Idle problem

[Zakerid 10+ year member]

^?

A smaller pulley will spin the alt faster...

 

[Zakerid 10+ year member]

simpler

 

[jrwalte 10+ year member]

when i have my music off, its around 13.5 at idle then jumps up to 14.2 when i rev it.

13.5 is close to the floating point of the battery when charging so your alt is not putting out as much as it should at your idle - you want to be 13.9+. A smaller alt pulley will help.

 

[MECHMAN 10+ year member]

when i have my music off, its around 13.5 at idle then jumps up to 14.2 when i rev it.


you are saying there really isnt much i can do?

what size should i go with to get 2400 alt rpm?

You will always have a somewhat eratic idle RPM when your are playing music, because the regulator will be telling the ECM to increase and decrease idle RPM as every bass hit passes.

The low voltage at idle problem could be improved by decreasing the alternator pulley diameter. The idle RPM will still change under a load, but you will start off with better voltage. We custom machine 46mm pulleys in house, they are the smallest you can use and still get a nut on the rotor.

 

[slappinX 10+ year member]

You will always have a somewhat eratic idle RPM when your are playing music, because the regulator will be telling the ECM to increase and decrease idle RPM as every bass hit passes.
The low voltage at idle problem could be improved by decreasing the alternator pulley diameter. The idle RPM will still change under a load, but you will start off with better voltage. We custom machine 46mm pulleys in house, they are the smallest you can use and still get a nut on the rotor.

i just checked my diameter, since its in a awkward position i cant an accurate measurement but it looks to be 2-2 3/8 inch

how much for the 46 mm pulley shipped to 94803. It looks like i have to go down that path of a small pulley