A question to ponder, or VE Head and Rotor wear!

[Mark Nixon]

What happens when a Head and Rotor go "bad" or "wear out"?
I ask this because other than taking a pump apart that has either scored a rotor, or physically locked and broken one, all I actually see the most is polished surfaces to indicate wear.

What actually HAPPENS when a VE "wears out" and are there symptoms?

I mean, we can all usually tell when the low pressure pump goes bad, the truck won't idle, it's sometimes hard to start, or when the H&R control springs break it can also be hard to start, but also won't rev right, or pops and carries on.

Noone has EVER mentioned a "worn out head and rotor", though.

Mark.

[RCCUMMINS89]

I was under the assumption that a low idle when hot was a sign of a worn out h/r.

[bmoeller]

Had the IP go bad on a Deere 4010 years back (around the time of the transition to LSD @500PPM). It is a rotary style pump as well. Never took it apart, but had hard starts, wouldn't idle properly, stalling and a miss off and on. Similar symptoms of a bad LP.

The plungers and barrels can wear out too. Warmer fuel would be thinner, and harder to keep the pressure up to pop the injectors.

[RCCUMMINS89]

I was under the assumption that a low idle when hot was a sign of a worn out h/r.

But at the same time.... I had these symptoms until I re-sealed my pump and it magically went away. Now, when I had these symptoms my pump was not leaking. So, it somehow fixed itself by me taking it apart and putting it back together. Which leads me to believe that it would be something to do with the vane pump, because maybe I put a couple vanes back in upside down?

[Mark Nixon]

But at the same time.... I had these symptoms until I re-sealed my pump and it magically went away. Now, when I had these symptoms my pump was not leaking. So, it somehow fixed itself by me taking it apart and putting it back together. Which leads me to believe that it would be something to do with the vane pump, because maybe I put a couple vanes back in upside down?

Turning the vanes around would put a fresh surface towards the ring and possibly improve pumping capability.
Also, it's possible that just cleaning the pump internally (I assume you used something like brake or carb cleaner?) would have helped at least a little.

I've found that a pump will sometimes idle different depending on if you have the vehicle parked down hill, up hill, flat, or at an angle. This may or may not be symptomatic of the vane pump OR H&R having wear.
All I know is it SHOULDN'T change no matter how it's parked and some do.

I'd say 95% of us park our vehicles on a flat surface, so it may never arise until it is very severe, but low idle, when it ran perfectly good before, can be a warning sign.

Mark.

[RCCUMMINS89]

I notice mine idles higher than normal when it is in the 40s and 50s once warmed up than any other temperature. Only time I ever noticed it idling real low was after a run over a pass or at freeway speeds when it is real warm outside (above 85degrees). But ya, my truck will idle a little high when I'm stopping fast, then idle down when I stop... weird stuff.

Otherwise doesn't miss a beat, easy to start, ect...

P.S. If I would have known what I know now, I would have replaced the vane pump components when I had the pump apart, went with solid rollers and high rpm return springs. Words of advice: don't ever listen to an injection pump shop. They think if anyone but themselves looks at a injection pump wrong, the whole world will have a meltdown and the human race will cease to exist. "I promise you, that if you open up that pump, it will never run again without spending close to $2k". So insulted...once in an injection pump, IMO they are more simple and common sense than a carburetor.

[bgilbert]

P.S. ..I would have replaced the vane pump components when I had the pump apart

Hijack.. Any upgrade parts or 'different' vane pump components available? How much we looking at for new stuff in that area?

[Mark Nixon]

There are new vane pump assemblies available.
IIRC, This includes the inner hub, outer ring and the 4 vanes themselves.

Mark.

[RCCUMMINS89]

P.S. ..I would have replaced the vane pump components when I had the pump apart

Hijack.. Any upgrade parts or 'different' vane pump components available? How much we looking at for new stuff in that area?

Good question, I'll call the shop and pull teeth to find out what that costs.

[Mark Nixon]

Here's a very informative and descriptive article on the VE pump, in fact, this the most in-depth I have seen anyone get on the VE:

http://mebonty.monobasin.net/vepump.html

Mark.

[RCCUMMINS89]

About $150 for a new vane pump.

Also just called 2 shops and both immediately asked, why? After some conversation, they both told me that it is extremely rare for the vane pump to go bad and when it does, it will rarely affect idle. The most common thing to affect idle, and hard starting (when hot) is a worn h/r assembly, a worn camplate, or broken return springs. The way to tell if it is the h/r is spray cool water on the pump and see if idle picks up.

[RCCUMMINS89]

OH, the other big thing they see is..... the small shim under the h/r sees all the "brunt" from jacking up the pumps like we do.... this shim is there to affect timing. There are numberous shims because of minor machining differences between h/r assemblies. When a pump sees many many miles of hard use it wears this shim out...causing us to increase timing over time.

Makes me think of David's over advanced timing when he went with a new pump. Could this of been why?

[Mark Nixon]

I may have a much cheaper alternative on the vane pump assemblies.
The shims are available in 1mm-4mm with an extra thick machinable one available for custom work.

Mark.

[RCCUMMINS89]

Mark, ya know better than just saying that without continuing.......................

[m880cummins]

OK,

On worn VE's.

I have heard of spraying cold water on the distributor head while running is a diagnosis for a worn cam plate and I found an easier way tonight.

I replaced the injectors to improve the smoothness and power of the engine. Injectors were good, pulled old ones which only had like 5 ft lbs on the retaining nuts. New injectors went in with a little bit thinner sealing washers, buttoned it up and started it. Would only run on 2 or 3 cylinders! No power at all! TONS OF WHITE SMOKE and POPPING! Timing wasn't moved today. Timing was 1/8" bumped 2 months ago and pin was ground and afc tweaked. The engine was constantly pushing air bubbles in 3 lines which were cracked while running and did not affect the engine running. Closed them up and proceeded. Tore pump side apart, checked FSS (was good) checked KSB (was good), changed over flow valve (no difference), backed timing to stock (no difference). I then remembered that the KSB increases case pressure slightly when engaged. The intercooled trucks KSB activates and with power is like an FSS. With 12v, the intercooled KSB extends out and blocks the flow of fuel to the return line thus raising case pressure. Doing this with a jumper wire, the engine within 2 seconds went from running on 3 cylinders to running on 6 with no air bubbles and a much higher idle (than it was). KSB activated idle was about where a stick shift truck with factory settings idles in neutral.

Conclusion,

The new injectors had close pop pressures and weren't beat up like old ones, the bubbly fuel supply couldn't build enough to pop them except once every few seconds. This led me to believe I have a head and rotor issue. The truck had the same symptoms as mentioned above such as, when in reverse and then hitting the breaks, the lurch would stall the engine, when hot, the engine missed badly and ran rough at idle, the full throttle RPMs would pop and blow white smoke, very low power, horrible fuel mileage (13-16 mpg).

I band-aided my pump for the next week hoping it won't crap on me. I'm buying a core pump, rebuilding it and if the core needs parts, I will ask my buddy who has half a dozen parts pumps. IF I FIND BROKEN SPRINGS in the delivery valves and cam plate area, I will buy all new springs for the 6 delivery valves as there are plenty of cases of broken DV and Camplate springs. With that, expect to see my homebrew VE rebuild......

Final conclusion ,

Is it just me or are there a lot more intercooled trucks with pump issues than non IC? I wonder if bosch changed the metallurgy of the rotating pumps to something more inferior or the changing of delivery valves and a different KSB put harder loads and wear on rotating parts. As for now, the '93 has a pile of puking metal spinning around that somehow keeps it going to and from school, shop and work.....knock on wood.

Peace out

Charlie