Car '96 EX 5-speed

I have a high output alternator in my car that is bigger than stock. The drag on the engine can make the car idle drop down pretty low especially if I have the A/C on too. Is there a way to reset the ecu for this?

 

Just disconnect the negative terminal battery for 10 sec and hook it back up. Start the car up and let it idle for a min or two w/o touching the gas pedal just so the ECU can relearn what the changes were.

 

You cannot teach an ECU, the ECU is programed and gets Info from multiple sensors. Once you turn the ignition on, the ECU scans thousands of times a second. If it hasn't detected the new part you added, than resetting it will do. zero.

 

True, but you can also reset the ECU to learn the new changes such as throttle blade cleaning, IACV & FITV cleaning, idle adjustment, etc as it now has better air flow with less restricted passages. All Data software even tells you to reset the ECU after doing an idle adjustment.

To make that relearn process work, the OP will have to convert to OBD1 and get his car tuned by using a chip P28 or a OBD1 P72 ECU.

 

I'll try this but I am pretty sure in the time I have had this I have had the battery disconnected.

 

No you cannot teach a stock ECU, however, it has the ability to learn and adjust to different modifications. Not resetting the ECU will make the ECU take longer to learn the new setup. That's why Honda, and any mechanic that knows what he is doing, will use the ECU reset procedure. Specially after any work has been done to alter the engine or PGM-FI related parts/sensors. The ECU will start calculating the parameters for the new fuel and ignition maps from the base ROM.

OP if you find that your idle drops with load it could be a dirty IAC valve. That is what it's function is. When there is an electrical load on the engine at idle. The ECU will change injector and ignition timings along with the amount of air that will bypass the throttle. (IACV)

 

Also try resetting your base idle. There is a screw in the throttle body that sets a base idle speed of 500 RPM with the IACV disconnected. You may need to add a little air to it to compensate for the increased load. The IAC can only add to the base idle, and it can only add so much.