I was told how to change the Idle on a '93 Metro 2 door HB.

The screw on my throttle body (according to the fellow who told me
AND the Chilton manual) does NOTHING...

I actually screwed it all the way in w/o ANY change in idle speed!

I am now wondering if someone rebuilt the TB and put back a short screw!

If they put back a too short of a screw, the screw cannot go in far
enough to do its thing!

Does that sound reasonable? If I remove it and put in a longer one,
can I hurt the TB?

The manual says to put a fuse in the fuse box (adjustment fuse)(??)
before adjusting the screw on the TB.

What is THAT all about!?

DoctorBill

the fuse for the fusebox bypasses the computer so that you are just running on the air/gas/spark equation with no computer

you can adjust it but your throttle body has an actuator that adjusts your gas for you. It may have been adjusting your gas for you at the point when you tried to screw the screw in and it wouldn't reach. maybe by disconnecting the computer or bypassing it you won't have that problem and any time you perform timing or carb adjustments you have to bypass the computer either by way of that fuse or by disconnecting the computer. sometimes there is a disconnect wire for tyour computer but i don't know where that is at on a geo or even if one exists i know it does on chevy trucks