I've read every post on this subject and was wondering i know the fsm doesn't say a throttle plate adjustment but is there anyone that could look at their secondary throttle plate stop screw (that has never been touched) and tell me if the plates are slightly open??
The reason why im asking is my air bleed screw on top of the throttle body won't change the idle unless i crack open the secondary throttle plates. And yes i jumpered the initial set connector. Is there anyway maybe to check to see what the mass air flow voltage is at idle from someones car then adjust the throttle stop screw to i see that voltage on my car?? Anyone have any suggestions???

 

They should be fully closed.


-Ted

 

I have a S5n/a and my hot idle is right around 500rpm(all three throttle plates closed fully) and thats with the air bleed srew fully open. Tps is dead on and all vacuum hoses have been replaced. I wonder why mazda put screws that adjust the plates open???
With the secondary throttle plate just barely cracked i can get 750. But i get a tiny surge with light throttle low load application. An suggestions???

 

I have the same problem with my GXL until I swapped on the S5 UIM. I never quite figured out WTH the problem was, but it works just fine now.

I've never found any resources that help witht eh adjustment of the secondary throttle screw either. Mine has been screwed with at some point (along with the variable resistor for idle fuel mix) and I'd like to get it adjusted properly.

 

sounds like the passages are clogged and a thorough cleaning of the BAC system is in order.

 

Have you made changes to the engine. Like remove the air feed line to the oil injectors spider? Removed the primary or secondary fuel injector air bleed air lines? Is this 500rpm with or without the initial set coupler installed? IF it is not installed and the engine is hot, what happens if you remove the plug from the BAC? No change in rpm? No change equals a pushed back pin in the plug or the transistor burnt out.

No oil injector spider and its air line means less bypass air. Less bypass air equals a lower idle. Same with removing the air line to the primary and secondary fuel injector air bleeds.

The screws were set with anti tampering wax/mud at the factory so the screws won't be messed with and cause the emissions part of the engine to, well, not work as they planned to meet emissions requirements.

Messed with the screw and got surging? I think the screw makes the linkage move and moving the linkage moves...............the tps setting. Just guessing right now on that. Fairly sure.