Using Two IAC valves

[Slow94]

Tried to experiment with using 2 IAC valves on my lightning by splitting the signal. What happens is neither will run if both are plugged in and you have to unplug one in order for the other to work. Is there possibly a simple explanation to why this may not be working? I'm assuming with both plugged in they aren't getting a proper enough signal or they are causing interference with each other. Anyone have any suggestions that could get it to work? Maybe add some diodes or something?

[decipha]

i doubt it has enough current to sink 2 iac's, careful could burn up the output

best bet would be to have the second iac go to a relay that gets its trigger from an unused output.

would be simple enough to write code for it just need a few conditions

Code: Select all

if on goto disable  //otherwise check enable criteria below

:enable
if desmaf > 1.9
if ect < 120
if rpm < 2000
enable iac relay
bypass air += xx  // this is to subtract the amount of airflow the valve provides so you can still dial in idle air

disable:
if act > 90 **backup if ect fails**
  -or- if rpm > dsdrpm+300  &&  dashpot ==0 && cttmr > 6
disable iac relay
bypass air -=xx

should be simple and do the trick

maybe use the fuel cap lamp output, unused anyway may not exist though. High speed fuel pump output would need some finesse to make do.

[Slow94]

Interesting. It's really only under very specific circumstances that I need the extra airflow. Once I get past those circumstances once it's no longer an issue as the truck continues to run. The first shift into gear with cold trans oil temps make for a huge load change and will shut the truck off. My truck has a very aggressive trans so it is violent. I can just blip the throttle some with that first shift into gear and she is fine and I can then go back and forth just fine. I may be just nitpicking.

[decipha]

that usually means the seal on the trans filter isnt secured or is leaking, has nothing to do with idle air

i take it you have a bigger pan, did you use the bigger filter for the larger pans? do you have a filter retainer?