8.3 ISC CAPS Injection Pump....

[CumminsPuller]

I have a friend with an FL70 and it seems his second injection pump is on its way out (Only 250,000 miles on the truck) and his warranty is gone aswell. What are his options? His last rebuilt pump cost $2019. 00 and the warranty covered that. His truck is showing no codes on the dash. He is on his way to cummins in Houston, TX to have them hook up some pressure gauges and run it on the dyno. If anyone has any ideas on what he can do or who can re-build it please let me know. Thank you.



Jason

 

[bmoeller]

Need a fuel filter change? If they have a lift pump, is it working properly? If it is electronic, any bad connections/corrosion?

 

[CumminsPuller]

Thanks for chiming in here. Fuel filter was changed. Not sure about the lift pump question. Spent two days cleaning electrical connectors. Has one we can not get off on the pump.



Jason

 

[R.E. Miller]

I'll throw in what I know. CAPS means something along the lines of cummins, accumulated, pressure system. Shame on me for not knowing the whole beef on these, as I have spent a fair amount of time working on them. I am sure that there are many others who know tons more on here. The CAPS pump is similar to the VP-44 in a few ways, it is sensitive to fuel quanity, quality, temperature, and it is rotary. It does however use oil to lubricate the two pistons that do the pumping, however, the rotor is subjected to fuel volume and quanity for it's cooling and lubrication. The tolerances are quite slim, and as you can imagine, the environment that these engines operate in, offer the whole thing no mercy. No excuses should be made, it isn't a briggs&stratton, but figure how many times the rotor has gone around at 250K at 1:1 Anyhow, the lift pump is not like the ISB set-up, it is only used during cranking to prime the injection pump, and has a unique housing to allow for it to turn-off and bypass with little restriction during engine running. This will allow you to check fuel pressure and restirction at one point, bump the key, and you'll see pressure while the lift pump primes, leave you guage on the pressure side of the pump, start the engine, and now you can check for restriction... ... I used to feel like I was cheating when I got to check two things with one guage, at one point Lift pump probs obviously lead to hard starts. The pistons and the springs in the front end of the pump were the source of early CAPS pump failures, but they have since fixed that issue. The other very important fact of this pump's happiness, is that the pressure in the accumulator module is what the ecm is asking for. If it is not, then the reason for that must be found, otherwise the accumulator and the ECM get into a big stink that leads to the engine and the operator wondering "WTF, where's the fuel, whoa, where did that fuel come from????" Performance goes to the dump, timing normally gets waaaaaay retarded at lower rpms, and you have a tractor pull smoke with tater-tot power... ... ... ... ... ... ... ..... and... ... ..... the longer it gets run like that, the higher the repair bill I don't know what is wrong with you friend's freighliner, but a guess would be accumlator pressure, there are a million other things I could chatter about this thing, but I don't know what the symtoms are. If the pumping parts of the pump are failing, it is easy to find, metal in the snubber valve, but you have to see it to know what it is. Also, the accumulator pressure is rather high, not like HPCR, but like 3-10K, and it is best to monitor that through a program like INSITE that Cummins sells.

I have flapped enough cheeks, hope this sheds some light for you, sorry to hear about it, have seen some bad situations myself.

Russell

 

[CumminsPuller]

Russell, thanks a bunch man. I guess I should have put some other things in my first post to let you know more about it. He said he can be on the gas and then feel like he is missing some fuel if he then dops it into neutral for a few seconds and let it idle, then back in gear and on the gas it is back to normal and all seems well. But it is getting worse day by day. Russell I would like to hear more from you if you have any more ideas.



Thanks,



Jason

 

[csevers]

Some more info

The CAPS pump can be broken down in to several parts and can be repaired the same way like the accumulator can be replaced by itself, or distributor, I believe unless the most recent update you can break it down in to 4 or 5 parts to service. Most failures I have seen are in the pumping unit. The cost of 2k is insane either replace just the affected section of pump, or look for better pricing, the prices have come down some. The ones we have been replacing are Remans at about $1500 to $1800 we have a fleet of about 20 trucks with the ISC in them they have been very expensive to maintain in there early life,every one has had at least one CAPS pump and a cam. One truck has had 4 Caps pumps in under 300k, but the last one seams the best so maybe they are getting the very big bugs worked out. Good Luck to your friend.



Craig

 

[R.E. Miller]

I think that the accumulator might be the issue, that or the wiring assosciated with it. The connectors had been updated to help eliminate problems that were caused by corrosion and fuel intrusion. Your buddy's truck might need that update, or he could have issues with the accumulator it self. Really need to hook the truck up to insite, and see what is going on to tell. If he was having distributor module issues he most likely would have been towed over to the shop by now. Good news for the future of this engine... . can't say too much, but CAPS>gone, HPCR>in, displacement up, that will be an awesome engine.

Russell



P. S. Good point Craig, pumps and cams are like PM's if you deal with fleet units. It really is too bad that the tappets suck, because a 330 ISC that runs right is a blast to drive.

 

[CumminsPuller]

Just an update on the injection pump problem: Come to find out injection pump was fine, and to prove how valuable our boost gauges in our dodges are? He had a boost leak at his turbo. A loose clamp was the culprit. And we could have probably found the problem had he had a boost gauge in his FL70. Now all is well and truck is running good. Cummins charged him $250. 00 for their troubles.



Jason

 

[A Johnson]

AHHHHH you gotta admit guys, CAPS is keeping you employed.





A Johnson

 

[HoleshotHolset]

R.E. Miller said:

"tractor pull smoke with tater-tot power"



ROTFLMFAO :-laf



Matt