Hi John,
[email protected]#dy Hell is every beggar in the service industry out to get you. You
mentioned he is the same guy who serviced your pump during the rebuild
of the engine. Why the hell did he not remove the cold start advance
ball and throw it away when he serviced it last time if it was coming
loose (they take a while to fail).
The mechanism you describe is indeed a wax pellet activated cold start
device, you can see some of what it does from the outside it lifts the
throttle arm off the normal idle stop so that the fuel injected is more
than hot idle to help lift the cold idle speed, it also has a shaft that
goes inside the injection pump with a ball rivited and welded to the end
this ball is on an ecentric. As the shaft turns it pushes on the same
component the advance piston actuates so that it advances the injection
timing as well to allow for the longer ignition lag when the car is
cold. It is common in the diesel industry here to remove the cold start
mechanism and cut the ball off.
Why did it fail? Two reasons the wax pellet (that is exposed to engine
water to make it expand and contract) may have collapsed and or the pump
maybe sucking air in through the front seal. Why would that matter? As
the engine revs the pressure inside the pump rises and this advances the
injection timing if the pump is struggling for fuel it will suck air in
the front seal or may cavitate on the internal feed pump when it does it
suddenly loses body pressure and the advance piston swing's back to idle
position and hits the cold start advance ball if it does this often
enough the cold start ball will fail via a fatigue failure and fall into
the pump usually causing catastrophic injection pump failure. If you run
a Walbro pusher pump the injection pump is alway's force fed with fuel
and this is much less likely to occur (the wax pellet could collapse
still but that is quite rare). If running a pusher pump I have no
worries about the ball coming off but in a hot climate without a pusher
I would remove the ball.
The engine will run quite happily without the ACSD (automatic cold start
device) some NZ new cruiser came with it some did not as far as I know
all Australian trucks were never fitted with it.
John get an estimate of repair cost as generally this failure destroy's
the injection pump beyond repair. You maybe better off buying a brand
new injection pump off Maarten in the Netherlands.
Regards,
Craig.
John Byrne wrote:
Snip.