View Single Post
Old 03-29-2011, 06:27 PM   #27 (permalink)
EcoModding Apprentice
Join Date: Jan 2010
Location: Newark, DE
Posts: 143

'91 CRX - '91 Honda CRX DX
90 day: 34.91 mpg (US)
Thanks: 0
Thanked 14 Times in 14 Posts
Originally Posted by msc View Post
If your DX is stock DPFI your going to need to monitor both injectors.
It's not. Over the years, I've gone from stock DPFI D15B2 to a D16A6 with DPFI, to D16A6 with MPFI, to a D16Z6 with OBD-1 conversion.

Originally Posted by msc View Post
For the input zener diodes I would go with a lower voltage then 5.1 volts. Anything between 4.0 and 4.5 volts would be a better choice. The purpose of the zener is to limit the input voltage below the supply voltage so something less then 5.0 volts should be used.
Agreed, but in practice the voltage never hits 5.1 volts. When I bench tested the circuit with a 50K resistor and 5.1V zener, I could max out my power supply at 31-point-something volts and the voltage at the test point (the uP input in practice) only hit about 4.9V. I believe the rated voltage is at the diode's rated maximum current. I was using a pretty hefty zener current-wise, so the trickle of current through the 50K resistor at 12V was nowhere near that limit.
  Reply With Quote