I submit the following (has a nice ring to it, doesn't it? #ad

There maybe problem in obtaining an accurate reading at the stock filer mount when it is under different mechanical configurations. If I understand correctly, the Prime-Loc has a test port for measuring the pressure on the output side. The output is then sent to the output side of stock filter head on its way to the injector pump. Looking at Steve's stock post-filter data w/P-L, we see a trend of dropping pressure as the demand of the injector pump increases. If the stock post-filter data w/P-L is compared to the P-L test port data, there appears to be a fairly constant 3 psi differential. I believe the connection between the two points to be a very short hose. One would not expect a drop of this magnitude in this short of distance. If either a turbulence is created at the stock post-filter port or the flow by the test port has been altered to create a Venturi effect due to the installation of the P-L, the readings might be lower and could account for the drop in pressure over such a short distance. You could also get a negative pressure reading when the pressure is near zero.

Steve's data tends to support P-L's position that there is adequate flow based on the limited flow tests they preformed. That is to say, that at 77mph and 4 psi at the P-L output, there is more fuel than the injector pump and the return line can discharge. If the return line was interrupted near the injector pump in their test to measure the return fuel, this would be a more stringent test than measuring at the tank - less hose = less resistance means easier/more flow out the return line. Since the injector pump will 'suck' whatever it needs from the fuel line first, it would appear that in their test there is ample fuel supplied to the injector since no reduction in volume was noted.

However, the real question (which concerns so many) comes up under WOT. P-L's test did not include this condition which is why I called it limited testing. Zero pressure may only indicate supply = demand. John's negative pressure may mean the injector pump is demanding more than the system can supply or it may be the result due to a limitation in measurement as discussed. Variation in data from different owners could be due different measurement instruments(variation in absolute numbers not the overall effect observed), variations in the hardware (both P-L and stock) on each truck, mounting variations, and any other fuel line modifications that have been done and their variations.

It would take some doing, but measuring the return fuel at WOT under a real or simulated road test would of benefit to all at this point. I hope Ash-Land Technologies will attempt to perform this type of test.

As already been said but worth repeating, be concerned, be cautious. Don't be excited until the situation is thoroughly evaluated and it is determined there is a problem. If the pressure goes to zero and there's a reduction in fuel returning to tank, then we should get excited. Until then, unless someone has taken test data to the contrary or has a specification for the lift pump that indicates the injector pump requires a pressure (numbers we have are for the fuel system) at the inlet to function properly, let's be cool, due the home work, double check the results and come to a sound engineering decision.


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<font color=#990000>~<font color=#990000> '99 2500 SLT <font color=#990000> ~ QC ~ 4X4 ~ LB ~ Auto ~ 4:10 LSD ~
<font color=#000000>*<font color=#990000> BD E-brake<font color=#000000> *<font color=#990000> BD Autolock<font color=#00000> *<font color=#990000> Gear Vendor OD<font color=#000000> *<font color=#990000> Jordan Research 2020 T-brake <font color=#000000> *<font color=#990000> Bullhide spray-in Line <font color=#000000>*
<font color=#000000>*<font color=#990000> 2k Komfort 5'er - 9,700 lbs <font color=#000000> *
<font size=-2>... Lookin' for the 'RE' to go in front of my 'TIRED' so's I got more time to Play!... <font size=-1>



[This message has been edited by Rattlin (edited 12-10-2000). ]

 

[Evan A. Beck]

Back to the top!

 

[John]

Originally posted by Rattlin:


It would take some doing, but measuring the return fuel at WOT under a real road test would {be} of benefit to all at this point.

This is the ONLY thing that matters!

The PowerShop (Enumclaw, WA) was working toward this kind of testing although, I'm not sure they ever acquired the appropriate testing equipment to make this happen.



[This message has been edited by John (edited 02-24-2001). ]

 

[Mopar-muscle]

TTT

read the posts of BillW , and vaughn and rattlin on the second page , this relates to our fuel pressure vs. the actual data we should be looking for confusion , more to come elsewhere .