ISC transfer pump

[Ncostello]

My volunteer fire departments newest rig is a 2000 KME Excel Chassis Pumper. The engine is an ISC 330HP Cummins. When I change the spin on fuel filter, the manual specifically states to install it dry and let the transfer pump fill it before starting. Fine. It works great. When I turn the ignition switch to the on position something senses its empty and the pump automatically kicks on to prime the system and purge any air. It runs for a minute or so.



Then I got to thinking, what kind of transfer pump is it??? Maybe it would work on ISB's. Its mounted along the back side of the engine very similar to the ISB but its mount is much larger. Its actually a junction block for supply fuel lines and the two return fuel lines (injector pump return and cyl head return). I was suprised to notice the motor looks awfully similar to the Carter OEM ISB electric pump motor. At least its the same size. I'd say the lines are 1/2" on the supply side. So now I've got a couple of questions for any ISC gurus.



1. What are the specs of this lift pump if anyone knows?

2. Have you seen or heard of failures like the ISB's have?

3. Is the ISC injection pump fuel or crankcase oil lubricated?



My concerns are two fold. I'm wondering if this pump would work and be more reliable on my ISB than the OEM Carter setup. I'm also concerned about the likelyhood of the pump failing (like we've all read about) and causing the truck to run bad or ruin the injection pump... at a fire. At least if maybe the injection pump is lubed by the engine oil it will be spared a horrible death.

 

[A Johnson]

1. What are the specs of this lift pump if anyone knows?



I'm not sure what specs you mean if its volume of fuel I don't know. It does supply about 15 PSI to the CAPS pump for approx. 2 minutes after the engine is started and then shuts off.



2. Have you seen or heard of failures like the ISB's have?



Yes, although there are usually no symptoms other than you can't here it run, when it should be running. The lift pump is not as important to this system, the CAPS pump has a really nice gear pump in it that is of sufficent size to pull fuel from the tank, and the lift pump has a bypass in it to allow this. There are fewer failures due to the lower duty cycle, I believe it is the same motor, not sure about impeller size.



3. Is the ISC injection pump fuel or crankcase oil lubricated?



Oil lubricated to the cam housing only, the accumulator, gear pump,injection control valve, and distributor housing are lubricated by fuel.



A Johnson

 

[csevers]

The ISX uses what looks like the same lift pump as the ISB and ISC use also. We have had more of the ISC lift pumps leak than outright fail to pump. Cummins must have got one hell of a deal on those pump units.



Craig

 

[Ncostello]

Thanks for the replies. I'm glad to hear the ISC isn't as dependent on the transfer pump as ISB's. At least I shouldn't have to worry about it causing the truck to stop without notice. I do like the idea of the bypass. . is that in the mount (housing)? Thanks again.

 

[HVAC]

Lift Pump

I was curious about this same thing and consulted the local Cummins shop. I was happy to hear that the lift pump is only needed to establish a prime in the system and from that point isn't running. This seems like a better system to me. The gear pump takes over and does a more dependable job of supplying the engine.

 

[A Johnson]

Ncostello, the bypass is in the housing.



By the way I assume your pumper has a way to flash out the fault codes in the event of a check engine light. (usually a diagnostic switch to start the flash sequence, and then scroll thru the list with the idle adjust switch). The fault codes I find most prevelent on the ISC/ ISL engine are a 277, and a 456/268.



The 277 is usually a defective stator for the injector control valve and when it is active the engine will not run.



268 is usually a defective fuel pressure sensor. ( It may be low fuel pressure depending on how recent of a calibration you have in the ECM. )



456 used to be combined within the 268 fault and is a low fuel pressure fault and can be caused by air in the fuel or exessive restriction. This can happen after a filter change so just be aware that it may show up ocasionally after a service.



Good Luck,



A Johnson

 

[Will24]

Oh boy, a keeping mechanics employed truck...





We have a KME engine (unfortunately) and after driver training one night (when the truck was about 4 months old) the steering wheel lost all feel backing in the bay. Turns out the drag link FELL OFF the truck, COMPLETELY There was no nut to be found and bolt was laying on the ground, KME supposedly recalled all trucks possibly built that way then, but still, THAT scares me!





