99 TB Trouble
#1
99 TB Trouble
I really need help. This issue may have been covered before but cant find anything. I recently purchase a 99 miata, got a P0402 so looked it up and performed clean of the TB and intake. I used TB cleaner and cleaned it a little to good. Removed the soft seal around the Butterfly valve. Idles at 1500 to 1700 now. Have called around for a replacement but doesn't appear to exist. Don't want to buy a TB if can avoid it. Does anyone know where i can get a replacement seal or how to fabricate one.
#5
I understand what you are saying, but I've cleaned mine so that all that was left was shiny aluminum. I've never seen any sort of seal around the throttle plate nor a place where one belonged. It certainly wouldn't need a seal there anyway. Are you sure you didn't just wash away the ring of oily carbon that builds up around the edges?
Edit: Just remove the rubber plug from the idle air bypass screw on top of the TB and tighten it up a little to get your idle back under control. There is also a stop screw on the TB pulley if the bypass screw doesn't have the range you need. I can't find any data that suggests there's anything in there but a smooth aluminum tunnel.
Edit: Just remove the rubber plug from the idle air bypass screw on top of the TB and tighten it up a little to get your idle back under control. There is also a stop screw on the TB pulley if the bypass screw doesn't have the range you need. I can't find any data that suggests there's anything in there but a smooth aluminum tunnel.
Last edited by DammitBeavis; 02-28-2011 at 02:49 PM. Reason: One more thing...
#8
This is the only site that had a picture, several Google searches threads talked about the seal. http://www.cardomain.com/ride/210139...a-mx-5/page-12
#9
Fascinating. I went out and grabbed one of my '99 TB's in the garage and snapped some pics:
Stamping: https://picasaweb.google.com/lh/phot...eat=directlink
Dirty: https://picasaweb.google.com/lh/phot...eat=directlink
Clean: https://picasaweb.google.com/lh/phot...eat=directlink
Edit: Not sure why I can't attach images, but whatever....
Stamping: https://picasaweb.google.com/lh/phot...eat=directlink
Dirty: https://picasaweb.google.com/lh/phot...eat=directlink
Clean: https://picasaweb.google.com/lh/phot...eat=directlink
Edit: Not sure why I can't attach images, but whatever....
#13
LOL, it's on our own ******* forum.
https://www.miataturbo.net/general-miata-chat-9/throttle-plate-seal-47460/
If this is really on a '99 then you have the wrong TB.
In summary, don't worry about it, just reset your idle with the screw and/or throttle stop. Just don't set the throttle stop so that the plate can jam in the bore.
https://www.miataturbo.net/general-miata-chat-9/throttle-plate-seal-47460/
If this is really on a '99 then you have the wrong TB.
In summary, don't worry about it, just reset your idle with the screw and/or throttle stop. Just don't set the throttle stop so that the plate can jam in the bore.
#16
I started working on getting idle set. I have a scangaugeII and had it hooked up to compare to my dash tach. had car ready to go and was jumping the TEN and SGND. My DC has capability of pinning the KLN, TEN, +B, SGND FSC, and the FAB, IG-, GND, F/P. I was pinning the TEN and SGND when the car stalled. Disconnected jumper, and tryed restarting car but does not start, fuel pump work and engine turns over. I don't think I touched any other connection when tryed to jump the TEN and SGND but wouldnot swear to it. Does anyone have any ideas on what I may have shorted/done.
#18
To all was successful in setting idle. Jumped TEN to correct GND. the butterfly was open quite a bit since it took over 3 full turn to start getting idle to start dropping. ended up having to turn screw until it bottomed out, backed screw out half turn but could only get rpm to approx 1100. got fed up and just pulled jumper and low-and-behold had tach drop to 839-850rpm. Took for a drive and upon stop idle holds at approx 1100 and after a few drop to 850rpm. So i guess i got it right. Now just have to get car toshop to have Cat and O2 sensors checked to pin-point P0420 problem.
thanks for assist.
thanks for assist.
#19
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Sounds like this problem is revolved, but in the interest of cleaning up some loose ends...
The "seal" which is being referred to, between the throttle plate (the "butterfly") and the throttle body casting is not a seal in the sense that most people are probably thinking here; it's not an O-ring or a gasket or any discrete physical device. It's merely a surface treatment which is applied to the parts in the area where the plate meets the housing.
The thread that DammitBeavis linked to shows a picture of the area in question. You can see here a sort of grey coating all around the throttle plate:
The thread that DammitBeavis linked to shows a picture of the area in question. You can see here a sort of grey coating all around the throttle plate: