KSB Fuel Line

[hotram03]

I just got this truck a few weeks ago and was hoping it was unmolested, well I was wrong, previous owner advanced the pump(who knows how much without visiting my snap-on man) turned in the fuel screw and crushed the fuel line from the KSB to the top of the pump. Does this effect anything? I also noticed what looks like a big spring around a pin coming out of the throttle shaft to be about worn in too, throttle moves alot before making contact and the truck even begins to respond, is this pump wore out?

 

[DValentine]

There are two hash marks -- one on the pump body on the flange that meets the block and an ajoining one on the front cover where the pump bolts on. You should be able to tell if the pump is radically out of spec if the marks are way out. The factory setting was with the marks lined up. The standard has been turning the pump an 1/8 inch toward the engine... . so you should be able to use that as a place to start.



The KSB advances the pump a few degrees at start up... . to aid in starting and smoke reduction. Cummins should have the part. Throttle should have some movement before the shaft start to move... spring loaded on both push and pull (from what I remember). The play that a lot of guys fix is the bell crank toward the firewall. I had a piece of copper tubing that did the trick.



Dave

 

[cerberusiam]

The KSB line being crushed probably won't allow full advance and you may notice some effect at startup but it isn't serious. Should be fixed though.



The bell crank spring being out and a lot of movement before the pump starts opening is more of a problem. There is a nylon bushing on the bell crank that is probably worn out an allowed the spring to slip out. Probably why there is so much slack. The throttle wouldn't return to idle. Fix the bushing and spring and crank the high idle open and you will have full throw on the throttle plus a smoother operating throttle.

 

[Greenleaf]

A pinched off fuel line will keep the pump at full advance cuz the bleed-off passage is now stopped and the fuel is dead headed inside said line. Thus, no internal regulation.



You may experience an over pressureization and pop a seal. The manual(s) explain the KSB operation in great detail.

 

[hotram03]

This bell crank your talking about is it the same one the 2 small return springs go to, because this is the one that the service manual says it should stay centered I think, it has a big spring under the throttle lever and the ends of the spring go around a small pin about 1/8 or 3/16th's in diameter when you give it throttle ends of spring move forward and contact small pin. The book also said you cannot take this apart as it is factory calibrated. Yeah I can tell the pumps been advanced, its slightly above an 1/8th" above the cam cover mark, How much of the fuel screw should be showing "Factory", because this has been turned in alot also I think there is only 2 threads showing.

 

[cerberusiam]

Hotram, I missed the boat, sorry. The spring you are referencing is the break over spring on the top of the pump (I believe). It can be taken off and reindexed and no the pin should not be half eaten thru (from memory).



Do a search here for "breakover spring" and see what you find. I know PB and others have posted info it and how to set it.



If there is no lock collar on the full power screw then it is likely to have been tweaked. Two threads showing is a long ways in. It may be time for a pump R&R.

 

[hotram03]

Thanks C, and your right its the break over spring, I remember the name from the service manual now, so I guess this pump is just plain wore out then huh? Jannetty's got a 230 hp pump I think for 1300. 00. I also found a place in Columbia,TN called Dixie Diesel, they said they could do what his does and then some for 994. 00, and thats them installing it for 150. 00 extra, dont know what route to take just yet, one I will have to save a dime or two just yet for this one. I didnt expect to have to put a pump on it right away.

 

[rlyons]

I wouldn't say the pump is worn out. My breakover spring was worn almost in two when I replaced the spring. You can braze the pin if it is worn too bad but you have to remove it from the pump first.

 

[hotram03]

I tried searching for some info onthe break-over spring but didn't find anything, is it hard to remove and re-index? Do I need a bosch service manual? And yeah the pin is about wore in to as well, what are this spring and pin effecting being this worn, anything other than throttle reponse? I dunno, anybody? Can you just get these two parts?

 

[cerberusiam]

Repairing the spring while not simple is relatively easy. The spring is probably the smallest problem if what you say about the fuel screw is true. All pumps are not equal but even with 200k and stock injectors the original pump on my 92 would have a) run away and BOOM b) layed down enough smoke to close down a 4 lane hiway. If the fuel screw on the back of the pump is down to 2 threads and you don't have serious drivability problems it makes me think the pump may be more than slightly worn. Dunno.



You should be able to pull the top of the pump and repair all that you can see is wrong and the pump may work for a long time yet. They are kind of funny about things and sometimes work a lot longer than their condition ever suggests they should. Fix the spring and see how it goes then worry about the other stuff later.

 

[Greenleaf]

If you's guys are talking 'bout that break-over spring they will wear through that pin that is centered between the two ends. I simply replace the spring and remove the lever and weld that pin. Then grind it back down to slightly larger diameter.



Break-over spring is Bosch # 1-464-651-430 about $18. 00 I have seen them worn nearly through and the pump is making well over 300 hp