Classic/Antique Car Repair: starter altenator problem ???, volt amp, amp meter

Question
Hi Brian, so far nobody has come up with an answer for me I hope you can. My jeep 94's starter started working going rough, till it stopped/broke, i tested the battery and it is fine, i had the alternator tested and that is fine too according to auto advance. The question is: when I push started the car and had it runnning, and pressed the accelarator, i saw a spike on my voltage meter from the normal 14 Volts up to 17-18 volts, untill I let go of the accelarator. All the wiring seems to be fine. what can possibly cause this? The alternator has no adjustable regulator, and the output looked perfect on the test. I am putting in a new starter motor tomorrow, just don't want to ruin anything else. Never had a voltage problem before.

Thanks in advance

Answer
edgar:

Perhaps nothing was wrong - your volt/amp meter will "spike" or go above what you notice as it's normal range for awhile if you've started the car on a run-down battery.  If it STAYS there, then you need to worry!  Most all alternators nowadays are internally regulated and sometimes the regulating diodes can burn-out  - but I don't think that's a problem for you.  Good Luck.
Brian