Originally Posted by mookymoo
These pumps have 2 modes of failure:
1) The points erode.
2) The piston corrodes/seizes. Ive seen 2 of these.
The facet or vacuum pump fixes both issues. Replacing the points only fixes one.
Saw the corrosion once. But in this case I think it was toast by over heat due to stuck points first - but then again it could have been stuck first -oh well. That pump actually caught fire. If the pump corrodes it must be getting wet internally. The points can handle wet - just not very long.
As I stated before I think the mit'zu pump is junk but the FET triggered by the points makes it near perfect. I'm STILL running the timer circuit. I've got a box of them so I'm good for 30yrs worst case! The vacuum pump is interesting but it's just wrong (philosophically-I know it works tho) to put it on the intake suction and the crank-case vacuum pulses (very astute) are subject to case vent changes and either way some find pressure to be excessive.