TECH TIP FOR DECEMBER, 1993

IN NOVEMBER'S TECH TIP WE ENCLOSED THE FIRST 4 REPRINTS OF THESLIDES USED IN OUR SEPTEMBER TECH SEMINAR. THIS MONTH WE ENCLOSE THE FINAL 4 REPRINTS. TWO OF THEM SHOW HOW MY INDUSTRY DETERMINES THE "CLOCK POSITION" OF AN ALTERNATOR. PLEASE NOTE THAT THE DIAGRAM LABELLED "CS130" ALSO APPLIES TO ITS SMALLER BROTHER, THE "CS121".(THE DESIGNATION APPLIED TO THE VARIOUS "CS" SERIES OF DELCO ALTERNATORS, IS THE OUTSIDE DIAMETER OF THE STATOR, EXPRESSED IN MILLIMETRES.)

THE THIRD SHEET IS A SCHEMATIC DIAGRAM OF THE PROPOSED 50 VOLT SYSTEM, TO BE IMPLEMENTED WITHIN THE NEXT 10 YEARS, AND THE FINAL REPRINT IS OF A BASIC 12 VOLT AUTOMOTIVE STARTING/CHARGING SYSTEM.

PLEASE BE AWARE THAT IN 1991 GM INTRODUCED A NEW SPARK PLUG FOR USE IN THEIR TRUCKS WITH GASOLINE ENGINES. THIS PLUG IS 1/8"LONGER FROM THE CERAMIC INSULATOR END TO THE HEX SHAPED DRIVE PORTION THAN STANDARD PLUGS. MOST SPARK PLUG SOCKETS ARE NOT DEEP ENOUGH TO PROPERLY ENGAGE THE HEX AND THE RESULTING SIDEWAYS TWIST HAS A TENDENCY TO, BREAK OR CRACK THE CERAMIC INSULATOR.

SOME OF THESE CRACKS MAY NOT BE VISIBLE, BUT THEY CAN CAUSE THE PLUG TO MISFIRE. THIS MISFIRE HAS BEEN DIAGNOSED AS A SLIPPING TRANSMISSION, DEFECTIVE TORQUE CONVERTER CLUTCH, ENGINE IMBALANCE, OR MALFUNCTIONING FUEL SYSTEM.

A PROPER SOCKET SHOULD BE OBTAINED FROM YOUR TOOL SUPPLIER, ONE MANUFACTURER IS KENT MOORE, THEIR PART # J39358.

SOME OWNERS OF 1992 CORSICA AND BERETTAS ("L" BODIES), EQUIPPEDWITH THE 3.1L ENGINE MAY COMPLAIN OF INTERMITTENT:

© WILL NOT START
© SURGES AT TIMES
© STALLS WHEN PLACED IN GEAR
© HAS "ENGINE SERVICE LIGHT" ON
© TEMP GAUGE AT CLUSTER INOPERATIVE

THE ENGINE HARNESS HAS FOUR WIRES WHICH ARE NOT COVERED BYCONDUIT, AT A SINGLE BREAK©OUT, ON THE PASSENGER'S SIDE OF THEDASH, NEAR THE MAP BRACKET. WIRE CHAFFING CAN OCCUR, CAUSING SOME OR ALL OF THE THESE CONDITIONS.

THE WIRE INVOLVED ARE:
1 INJECTOR CONNECTOR LEAD
2 MAP SENSOR CONNECTOR LEAD
3 WATER TEMOERATURE SENSOR LEAD
 AFTER REPAIRING ANY CHAFFED WIRES, BE SURE TO SECURE THE WIRES AND THE CONDUIT TO PREVENT "FLOATING" AND A REOCCURRENCE.

THESE TIPS ARE FROM ONE OF MY TRADE PAPERS, "THE ELECTRICAL CONNECTION", WHICH HAS ACCESS TO O.E.M. SERVICE BULLETINS.