Tom wrote: Sun Nov 02, 2025 8:25 pm
Google says my binder paper feeler gauge is .004"
First, lol, and thanks!
Tom wrote: Sun Nov 02, 2025 8:25 pm
but know some throttle plates are beveled so they can sue up closer to the bore and still open/close. As I think about it, as a production part I guess it's not surprising to see gaps in this range. I'm guessing the gap grows as the temp rises (aluminum bore vs brass(?) plate). I recently joked to my machine shop guy that I wanted a part machined to within .002" and he said, "sure, at what temperature".
I also thought the plate was beveled and that maybe this plate was replaced or ground... but from your photos, Im thinking my adjustments snugged it more?
Would you try this throttle body? Or am I chasing a ghost here relative to my 1100rpm hot idle?
I worked as a machinist, our smallest tolerance guarantee was 0.003... but thats a excellent joke, I'll remember to use it.
Re: Throttle plate gap question
Posted: Fri Nov 14, 2025 6:25 am
by spacecad3t
I was flipping through this book and found this interesting quote about throttle gap...
Re: Throttle plate gap question
Posted: Fri Nov 14, 2025 2:48 pm
by johnb
This makes sense, since the idle stabilizer has a minimum duty cycle or somewhere around 25% in closed loop, and uses a fixed 30% when you deactivate closed loop control via the diag port. I assume the reason for the minimum duty cycle is to protect the solenoids from overheating.
Re: Throttle plate gap question
Posted: Sat Nov 15, 2025 7:57 am
by Lowencash
A most helpful source of web advice for our cars comes from YouTuber NCP44er. One such video involves rebuilding the throttle body. And while it would be best to ask the poster rather than rely on this reply, I'd have to say that I don't see a gap at all around the plate.
I see he's still taking questions/comments. Hope this helps.
PS: And I learned a new term today. He refers to the sharpie position marks as 'witness marks'. Never knew that! Can I get an Amen??? A witness???
Re: Throttle plate gap question
Posted: Sat Nov 15, 2025 8:28 am
by spacecad3t
Lowencash wrote: Sat Nov 15, 2025 7:57 am
A most helpful source of web advice for our cars comes from YouTuber NCP44er. One such video involves rebuilding the throttle body. And while it would be best to ask the poster rather than rely on this reply, I'd have to say that I don't see a gap at all around the plate.
I see he's still taking questions/comments. Hope this helps.
PS: And I learned a new term today. He refers to the sharpie position marks as 'witness marks'. Never knew that! Can I get an Amen??? A witness???
I did watch that video, great channel!
Re: Throttle plate gap question
Posted: Sun Nov 16, 2025 7:27 am
by Lowencash
spacecad3t wrote: Sat Nov 15, 2025 8:28 am
I did watch that video, great channel!
I would never, ever be able to get an engine that shiny and clean!
spacecad3t wrote: Sat Nov 15, 2025 8:28 am
I did watch that video, great channel!
I would never, ever be able to get an engine that shiny and clean!
Yeah that car is spotless, very jealous haha.
Re: Throttle plate gap question
Posted: Thu Nov 27, 2025 5:07 pm
by rheidtman
Hi - I rebuild all the 944 TB variations and is quite normal to have 'some' gap. Even if a person tries to reset the throttle plate screw, there will still be some slight opening. The key, as noted herein, is getting that tolerance to be small enough to avoid artificially increasing the idle speed.
Rick
Re: Throttle plate gap question
Posted: Thu Nov 27, 2025 6:14 pm
by spacecad3t
rheidtman wrote: Thu Nov 27, 2025 5:07 pm
Hi - I rebuild all the 944 TB variations and is quite normal to have 'some' gap. Even if a person tries to reset the throttle plate screw, there will still be some slight opening. The key, as noted herein, is getting that tolerance to be small enough to avoid artificially increasing the idle speed.
rheidtman wrote: Thu Nov 27, 2025 5:07 pm
Hi - I rebuild all the 944 TB variations and is quite normal to have 'some' gap. Even if a person tries to reset the throttle plate screw, there will still be some slight opening. The key, as noted herein, is getting that tolerance to be small enough to avoid artificially increasing the idle speed.
Post added to the other thread... Interesting TB and I've not witnessed the damage you highlighted. I have a number of TBs on hand and will review to see if any share those features... I also have 2 NOS NA TBs, but have to find them in the midst of my parts storage. I do think it important to document these nuances on the TBs.