IAC air hose delete or plug ?
 

Hey guys.

On my 94 miata, there is a 3/4 line out of the TB, i recall it's the idle air control hose.

I'm deleting my MAF on my miata and running an IAT sensor.

I was wondering, What do I do with this hose ? Do i still need to plug it in the air intake ?

If I can delete it, what is the procedure ?

Thanks

You plumb it back into your intake piping.

https://www.miataturbo.net/attachmen...ine=1426098301

Is it ok to put it there ?

Yes

alright thanks alot gesso

Can you delete the IACV if you plan on running an ecu like MSPNP along with the IAT and MAP sensor?

Yes.

But you don't want to.

The IAC(Idle Air Control) doesn't have any AIR hoses from what I recall....it's bolted to the Throttle body and receives it's fresh air from that before the throttle plate.

It DOES have coolant hoses (1-in, 1-out) that you can delete if you wanted to as long as you run the coolant lines somewhere else.

2 different ones on a 1.6. There is a coolant controlled one, and a ECU controlled one.

I deleted all my IAC piping and valves etc.....was a bit stressed about it but it has had 0 effect.

I made a plate from 2 mm ali using the old part as a template.

It vastly simplified (the goal) and tidied the engine bay up considerably.

NBs only.

1.6 only.

1.6: coolant temp based idle valve is the one mounted on the main intake manifold plenum, roughly between runner 2&3. Electrical load (AC, PS, head lights, etc) based valve is on the bottom of the throttle body and has a separate hose from post throttle body to pre throttle body.

1.8NA: same as 1.6 but without the coolant based valve. ECU senses coolant temp, uses the electric valve to compensate for both cold and warm starts, and for electrical loads. Somewhere in there (95.5?) they added a solenoid to the return line from the FPR, so during cold starts it increases fuel pressure. This is called cranking pulse in Tuner Studios I think.

NB: Finally Mazda plumbs a channel into the throttle body to eliminate the hose. I'm fairly certain 99-05 throttle bodies are all the same. Don't quote me on this.

Can you post a pic please?

Thanks.

Rafa

No pic, but here is the CAD outline for the block off plate I designed for NA8 throttle body. I made mine out of 3mm aluminium I think.

https://lastpixel.box.com/s/btvhmxer...spdiyt6ytgza0c

Hasn't made any difference to the idle on my car, but it was rough and horrible to start with. I also run the car in a warm environment and have time to sit in it to get it warmed up before events.

Thanks

zero effect--but my car runs like ass...

Pretty much. It has such a lumpy idle already due to high duration cams and low flywheel weight. IAC delete made no difference.