SORRY GUYS I need your help...
I think on my '84 Z28 HO the M/C solenoid is gone!

I've done all the tests suggested by the shop manual... basically the ECM send the signals to the carburetor, it receives them (measured it with an oscilloscope), but it's not able to regulate the air/fuel mixture (infact it's always too rich).

Where can I find a new M/C solenoid?
I'm Italian, so I'm not able to find it here and I haven't been able to find it on the internet.

In the worse case, I was thinking of replace the carb and the distributor to get rid of the electronics...

Thanks!

 

Doesn't mean the solenoid is bad. If you can hear it clicking when the key is turned to 'run' the MC solenoid is probably fine.

If it's far enough out of adjustment the ECM won't be able to go into Closed Loop and it won't be able to respond to O2 readings. Start with the basics:

Set your timing.

Check your TPS voltage, ensure that the voltage smoothly increases as the throttle is opened-this can be checked with key in 'run' engine off.

Adjust your Idle Air Bleed (IAB) per the shop manual until the readings show it beginning to respond to the mixture. Set the IAB when the MC dwell hovers around 50% at idle-when it's in Closed Loop the dwell will be constantly varying as it adjusts to the mixture.

If the above fails your carb may just need a rebuild-basically a thorough cleaning and new soft parts.

one internet source for parts is carbsunlimited.