DFCO on jbody ecm

[se_sun1997]

I recently installed a jbody computer on my 1992 corolla for an electronic management easier to program than megasquirt, but I have a problem that I did not suspect, I have a mechanical vss.... When I decelerate, the computer does not engage DFCO, is there a way to activate it without the vss?

thanks

[PopUpBlocker]

If you can figure out the PCM pinout for the VSS input, I would hook something up to that (variable or fixed resistor?) to supply some type of value for speed. Then set up DFCO operational range to enable at all speeds. It would of course then only be able to be controlled by RPM's tables but you would at least be able to use it and would most likely save more gas anyway.

[JMHZ2401]

DFCO has a few settings to engage DFCO. So I would think it should still engage. MAP, and RPM are also used.

I would have stayed with megasquirt over the J ECU.

[yoecotec]

You don't need activation of DFCO to proper tuned your car. Most on J's car don't activate DFCO in their stock Tuned... like 96-99 2.4 Twin cam.

Just tuned your VE Idle and VE (Rpm x Tps) with ST+LT Fuel Trims like i already told you. Don't forget to use Filter in your histogram otherwise you introduce lots of error in your VE.

[Leafy]

You'll just need to come up with some electronic speed sensor, or just put the enable speed down to 0 mph.

DCFO is important in a daily driver, its good for 2-6 mpg.

[BlurrSpeed]

I dont know much about the electronics involved so Id go with Leafy's latter suggestion of setting both enable & disable VSS to 0 MPH. This may not work due to the "Enable VSS". Then you could play with the MAP & RPM settings to get it tuned in.

On my 2005 Cavalier L61 2.2 my DFCO settings are:
Enable RPM - 1000
Disable RPM - 1075
Enable MAP - 29 kPa
Disable MAP - 34 kPa
Enable VSS - 16
Disable VSS - 15

The RPM works great down almost to idle & the MPH I have more or less matched to the RPM. The MAP needs a little work because around 40 MPH & just a little throttle it will go into DFCO.

Also on our 2002 Camry 2.4L (I think) 5 speed I have not been able to find the correct codes for my ScanGauge II to get any kind og MAP or vacuum reading. Im guessing you have the MAP hooked up.

Let me know if you need help testing this since I am working on a tune for better gas milage & have access to the Camry if its the same or a close engine.