[peklngduckk]

Hey guys,
I took off my throttle body + iscv to fix my idle problem (wouldn't idle below 1200rpm). Anyways, as I was cleaning the butterfly valve with throttle body cleaner, I held it up to the light and saw that some light was shining through. I understand it's suppose to be fully shut, so this is a problem.

I made sure it wasn't the dash pot, or the throttle body screw ( the one we aren't suppose to ever ever touch). The butterfly valve can't be closed anymore beyond what you see.

What should I do? Time for a new throttle body?

and what the hell are those chunky bits on the rim of the BV?




Bonus question: how the hell do you remove the actual iscv from the solid bit? There's only 1 screw holding it in right?

Thanks all

 

[babydriver]

isn't there supposed to be a small space between the bv and tb? the chunks are probably just buit up carbon..

usually you just spray some tb cleaner in there and its good. no real need to remove it, but now that you have, youll likely need a new gasket as its usually destroyed when you pull it off.

but yeah i just clenaed mine and read up on it and there is supposed to be a small gap there.. pretty sure anyway

 

[imnatelol]

If it was fully shut how would the engine run? There's a gap for a reason.

 

[peklngduckk]

Ok now I'm confused. I've read everywhere that the butterfly valve should be fully closed at rest. I'm assuming that means no gap. And everyone is always talking about the mysterious coating that seals our butterfly valve at rest. So are there suppose to be gaps or not? If so, how much?

Edit: plus I thought that's what the idle adjustment is for

 

[imnatelol]

Yes there needs to be a gap. This is a fuel injected car. The idle adjustment adjusts how far the flap is open at rest.

 

[tail dragger]

^
This is just ignorant and uneducated.

There is no gap. There should be no gap. The idle controller has nothing to do with the throttle body butterfly.

Buy another one.

 

[imnatelol]

Prove me wrong...

 

[Phuqer]

Funny, the Mazda 6 throttle body I just had off today also had a small gap, I guess Mazda (edit. make that Ford) is ignorant and uneducated.

OP, your throttle body is fine, these things do not fail on Miatas.

 

[PoLarryT_]

There should be a slight gap. Reason being is the engine still needs air to bring in from somewhere for the air/fuel mixture. If the the throttle body was fully closed you would fully be choking the engine

 

[95MerlotM]

^
This is just ignorant and uneducated.

There is no gap. There should be no gap. The idle controller has nothing to do with the throttle body butterfly.

Buy another one.

Who is ignorant now? :lol:

 

[tail dragger]

I guess all three of my Miatas are running with bad TBs. Ive had to replace a few over the years for this reason. Ive pulled out more hair chasing these problems than big foot has on his balls. I have made a point to clean the throttle bodies correctly and ive never had an air gap thats visible to the eye on one that I will use on a car. There is plenty of info that suggests either way will work however if you clean the throttle body and have to adjust somthing else to compensate something's not right.

http://forum.miata.net/vb/showthread.php?t=521573

http://forum.miata.net/vb/showthread.php?t=408462

http://forum.miata.net/vb/showthread.php?t=55703

http://forum.specmiata.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=44;t=003902;p=0

 

[thasac]

I guess all three of my Miatas are running with bad TBs. Ive had to replace a few over the years for this reason. Ive pulled out more hair chasing these problems than big foot has on his balls. I have made a point to clean the throttle bodies correctly and ive never had an air gap thats visible to the eye on one that I will use on a car. There is plenty of info that suggests either way will work however if you clean the throttle body and have to adjust somthing else to compensate something's not right.

http://forum.miata.net/vb/showthread.php?t=521573

http://forum.miata.net/vb/showthread.php?t=408462

http://forum.miata.net/vb/showthread.php?t=55703

http://forum.specmiata.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=44;t=003902;p=0

Taildragger is correct.

This said, even if you have unintentionally removed material causing an increased air gap, you can compensate with the idle adjust screw under the rubber cap.

-Zach

 

[peklngduckk]

Can confirm there ISNT suppose to a gap. Car's base idle now can not be adjusted to 850 rpm. Lowest it'll go is 1k. The idle adjust screw is turned all the way