Gerald Morris
Senior Member
Greetings My Wise Moparians!
While my Taylor coil still produces enough spark to run Gertrude, last August's engine fire indubitably compromised that coil. I replaced it this past weekend with an NOS Delco coil made for Mopars, and VROOM!, spark MUCH improved! Alas, All yet needs be made Well....
I ran my old Stewart Warner tachometer unfiltered for over 3 years off that Taylor Vertex coil, with stock Mopar points, condenser et al, and only very recently began to see malfunction on that tach. It ALWAYS has malfunctioned with a loose connection inside, likely a result of a physical shock, which until recently, a gentle finger tap would set aright, giving good, consistent data. After severe rains since the New Year, this venerable instrument began to decay. It still measures SOMETHING from the coil, which increases or decreases as engine revolutions do, but doesn't accurately convey data. I have an Actron meter which I customarily use to tune the engine, with a reasonably reliable tachometer.
I purchased a shiny (PLASTIC! DAMN THEM!) Jegs tach for about $70 which clearly uses far more digital methods of measuring ignition pulses than the old Stewart Warner, which was made circa 1975. I attached the leads, saw the stepper motor inside run up and down to self calibrate the tach the first time, as per instructions, then started the engine. For the first minute, I saw my customary idle around 7-- rpm, THEN THE NOISE CAME.....!!! The needle commenced jumping all over the place, so I immediately turned the engine off, turned the ignition on to permit calibration again, restarted, again to some VERY noisy signal.
This came as no surprise, alas, as even my Actron meter now jumps some to noise off this Delco coil. Some questions have arisen to me at this point, which I seek your illumination for:
Shall I place a big old fashioned condenser on this coil? Such were used for AM radios, and this MAY help....
Are modern coils made with some remedial noise filtration from their outputs?
Would aged askarel permit noise more than modern equivalents? The Taylor coil also is so insulated, but it is nearly 50 yrs newer, as far as manufacture date goes.
Could my ignition be afflicted with some subtle short circuit yet? I HAVE looked, using continuity checks and such as my crude instruments allow.
Should I replace my ballast resistor? I can, and likely will, but suspect this won't solve the problem.
Is my veneralbe SW tach in fact still accurate, but merely AVERAGING noise pulse into the proper ignition pulse, thus showing higher readings than reality? Knowing a bit about analogue electronics, this seems probable, but I need more data. Old capacitors oft die in humid air....
Would a $32 tach filter be my best, most cost effective investment? I see one from Classical Instruments which looks acceptable. Have any of YOU used it?
Feel free to respond to these, and other queries which may NOT have yet occurred to me. I enjoy good electrical puzzles, except when my life or property might be adversely affected by them.
While my Taylor coil still produces enough spark to run Gertrude, last August's engine fire indubitably compromised that coil. I replaced it this past weekend with an NOS Delco coil made for Mopars, and VROOM!, spark MUCH improved! Alas, All yet needs be made Well....
I ran my old Stewart Warner tachometer unfiltered for over 3 years off that Taylor Vertex coil, with stock Mopar points, condenser et al, and only very recently began to see malfunction on that tach. It ALWAYS has malfunctioned with a loose connection inside, likely a result of a physical shock, which until recently, a gentle finger tap would set aright, giving good, consistent data. After severe rains since the New Year, this venerable instrument began to decay. It still measures SOMETHING from the coil, which increases or decreases as engine revolutions do, but doesn't accurately convey data. I have an Actron meter which I customarily use to tune the engine, with a reasonably reliable tachometer.
I purchased a shiny (PLASTIC! DAMN THEM!) Jegs tach for about $70 which clearly uses far more digital methods of measuring ignition pulses than the old Stewart Warner, which was made circa 1975. I attached the leads, saw the stepper motor inside run up and down to self calibrate the tach the first time, as per instructions, then started the engine. For the first minute, I saw my customary idle around 7-- rpm, THEN THE NOISE CAME.....!!! The needle commenced jumping all over the place, so I immediately turned the engine off, turned the ignition on to permit calibration again, restarted, again to some VERY noisy signal.
This came as no surprise, alas, as even my Actron meter now jumps some to noise off this Delco coil. Some questions have arisen to me at this point, which I seek your illumination for:
Shall I place a big old fashioned condenser on this coil? Such were used for AM radios, and this MAY help....
Are modern coils made with some remedial noise filtration from their outputs?
Would aged askarel permit noise more than modern equivalents? The Taylor coil also is so insulated, but it is nearly 50 yrs newer, as far as manufacture date goes.
Could my ignition be afflicted with some subtle short circuit yet? I HAVE looked, using continuity checks and such as my crude instruments allow.
Should I replace my ballast resistor? I can, and likely will, but suspect this won't solve the problem.
Is my veneralbe SW tach in fact still accurate, but merely AVERAGING noise pulse into the proper ignition pulse, thus showing higher readings than reality? Knowing a bit about analogue electronics, this seems probable, but I need more data. Old capacitors oft die in humid air....
Would a $32 tach filter be my best, most cost effective investment? I see one from Classical Instruments which looks acceptable. Have any of YOU used it?
Feel free to respond to these, and other queries which may NOT have yet occurred to me. I enjoy good electrical puzzles, except when my life or property might be adversely affected by them.