NEED HELP !!!! Mallory takes a dirt nap and damage to my front universals

[Bigsaint]

Thanks David... right from the Mallory site "the 4150 draws 5. 0 amps. @ 12 psi's". It comes with a in line fuse, which was not included in my first install, with a fuse rated @ 7. 5 amps. , I'm going to put it in (the fuse that is) when I do the install tomorrow.

Scott W.

 

[dresslered]

If that is true, you can mount the Mallory in the next county with the 14 Ga! #ad


(Actually, that is not completely true: 14 Ga will give a 10 degree C temp rise at 10-amps. )

[This message has been edited by dresslered (edited 05-25-2001). ]

 

[dresslered]

I've got a nice clamp on ammeter if we want to make some measurements. We could even hook it up to a scope to see the inrush current.

Nowel-
Nice to have you on the board again! What will result from bypassing the 6V offered by the ECM. My understanding is that it is only there to prevent overpriming before the engine starts. I can't imagine that anything detrimental would result other than possibly loosing a drop or two from the overflow valve.

[This message has been edited by dresslered (edited 05-25-2001). ]

 

[Bigsaint]

Okay, one last post before I'm off to the races. David, great to finally speak with you. I'm going to to wire in a relay, if for no other reason, peace of mind in regards to the ECM. It's only gonna add another 15 minutes or so to the job, I figure.

Nowel, let me know what you think about that filter issue with the Mallory, when you have time. I've been surfing a bit, looks like Mallory makes a real nice filter themselves, if in fact sediment is a factor.

Say goodnite cookie..... goodnite cookie #ad
#ad
#ad


Scott W.

 

[B. Gill]

scott,i have a filter before the pump near the tank and it is a spin on filter on a mount similar to what TT has told you about and it is rated at 10 microns(thats what i was told)
i have a pump that pumps fuel thru itself thus cooling and lubriacting itself,i have had it on for about 2 weeks now and have put close to 2800 miles on it ,so far no problems it pumps at 12 psi and draws less than 3 amps(i have measured it). i have used the power from ECM to trigger the relay, with 12 volts supplied from the battery.
how many miles were you able to get before the pump failed ?
thanks
bob

[This message has been edited by B. Gill (edited 05-25-2001). ]

 

[HVAC]

Dave, I agree, I don't see how omitting the two stage current feature would be detrimental. I have a switch on the dash to direct full voltage to the pump, no problems #ad


Saint, I didn't want to post this, but I don't have a filter pre Mallory #ad
I believe there is some protection at the fuel pickup though. Pretty sure the whole gauge assembly is covered with fine mesh. It was October when I had my tank apart(and fuel pickup/gauge assembly) and installed the Mallory. So far I'm real pleased with it. Note that I also have a 1/2" fuel pickup. Not sure that makes a diff. I still bet your motor is incinerated and the pump is OK. This was the case with CSuttons fried BG pump.
_____________________________________________
Nowel/Performance Diesel

 

[csutton7]

Big Saint forgot to mention the filter pre pump--I'm using the BG5000 filter---chris

 

[Un-Hemi]

OK. What Dodge/Cummins is doing is called proportional voltage drive. What that means is that they turn on and turn off the 12 volts (nominal) to the lift pump very quickly, so that the pump 'acts' like it's getting reduced voltage. It's the same technique that variable electric drills use to provide low speed with no loss of torque. You know how they buzz at low speed, well, that's the driver supplying 12 volts (or whatever the battery voltage is) to the motor, but switching it rapidly. As you squeeze the trigger on the drill, the 'on' time becomes longer than the 'off' time; the drill is seeing a higher *average* voltage, and speeds up. The buzz on my Makita is very noticeable. On a DC motor, if you decrease the voltage using a resistor, or other linear (or analog) control, the torque as well as the speed goes down, and energy is lost in the resistor as heat. With switching (proportional) control, the controller is either 'on' or 'off' with nothing in between, so efficiency is high.

