Throttle plate seal - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 05-17-2010, 10:06 AM   #1
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: May 2005
Location: Mass.
Posts: 816
Total Cats: 41
Default Throttle plate seal

So I picked up an Auto TB from a forum member and while it was in good shape and I shouldn't have messed with it - I did.

I took care to mess with the teflon coating on the walls of the TB, however, the plate does not quite seal (If you hold it up to a light there's some light pass through in the upper corner).

Has anyone just removed the teflon altogether and been able to maintain a low idle? I'm convinced the high idle + teflon removal is more myth and fact.

-Zach
thasac is offline   Reply With Quote
Old 05-17-2010, 10:34 AM   #2
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

Teflon coating? Never heard of a TB with a Teflon coating. Most likely its just dirt and gunk on the interior. Clean it with some carb cleaner and a toothbrush and I bet it will seal again.
neogenesis2004 is offline   Reply With Quote
Old 05-17-2010, 10:39 AM   #3
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,860
Total Cats: 1,788
Default

the butterfly should never quite make a full seal.
Braineack is offline   Reply With Quote
Old 05-17-2010, 10:40 AM   #4
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: May 2005
Location: Mass.
Posts: 816
Total Cats: 41
Default

Quote:
Originally Posted by neogenesis2004 View Post
Teflon coating? Never heard of a TB with a Teflon coating. Most likely its just dirt and gunk on the interior. Clean it with some carb cleaner and a toothbrush and I bet it will seal again.
The 90-93 TB's have some sort of plactic/teflon coating on the intake side of the TB. It's a gunmetal color and looks to be just painted on with a brush. I suppose it was done to prevent build up/throttle sticking over time.

-Zach
thasac is offline   Reply With Quote
Old 05-17-2010, 10:56 AM   #5
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,860
Total Cats: 1,788
Default

never heard of this or seen anything that looks painted on...

Braineack is offline   Reply With Quote
Old 05-17-2010, 11:03 AM   #6
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: May 2005
Location: Mass.
Posts: 816
Total Cats: 41
Default

Quote:
Originally Posted by Braineack View Post
never heard of this or seen anything that looks painted on...
Wrong side, it's on the back. I'll take a picture of it when I get home.

It's pretty common on Fords, BMWs, etc.

It looks like carbon build up until you clean it at which point it becomes pretty obvious that there's some sort of coating applied - I swearz. Keith from FM has posted on the GRM boards before.

After spending 6 hours filing off all the unused bosses, smoothing flashlines and polishing the TB I'll be pretty pissed if I can't get this ****** to seal.

-Zach
thasac is offline   Reply With Quote
Old 05-17-2010, 11:03 AM   #7
meatbag
iTrader: (50)
 
gospeed81's Avatar
 
Join Date: Nov 2008
Location: Houston, TX
Posts: 7,357
Total Cats: 26
Default

Having worked with teflon (Xylan) coatings, and having 2 1.6L throttle bodies on hand I can safely say they don't come with any kind of coating.
gospeed81 is offline   Reply With Quote
Old 05-17-2010, 11:06 AM   #8
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,860
Total Cats: 1,788
Default

oh this ****:

Braineack is offline   Reply With Quote
Old 05-17-2010, 11:11 AM   #9
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: May 2005
Location: Mass.
Posts: 816
Total Cats: 41
Default

Quote:
Originally Posted by Braineack View Post
oh this ****:

that would be the **** and unfortunately it's causing the plate to not 'seat'.

The mazda shop manual just mentions a 'plastic coating' but I assume it's a teflon based coating.

I'm looking for the best way in which to remove the coating with using any agressive abrasives. So far, no luck.

-Zach
thasac is offline   Reply With Quote
Old 05-17-2010, 11:25 AM   #10
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

I don't see how that contributes at all to sealing. the bottom edge wouldn't even contact the bore.
neogenesis2004 is offline   Reply With Quote
Old 05-17-2010, 11:27 AM   #11
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,860
Total Cats: 1,788
Default

Every miata TB I've ever held to light has a halo around the butterfly...if it completely seals you wont idlez well.
Braineack is offline   Reply With Quote
Old 05-17-2010, 12:15 PM   #12
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: May 2005
Location: Mass.
Posts: 816
Total Cats: 41
Default

Quote:
Originally Posted by Braineack View Post
Every miata TB I've ever held to light has a halo around the butterfly...if it completely seals you wont idlez well.
hmmm ... I'll just bolt it up and deal with it later if I can't get it to idle.

I have a feeling I'm going to regret touching everything on this car at once ... too many variables.

-Zach
thasac is offline   Reply With Quote
Old 05-17-2010, 12:23 PM   #13
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

I still stick by my last point. I don't see how that "coating" on the back of the throttle plate has anything to do with sealing when the whole bottom half of the leading edge of the plate that does the sealing is the FRONT of the plate. Which btw, has no coating.
neogenesis2004 is offline   Reply With Quote
Old 05-17-2010, 12:32 PM   #14
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: May 2005
Location: Mass.
Posts: 816
Total Cats: 41
Default

Quote:
Originally Posted by neogenesis2004 View Post
I still stick by my last point. I don't see how that "coating" on the back of the throttle plate has anything to do with sealing when the whole bottom half of the leading edge of the plate that does the sealing is the FRONT of the plate. Which btw, has no coating.
I don't see it either, however, according to Keith at FM (based upon a post on GRM) they constantly get high idle calls after people have cleaned their TB and they've attributed it to a tolerence change from the removal of the 'plastic coating'. I can see how it could affect the air gap to some degree as the crap was clearly painted on after the throttle stop was set and as a result, the throttle plate sorta butts up to the coating. If you remove the coating but do not adjust your throttle stop then you could in theory end up with a larger than OEM air gap.

At this point I'm just going to remove the coating then dial in my throttle stop. Any Idle adjustment can then hopefully be done with the idle screw.


-Zach

-Zach
thasac is offline   Reply With Quote
Old 05-17-2010, 12:59 PM   #15
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

Right, you should be able to trim up your idle with the screw. Also don't forget to adjust the throttle cable. Twice now when I fucked with the TB area my idle was running high afterwards and it was because the cable was pulling the throttle open.

BTW Brain, how is your chiseled up throttle doing? AOK?
Faeflora is offline   Reply With Quote
Old 05-17-2010, 01:02 PM   #16
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,860
Total Cats: 1,788
Default

no...





Braineack is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
OTS Bilstein to motorsports ASN conversion stoves Suspension, Brakes, Drivetrain 5 04-21-2016 04:00 PM
Expected intake temps on the track? tazswing Race Prep 20 10-03-2015 12:04 PM
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
Time to start learning and play with tuning The Gleas MEGAsquirt 3 10-01-2015 10:30 AM
Leaky Wilwoods mx592 Suspension, Brakes, Drivetrain 1 10-01-2015 01:45 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 08:13 PM.