98Zheadsncam

iTrader: (26)

So, just as the title states, the motor wants to die for a second when the fan turns on. Brand new alternator in the car as well. Does my tune just need more rpm at idle?

Idle rpm is around 850...233/233 duration on the cam, 115+5 lsa.

old93camaro

iTrader: (8)

stick or auto?

MontecarloDrag

iTrader: (3)

Are the fans relays triggered by the PCM or by an independent controller?

98Zheadsncam

iTrader: (26)

Auto. TH400.

98Zheadsncam

iTrader: (26)

First fan is triggered by the PCM, and the other fan is on a switch.

The car has an independent air compressor for the boost controller as well. Turning that on also makes the motor stutter initially.


I should have mentioned, this is just a momentary stutter. After maybe 5 seconds, the motor idles up again.

eaglegoat

The computer can't see the increased load coming when you have things like this running independently. You probably need more idle air, more idle RPM, and more allowance for increased timing at idle.

98Zheadsncam

iTrader: (26)

Cool. I'm getting together with my tuner here soon; I'll let him know.

jimmyblue

iTrader: (11)

I'd be looking at ground straps and whether the new fan
is bumping the chassis sheet metal away from where PCM
ground sits. Also look at how fan power is taken off, from
what. Could be ground rise or voltage sag is to blame via
some sensor being whacked. Or just the step-load on the
alt, showing how near-death your idle tune is.

98Zheadsncam

iTrader: (26)

I'm pretty sure all the grounds are good...but I'll take another look. I know that even my 2015 fusion sees a slight drop in rpm when the fan kicks on...I'm thinking this issue on the hawk is due to the tune....not a big deal though, my tuner is more than willing to make adjustments free of charge.

Nicelysedate

iTrader: (3)

Might have to have this table bumped up. It adds air to idle as the fans turn on. It helps compensate for increased alternator load.

98Zheadsncam

iTrader: (26)

Oh, nice. I'll let my tuner know.


Between the electric water pump, twin Derale fans, air compressor, ice box water pump, boost controller, and six extra gauges...I'm thinking I should get a high amp alternator anyway, just to be safe.

eaglegoat

That won't do anything if it's not being qued by the pcm. The engine just suddenly sees additional load and didn't know where it comes from when a stand alone fan controller, or compressor, turns on.

98Zheadsncam

iTrader: (26)

The first fan is controlled by the pcm. I don't run the other fan all that often, so I'll take what I can get.

98Zheadsncam

iTrader: (26)

Just wanted to post an update for future reference.

My tuner came by and added just a bit of idle airflow via the IAC I guess. Cleared the problem right up.

Thanks again for your input, fellas!