Driving a relay from the ECM-to-lift-pump wire will present the relay (usually one with a substantial amount of armature mass) with a dilemma. At some frequency (usually quite low), the armature and contact will be unable to follow precisely the antics of the voltage activating the relay; it will chatter, and the relay's output voltage will not follow the input voltage. Unless the armature can follow the proportional input voltage, the advantage of proportional drive is lost.

It is my opinion that the VP-44 doesn't want to see full lift pump input pressure *while at cranking RPMs* Perhaps there is some internal parameter that is exceeded when the VP-44 has 12-15 psi on its input and it is operating at cranking speed. This is the *only* reason I can think of as to why they would go through the difficulty and expense of doing what they have done. Methinks the VP-44 is a high-strung (and expensive) beast!

Regarding wire size, the short run of #18 that drove the original pump would have minimal voltage drop considering its short length. Running #18 back 10 or 12 feet to a relocated pump,of course, would be impractical. The voltage drop would be too great; that's why #12 would be a practical minimum. What Dresslered said. (always wanted to type that!)

The factory pump (according to the manual) draws 12 Amps. I kinda suspect that would be some kind of maximum current or misprint. It seems that most aftermarket pumps of similar characteristics of flow and pressure draw far less. Unless someone else does it before Sunday, I will measure the current draw and the proportional frequency on the lift pump at startup and post it here. I have the technology!

Having said all that, if Nowel and David are not having a problem with their setups..... what else can I say? #ad


Respectfully submitted for your consideration.

Tom



------------------
Tom Glover - VE7DQ, C-GWTG
99 QC SLT, LWB 4x2, ETC/DGP, Wht/Agate, etc.

 

[Bigsaint]

SSHHHHH, I'm secretly posting from the D. B. terminal, at work. #ad


Okay, I picked up a relay, in between calls, along with two 3/8" NPT to 3/8" line brass adapters for the Mallory. The only relay that I could locate locally was a 20 amp head lamp relay, should work though as it has connections for 1) Batt 2) switch 3) ground 4)load. I also bought some 10 ga. wire to run to the Batt. connection on the relay and 12 ga wire to run to the load (Mallory). I will also install the inline fuse just in front of the hot lead (load wire) into the Mallory with the supplied 7. 5 amp. in line fuse.

Tommy T. , after much consideration, I decided that I'd rather have a clicking relay, than a possibly fried ECM, due to an amp. surge. While talking with Csuton, he described that his BG 220 (I believe) knocked out the 30 amp. fuse in his relay when the motor went toes up.

Nowel, no filter eh... . you know, I have the power vested in me to hit you with a HP penalty (seen that before ?) #ad
Your right about the screen on the inlet to the Mallory, I was looking at mine before, it's a real fine mesh. Should be interesting to see what mine looks like on the failed unit. Ooops, gotta go, here comes the SGT, ... ... ... ... .

Scott W.

 

[HVAC]

Tom Turbo, the reason Dave Dressler isn't having any trouble is because he is bone stock!!! #ad
Heck, he still has the plastic covers on the seats #ad
He won't even put air in his tires for fear his extended warranty will be voided #ad

 

[dresslered]

Hey Nowel! That was below the belt! I warned the Saint about you and look what it has done to him. "Come to the Dark Side, Luke. " Besides, I took the plastic covers off at 22,000-miles! Did you notice my hands shaking when you pulled out that "black box?"

Tom Turbo-
Very good explanation on the proportional voltage drive. I was under the impression that a constant 6-volts was supplied during the cranking process only and then it was switched to a constant 12-volts. I had no idea that we were controlling flow/pressure in this manner. I personally would be very leary of designing a system that would cycle considerable currents like this for any prolonged period as I would think that it would create a huge amount of "noise" throughout the electronics. I will be very interested in hearing your findings. If it really is a "must have" item, I believe that a solid state MOSFET circuit could be designed to track the ECM's commands while releiveing it of its stressful duties.

Bigsaint-
I might suggest putting the 7. 5-amp fuse close to the battery rather than at the fuel pump. If you ever had that wire short out, you will have a whole new set of problems. Hopefully the rain will let up for you this weekend.

