A question for any control module experts out there, what output from the EEC-IV is altered by the neutral drive switch input. (1990F250,2x4,351w,C6).

 

It's an input actually.. and it's pin 30.

 

The IAC solenoid for air intake, fuel pulse time to the injectors and spark advance to the distributor.

 

Thanks, thats interesting because I checked out a rudimentary wiring diagram I have and suspected that there could be some tie in with the ignition timing because my neutral switch stopped working around the same time my ignition timing stopped advancing.

 

I can't find a IAC solenoid on my print, could it be called something else?

 

Ford Fuel Injection » Idle Air Bypass (IAB) Have a read through this link.

 

Excellent, easy to understand articles, will keep that as a favourite.

 

yes, a great site for all EFI info. I was first introduced to it in a post by Conanski a few years ago. Great reference for the self test, codes and sensors/actuators and much more.