Hi all:

One quick question ....

On S4, does the ECU compensate when turning the headlights on at idle ??

Does it increase duty cycle of BAC ??

or does it do nothing and assume the engine can handle the increased EMF (electromag force) from the alt ??

Thanks for reading,
hugues -

 

The ECU will use the BAC to attempt to maintain the correct idle speed if there are any extra loads placed on the engine (within reason, of course).

 

Thanks for reply.

Do you know how the ECU sense the added load ?
On S5, there is a load module within ECU that has a pin input from headlight switch, but not on S4.

So, on S4, does ECU look at rpm drop (not consistent with current throttle plate position via TPS reading)
or does it look at something else like voltage drop ?

hugues -

 

Honestly, I'm not quite sure. I would assume that is based on RPM, because really, what else could it be based on?

 

No, it's not as sophisticated as you think.&nbsp There is not battery voltage compensation.&nbsp The BAC valve pulsewidth is set, and it is not variable.&nbsp Load it taken by a combination of RPM and pressure inputs - yes, NA still has a "pressure sensor".



-Ted

 

The ecu only senses load from items that it has a wire running to.

Power Steering, A/C, headlights and brakes would be good to add a tap into the A/C load or PS load wire to compensate though!

 

HUGUES: You might be interested in the last response I made to this thread: https://www.rx7club.com/forum/showth...5&pagenumber=2

The turning on of the headlights does indeed have an influence on the operation of the BAC.

Unfortunatly your problem really seems to lie elsewhere. Think ECU.