i was looking in my chiltons rx7 guide, i had read that if you replace the engine, you need to replace the idle fuel contol variable resistor(if thats what its called)
I checked it with my meter and it was within spec, but when i turn it, it seems to do nothing. is it still good or am i looking at a trip to mazda?

 

If you read the Mazda manual is says Tamper proof for the resistor, and that's why it is supposed to have a wax covering over the screw. There are no adjustments available for that in the manual. Now from experience my 87TII had the cover missing and at the time I turned the screw back and forth and didn't notice a difference either. So I couldn't tell you what the possible effects of doing so would be.

 

if your idle is rough you can lean it out or richen it to make it smooth...

 

Okay guys,

The manual states that it should not be ADJUSTED unless the engine is replaced. Furthermore it wont do ANYTHING unless you follow the steps in the FSM were you are adjusting idle with the ISC jumpered. All that does is adjust idle mixture.

 

and if you find out what the specs on it are then...you can just use a regular variable resistor (like 50 cents) as opposed to the mazda one that probably cost like 20 bucks

 

i did actuallly follow the fsm, jumpered the connector and nothing seemed to happen. is it supposed to be a noticable difference? i have an air/fuel gauge(narrowband) and it doesnt move a bit when i adjust it.

 

yeah...you would need a wideband to see it...

 

wouldnt i be able to see an rpm change though?

 

There should be a rpm change. But not if the rpms at *idle* are 800 plus rpm already. The richer the screw is turned the smoother the idle.