any CAV injector pump experts here?

This message is a reply to an archived post by lyle niemi on July 26, 2011 at 09:49:13.
The original subject was "Re: any CAV injector pump experts here?".



OK since it was from an archived post it wouldn't let me reply to it...

I'm looking into a CAV DPA pump right now... it's from a day-before-yesterday's tractor, a BMC 9/16 Mini... 4 cyl 950cc diesel (little brother of the Leyland 154 that had the same chassis but a 1500cc diesel), and it has terrible acceleration... it seems that something is gummy in the pump but I've had the top end cover and top covers off and they look clean, I've had the advance mechanism underneath it apart and that polished it up a bit, it moves freely now, but still it just ain't right... if I rev the tractor up and idle it back down, it sticks in the idle position and won't get going again.. I knocked on the pump while it was stuck and it seemed to make the difference, it got going once again... I also removed the pump rotor and vanes at the back , but there's a tiny allen head screw back there I wasn't able to get... is it left hand thread? I didn't want to force anything.
As far as the "gummy" feel in the governor.. the internal throttle linkage felt just fine and moved freely, so I don't know what else would be messing with it.. perhaps I'll try the ATF in it for a while... I've currently got the head off the engine anyhow and may be re-ringing it while I'm at it, so I'll have some time to figure out the pump in the mean time

One big question... what is a happy injection pressure for these pumps? In other words the injector opening pressure.. is 2000 psi too high?

Lastly, would the pump from another tractor, like a Ford 3000, Massey 165, or something be fitable if the max fuel rate is reset? This pump has a 10ish spline female input shaft with 1 index spline

Any help greatly appreciated

I am certain you would not be able to use a pump from a Ford 3000 because it had a 3 cylinder engine.

DONT remove the allan screw..
Its loctited in and set to a critical torque from the factory.
IF the metering valve is free[under the top cover]
more than likely the hidden filter under the big 15/16 inlet nut is clogged up.

Still sounds like the metering valve is sticking. Do you have fresh fuel, or is it stale? As mentioned, DO NOT remove the allen screw in rotor end, pump will usually have other trouble than the screw causes. Service school showed how to test for leaks, seldom find any that leak. If it does engine will be very hard to start, if at all.