amount which in one embodiment was 0 003 inches 0 076 mm the pump is then ready 75 in the event that the threads are not engaged at this time the count is analyzed 86 and if less than 34 y 34 forward running of the motor is continued 82 until the count does exceed y or the threads become engaged if they still do not engage the number of cycles of reverse forward running is analyzed 87 and if equal to or greater than two the thread engagement is considered unsuccessful 89 and a flashing indicator 90 fig4 continues to be energized if the cycle count is under two it is repeated in the above mentioned embodiment the counts 34 x 34 and 34 y 34 are set to result in travel along the lead screw of approximately 0 025 in 0 635 mm in this embodiment these distances correspond to the distance of the length of the crest of one lead screw thread plus the distance of the crest of one split nut thread plus a tolerance amount in one embodiment as described by fig8 a limit on the number of cycles of forward reverse rotation is imposed in this figure the limit is two cycles another limit which may be imposed is a time limit for example the processor may limit the forward reverse cycling to a total of five seconds other limits are possible referring again to fig6 the flag 58 is placed on the same flange 41 that houses the pin 46 used to move the cam plate 50 to separate the split nut.