------------------
David Dressler
2001 Driftwood 3500 Quad Cab 4x4, 155 inch WB, HO Cummins ETH/DEE, SLT+, 3. 54 LSD, Camper Special, Trailer Tow, Heated Leather, Sliding Window, Jacob's E-Brake, Rhino Liner, VDO Vision (pyro, boost, engine + diff. temp. ), Autometer Ultra-Lite (electric fuel pressure, vacuum), Weather Guard Diamond Plate Saddle Box, Tork Lift camper tie-downs, Mag-Hytec, Mopar Tow Hooks, SmittyBilt Outland Sport Bumper Gaurd, 2-LO kit, AND functional Halo light!
Bigfoot 3000 10. 11 Slide-in Camper. "Do it in a Dually"

[This message has been edited by dresslered (edited 05-25-2001). ]

 

[Archive]

Some systems use a Pulse width modulated signal to control speeds and flows, and this is hard on the actuator... Motors or what ever. . Others use the dividing circuit. . like someone mentioned. . running on 6 volts. . some A/C blower motors are set up like this. . (The PWD signal would be like turning a fan switch on and off to maintain a certain fan speed. . Just an EX. )

As far as others go. . What do U think of adding a relay to the factory pump to get rid of this signal, and get a constant 12V at the pump, to increase it's life. As long we are getting enough Voltage from the ECM to activate the relay. . Just an idea...
Bryan

 

[csutton7]

Ok boys the oem wire to trigger the relay turns the pump on for the 2-3 seconds and then turns it off and then when you turn it over it comes back on--just like the OEM set up--now sure maybe the pump puts out more pressure, but if the VP can handle 12-15 psi all day long I can't for the life of me see why it needs only 7psi at priming/start up-the system gets pressurized with the initial turn of the key and then these trucks usually start up within one or two cranks--maybe I'm wrong... ... --chris

 

[dresslered]

I re-read the lift pump modes of operation in the Service Manual that Tom Turbo was refering to. There are two modes of operation:

Mode 1: 100 percent duty-cycle with a minimum pressure of 10-psi EXCEPT WHEN ENGINE IS CRANKING.

Mode 2: 25 percent duty-cycle with minimum pressure of 7-psi WITH ENGINE CRANKING.

TractorNut-
I don't see that removing this mode will gain you anything. On the other hand, my engine starts up immediately, so I don't really think that eliminating this mode will do any harm either. The service manual specs MINIMUM presure requirements but not MAXIMUM.

But the fact of the mater still remains that somebody went to a lot of trouble to implement this mode. I think that Tom Turbo called it when he said that the "VP-44 is a high-strung (and expensive) beast!"

 

[HVAC]

Dave sez:

"Remember that you have 18-Ga wire running
from the ECM before it is converted to your 12 or 14 Ga. I now have a new concern: Your
ECM might not be designed to supply the current that the Mallory requirs. In this case, the 18-Ga should operate a relay which will then switch on/off a separately run source. "

A BIG 10 - 4 on that good buddy #ad
Your circuit is only as good as it's weekest link. That circuit out of the ECM isn't designed to flow unlimited amperage as you can imagine. I had a complete failure of that same circuit so... ... ...

Note my post above:

"Saint, I don't think that extending the hot wire for the OEM pump is the way to supply
power to the Mallory once you have relocated it. I think you would be better served by
installing a relay for the oem circuit to trigger, in which case the power would flow via a new and larger circuit to deal with the increased draw the Mallory would create. "

Furthermore, if the Mallory consumes 5 adc @ 12 psi, how much would it require @ 15 psi???
My pump is turned up and I believe Saint's is too. This would require more current I believe. I'm running #14 wire with good results.

BTW Saint, I'll bet you two dobermans and a weimeraner your motor is toast on your pump. ---------------------------------------------
Nowel/Performance Diesel


[This message has been edited by HVAC (edited 05-25-2001). ]

 

[Bigsaint]

Okay, I'm officially confused now. To relay or not to relay, question #1. Nowel,David, if I check my existing wiring and have a solid 12 volts, and the Mallory was to draw more than 5 amps, if I cranked it up beyond 12 psi's ( I only bumped mine up to read a soild 12 psi's at idle), wouldn't the in line 7. 5 amp fuse blow way before I could damage the ECM ? Is the OEM lift pump wired through the ECM for the sole purpose of allowing that 25 second surge of power when bumping the starter ? I'M SOOOO CONFUSED !!!!!!!!!

