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View Full Version : Erratic tach with starter saver


Mike T
08-27-2003, 07:19 PM
I just installed a msd starter saver and now my Autometer Tach bounces and is unstable when you rev the engine. I seperated the tach wire from all the other ign. wireing and it did not help. If I unplug the starter saver the tach works fine.

Am I getting electromagnetic interference from the starter saver? Do I need a shielded pickup cable from the starter saver to my msd distributor?

msdtech2
08-28-2003, 08:51 AM
Here are a couple of things that could cause this problem, make sure the starter saver ground is located on the same ground source as the MSD Unit. The only wire that should be connected to the points wire is the yellow from the starter saver. What type of distributor are you using or is it a cranktrigger system? Also check the timing, if the timing is erratic this could indicate a problem with the signal stabilizer. If the timing is steady but the tach is still erratic, I would recommend shielding the mag pick up wires.
Thanks,
msdtech2

Mike T
08-28-2003, 10:05 AM
I have the msd billit dist. The saver is grounded at the same spot as the 6-al.

I will check the timing.

msdtech2
08-28-2003, 03:09 PM
Thanks, let me know.
msdtech2

Mike T
08-28-2003, 08:05 PM
The timing is stable at all rpm's but the tach is all over the place. I also tried hooking my tach wire to the yellow and white wire (hooked all 3 wires together) for my tach feed as suggested by someone else.Same problem .

msdtech2
08-29-2003, 09:05 AM
This would indicate noise issues to the tach, check the ground on the tach to make sure there is a good ground, as well as voltage to the tach. Route the mag pick up wires through a different location to see if this will help.
Thanks,
msdtech2

Mike T
08-29-2003, 02:45 PM
Then how come my tach works 100% without the starter saver just hooked to the 6-AL?

Mike T
08-29-2003, 03:38 PM
I routed the pickup wires a ways away (12 to 16 inches) from my tach wire and it did not help.

Without the starter saver I have my tach wire in the same harness as the pickup wires and never had a problem.

Maybe there is a defect in the starter saver? Who knows unless I send it back.

msdtech2
08-29-2003, 05:02 PM
The unusual situation is that if there anything wrong with it, it would show erratic timing, the only thing is that it may be affecting the input circuit on the MSD Unit so it could give erratic tach readings. The only way is to send it in for testing. If possible send it in to us or if it is a new unit try to get it exchanged for another unit.
Thanks,
msdtech2

Truckracer
06-07-2008, 05:59 AM
I routed the pickup wires a ways away (12 to 16 inches) from my tach wire and it did not help.

Without the starter saver I have my tach wire in the same harness as the pickup wires and never had a problem.

Maybe there is a defect in the starter saver? Who knows unless I send it back.

Mike - did you get your problem solved ? We have one doing the exact same thing.