Since I joint the forum I started to hear, ECU, Fuel Management......Computer stuff on our cars, I wonder how they work (functionality, principle, design......), anyone can tell me?

 

actually with the exception of teh GSL-SE, the ECU is really just a relay box, which primarially controlls the emissions devices. Everything else is mechanical.

 

On our cars the fuel system is pretty primative. Its analog, so there really isn't any 'computers' to speak of. The ecu, besides emissions, just adjusts the injectors' pulse width based on RPM and the reading from the AFM, and temperature sensors. Pretty simple stuff...

 

Can people tune their car with different, say injection pulse width......(more ways I don't know yet) AFM = Air Flow Meter? Why an Haltech cost ~$1000?

 

Unless you've got a GSL-SE or someone swapped EFI onto your car, you don't have an airflow meter, and Haltech EMS doesn't apply to you.

 

I was talking about the 1st generation OEM EFI systems, like those installed in the SE. The 2nd generation EFI sytems are digital, and are controlled by some sort of microcomputer. All later generations of RX-7 from 86 on, use a digital system.

Haltechs, Motecs, etc. are expensive because they're acurate, and they're tunable. Fuel only ecus still aren't that hard to make. Megasquirt is a DIY fuel only ecu, that if your interested in how an ecu works, I suggest you look into it. The part that is crucial (and thus adds expence) is the ignition portions of these ecus.

 

I got it now, thanks, I will do a search on the Megasquirt ECU.

 

You might want to look at www.diy-efi.org

Kerry

 

If you ever have a question on how something works, try www.howthingswork.com first.

http://auto.howstuffworks.com/car-computer1.htm

 

Does the ecu need temperature sensor inputs to fire the injectors.

 

to fire accurately yes.