Scott W.

[This message has been edited by Bigsaint (edited 05-25-2001). ]

 

[HVAC]

Saint, I was editing my post while you were composing yours. Look at my post again. For further confusing #ad


"Is the OEM lift pump wired through the ECM for the sole purpose of allowing that 25 second surge of power when bumping the starter ? I'M SOOOO CONFUSED !!!!!!!!!"

Not solely, but the ECM is in charge of controling the lift pump. But that would work the same if you used a relay. The ECM still controls the relay.
We have been told that the ECM provides 6vdc at first(when you key the ign) and then when you bump it the voltage goes to 12vdc. I don't imagine it's necessary to vary the voltage since with the relay your going to get full battery voltage when the relay is closed. Sh/be fine.

Regarding hurting your ECM, you didn't hurt the ECM, you hurt the pump. I propose the ECM can't flow enough current to heat the fuse to breaking. Run your bypass in some more to see if the fuse blows. It would be interesting to install a amp meter at the pump to see what the draw looks like. My theory is your underdriving your pump and it doesn't like it #ad


[This message has been edited by HVAC (edited 05-25-2001). ]

[This message has been edited by HVAC (edited 05-25-2001). ]

 

[Bigsaint]

Thanks again, Nowel. One last question then I'm off to happy land (work). If my wiring was suspect for the demise of the pump, wouldn't I have seen it earlier than right now ? Would it take over 3 months for a faulty wiring set-up to cause the motor to fry ? Fortunately, I still have power coming back from the ECM, so I know that's not fried, right ? As always, not trying to second guess anyone, just throwing ideas out to discuss. I'm off to work in a few and will be there from 3-11PM (Eastern). If anyone wants to discuss this further or has a great revelation they want to share, please give me a call @ (973) 764-6155, ask the desk to transfer you to my voice mail if I'm out on the road. Thanks again for of the input. Oh yeah, Nowel, been meaning to ask you, what about pre-filters for the Mallory, the pic. , of mine is above and now I'm wondering if I need a bit more filtration as Mallory recommends a filter that covers down to 40 microns, and that ain't me right now. I guess I'm putting the cart before the horse now, but I am really starting to think that I have some debris in the gerator.

Scott W.

 

[Bigsaint]

Oooops, you answered my question while I was composing same, how'd you do that ? #ad


Scott W.

 

[Bigsaint]

Okay, now I'm cofused once again #ad
. The concern I have is over the ECM and it either not allowing enough amps. to power the pump or the pump gerator jamming/or motor failing causing an amp. surge. , possibly frying the ECM. I know that has not happened yet to mine, but right now the Mallory is either A) jammed with debris or B) the motor has died due to lack of enough amps. supplied or C) the motor has died and the pump is jammed with debris.

Here's what I do know... Nowel has been running with his Mallory set up with a relay and no problems. Chris (Csutton) has been R+Ding this lift pump issue for quite a while and he also agrees that a relay is needed. David D. believes that a relay maybe good insurance in regards to the life of the ECM. Tommy T. has a concern over the psi issue while cranking with 12, rather than 7 psi's and the health of the VP44. (good post, by the way Tom). B. Gill also has an aftermarket pump running through a relay and it's working well. (sorry I didn't respond earlier B. Gill, I have had the pump on for about 3000 miles now, about 3 months)Looks like it's a crap shoot, but I will install the relay with the new pump and see what I get.

I'm with CSutton on the VP44 issue, just my take, but what does it have a bypass for anyway, if not to return at a set psi ?

Tommy T. 's post does give me some concerns, though. Why DID DC put the time and effort into this 2 second surge when the key is on for lower psi's ? Hope I don't find out the hard way.

Scott W.