Sudden droppage of RPM's and Throttle surges

Wayne Cox wmc_sr20@bellsouth.net
Tue, 24 Sep 2002 18:26:08 -0500


At 05:05 PM 9/24/2002 -0500, you wrote:
>car and when I'm idling and the fan turns on, I can
>tell cause it's pretty loud, the car starts to have an
>erractic idle from 450rpm to maybe 750, if you guys

The fan puts a load on the electrical system - the alternator &
battery.  They should have plenty of power to drive a fan.  But if
something is wrong, the extra load can pull the system's voltage
down.  That can F**Up lots of stuff in the ignition, fuel delivery, end EFI
systems.

I'm not sure the best way to check it.  But you can try measuring the
voltage at the battery and see if it drops a bunch when the fan kicks
in.  It should be 13 - 14 volts with the engine running.  If it drops,
you'll need to diagnose what's wrong, but I'd guess the alternator.

    -Wayne    '91 NX2k - '93 NK2k - '92 SE-R (parts car?)