Really need some advice on this one. Port engine
has just been through it's 3rd rebuild
. The original problem occured at 3,000 rpms when the engine
shut down and basically cooked a piston. After rebuilding it with new pistons and new injectors it did the same thing again.
The next rebuild
included new injector pump
and valves. Now it is running fine but smokes beginning at about 2,000 rpms and progressively gets worse and the smoke gets darker as the rpms increase. It will run 3000 in fwd gear
but dumps unburned fuel
in the exhaust
and thick black smoke.
There are 13 hrs on it since the last rebuild. There is no blow by and the engine runs between 170 -188 deg until you bring the rpms up above 2500 then it creeps up past 195 at which point I back off the throttle.
Acts like it is overloaded but the installation
is on a Cat so there is an identical engine and prop on starb. Both engines run about the same rpm's at the same throttle positions. The Starb (good) engine will run 3000 RPM
with no smoke.
One final clue, the smoking engine idles fast (about 1,000) and has done so since the injector pump
Could this be injector pump timing?
Pat? Anybody? I am stumped.