The alternator was checked using a device which measures the amount of charge going to the battery, and without a load it was about 14.75 and fully loaded at 12.5 at idle. The rebuilders said they replaced the diodes and they were confident they did a proper job; however, they noticed that at idle the charge would vary by 3/10ths of an amp(?) like from 12.7 -12.4 and they wondered if a clogged injector was causing the engine rpm to vary, as this variance would disappear as the rpm were increased. they replaced the volatge regulator as a precuation and i put some cleaning agent into the tank.
Is the idle rpm supposed to be contant, or will there be some variance, if so, by what %'age should it vary?