AdamB
Petty Officer 1st Class
- Joined
- Aug 26, 2004
- Messages
- 251
Re: Auto TPI on marine Chevy 350
GM switched to speed density systems starting in 1990... no MAF, just a $20 MAP sensor. Later they switched to MAF and MAP sensors, but for strict emmisions.<br /><br />Wouldn't need to use oxygen sensor, just program the chip to stay in power enrichment mode (or open loop where it ignores oxygen sensor) and just program it according to known vacuum to stay at around 14.7:1 AFR or slightly richer given the extreme loads placed on the motor.<br /><br />I had a LT1-Editor for my old '95 Z28. That used a EEPROM which was erasable. I could change the AFR ever 400 rpms. Just programed the fuel injectors in miliseconds...<br /><br />I know of at least one source where they convert the older ECMS to EEPROMS... which would allow constant changing...<br /><br />Still, just thinking out loud.<br /><br />Will see how my truck conversion goes.
GM switched to speed density systems starting in 1990... no MAF, just a $20 MAP sensor. Later they switched to MAF and MAP sensors, but for strict emmisions.<br /><br />Wouldn't need to use oxygen sensor, just program the chip to stay in power enrichment mode (or open loop where it ignores oxygen sensor) and just program it according to known vacuum to stay at around 14.7:1 AFR or slightly richer given the extreme loads placed on the motor.<br /><br />I had a LT1-Editor for my old '95 Z28. That used a EEPROM which was erasable. I could change the AFR ever 400 rpms. Just programed the fuel injectors in miliseconds...<br /><br />I know of at least one source where they convert the older ECMS to EEPROMS... which would allow constant changing...<br /><br />Still, just thinking out loud.<br /><br />Will see how my truck conversion goes.