freaky gauge jump @ idle +

[dork]

I have a 89 supra w/ PCM 351. I have converted to HEI (no more points) w/ new cap, rotor, wires, plugs, etc.., replaced starter w/ newer style, and replaced alternator w/ newer style.

My volt gauge flutters from 12 to almost 14 while the tach also jumps from around 600 to over 3000 at the same time. This tach jump is without any increase in actual RPM.



Any ideas what is causing this?



I have checked all connections for a lose ground, but continue to have problem. It runs great, but this has me concerned.

[silvtongdvl]

You forgot about the voltage regulator. Some alt. have built in ones - others do not. If yours doesn't - you will need to add one.
~S~

[Juice75]

dork - did converting to HEI make much of a difference? I've been thinking about doing it to my 89, but I was wondering if it is worth the money.