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[QRTRHRS]

After reading will24's post, I almost did not want to say this. You can always email KME and ask.

http://www.kovatch.com/

The KME plant is maybe a half an hour away from me. "keeping mechanics employed " hmm, they don't pay all that much.

 

[Ncostello]

I've not had the drag link fall off, but I have had numerous small bolts and screws come loose. We are constantly checking the tightness of the little stuff. We also had to have our Hale FoamMaster 3. 3 recalibrated because the factory didn't calibrate it properly. Other than that we've not had any problems.



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[R.E. Miller]

CAPS pumps and their lifting buddies.

Just to confirm it to any non-believers, the lift pump does by-pass, not quite the same operation as the ISB. It might seem like a better set-up on paper, but I have seen enough of these things with failed injection pumps. To me it is just disgusting to see a perfectly good base engine plagued by something as fundamental as the fuel system. The rotors in the caps pumps operate under extreme hair splitting tolerances, and is one of the things that leads to their trouble. It is sad though, because a good running 330ISC is a mean machine



Russell

 

[Ncostello]

R. E... .



I make sure we fill up with Performance Formula Stanadyne on each fill up. Always have always will on both our trucks.



Is there anything I can do to keep track of the fuel delivery on the ISC. On ISB's we use the fuel pressure gauge... but since the ISC injector pump pulls its own... what can be done?? I'd do anything necessary to keep this ISC going. We only put a couple thousand road miles per year on this engine. Its just the nature of the way its used. Will this help the injector pump last longer since it dont see high miles?



I'd be :{ :{ :{ if it quit and had to be towed back to station or somewhere else. We paid $250,000 for this machine. I wanted a 6V-92TA in it but we couldn't get one by the year 2000... emissions wouldn't pass by that year in a road vehicle.

 

[A Johnson]

You can install a vacuum gauge. Max spec is 10"hg at CAPS pump inlet. Of course less is better and I normally don't see over 7" on most applications. You should probably allready have a port on the outlet fitting of the fuel filter. Keep the fuel tanks full for cooling,and condesation concerns which I'm sure you do, and keep the air out of the fuel lines. Cummins recomendation is to use the primer pump for filling the fuel filter, as it only takes a spec of dirt to sieze the CAPS rotor and junk out the entire fuel pump, but I see you are already doing this.



The CAPS pump is a great idea and easy to T/S and repair. (except motorhomes) It just isn't tolerant of dirt or water, and overall not as reliable as preceding fuel systems. When the emissions get tighter, the controlling of the injection events also gets tighter and there just isn't any room for error when trying to meet the newest EPA mandates, I guess durability also must suffer to some extent when you try to keep costs within reason There have been several upgrades to the CAPS pump and calibration codes for increased durability. The transit fleet I take care of has had a lot less issues with the latest CAPS than the introductory model. I know it sounds like I'm a big apologist for the CAPS pump, I plead guilty. I like it. I wish it was on the ISB instead of the VP-44 which seems to be clouded in a big fog of mystery due to no one wanting to spend money on pump stands and fuel pump specific training. At least we can fix most CAPS failures without an entire pump, and I don't believe the logic and understanding of the CAPS pump is above the average backyard mechanic.



A Johnson

 

[Ncostello]

Thanks A. Johnson. Our tanks are not allowed to get below 3/4 unless at a fire... at which point we call the mobile fuel truck to fill it up when it reaches half tank. And I did read in the manual where it specifically states to not pre-fill the filter or damage could occur. So I let the transfer pump do all that. Were clean when we work on it. I treat changing filters like surgery... very clean. We keep the whole truck clean as a whistle. That should help. I think by doing all we can should keep us on the road for a long time.



By the way... Scheid diesel is getting the VP test stand and the ability to rebuild VP's at the end of March this year. They have people in training as this time too. They said they will be 1 of 22 places nationwide that is authorized to rebuild VP's and test them. Dan Scheid personally told me this at a get together at their Lafayette IN shop. Real super nice guy. Hopefully this will pan out and one can get a VP tested if any problems are suspected.