Throttle body
- Thread starter miser143
- Start date
It's usually an O-ring in there, but it all depends on what brand TB it is. But generally yes, you can remove the throttle body blade from the shaft, and pull the shaft out and you should see a seal or O-ring in there
What size is the o ring and if it worth fixing it or getting a 65mm throttle body
Scrapla347
Active Member
Sorry I don't know the exact size but I always have a box of orings from Amazon or Harbor Freight with a ton of different sizes and they always seem to work. Just make sure you get the rubber that's compatible with the fluids it might come in contact with like fuel or whatever.
I don't know the size. Would have to pull a TB apart and measure to get the dash number. O-rings are standard sizes so just a matter of matching it up. Also depends on what brand. This a stock one?
CAMTWO1070
Active Member
You can fix the o-ring like already stated but just know that once you break the screws loose and remove the disc its imperative to mark the orientation of the disc before removing and make sure its totally sealed after reinstalling by holding it up to the light....The holes on the disc are slightly larger than the screws and the disc doesnt seat perfectly if you dont reseat it right..
Another thing is I would use a Viton o-ring plus I would dab some silicone based vacuum grease on the shaft at the o-ring...If you dont have vacuum grease the same equivalent is di-electric grease and in a pinch vaseline works too...
Dont worry about disturbing the throttle stop screw to see if the disc totally seals up as youll need to drain down the battery and do a base idle reset and that entails dialing in the throttle stop and the TPS voltage..
Usually when the TB is leaking at the shaft means the hole has been enlarged slightly and oblonged from friction...I took my TB apart and bored out the hole on a drillpress and pressed in a bronze bushing then put a lil bit of vacuum grease on it..
One thing I noticed is that the stock pcv valves fall short of doing their job right and so therefore ive replaced my stock pcv valve with a fully adjustable one and believe me when i say it definately makes a difference in the way my engine idles and its throttle response and can feel when it transitions between idle and cruise...
Good Luck
Attachments
Last edited:
CAMTWO1070
Active Member
If you get a 65mm TB you may experience issues with idle quality etc as the stock tune is matched with the stock throttlebody and if you change the TB size it will throw the setting known as ITHBMA out of kilter and cause idle issues...
Im running a twin 61mm TB on my 351w and also running a 90mm MAF from a Lightning truck with an A9L ECU.
If you look at my tune settings below in order to get my engine to stop hunting with wild idle fluxuations from 450-900 when started for the first minute or two and have a high idle issue at times during the drive I had to do the steps outllined in the box and put the correct flow at idle so when I crank up my 351w engine it fires up clean and idles like a stock engine with zero idle hunting..
My tune settings are on the left and the stock tune is on the right so if youre considering upgrading the TB consider upgrading the MAF and getting a chip to make the appropriate changes to the tune so youre not on here screening the base idle reset and idle hunting posts on this forum looking for a miracle fix which are only temporary bandaids.
If you change the MAF to match the 65mm TB you must also change the flow numbers or the engine will run lean...This is a quick comparison between my 90mm MAF and the stock MAF
The Balancing Act And Why It Wont Jive completely when you change out the stock component/components..
When you mix up those two parameters, they fight for control over the idle engine speed:
- The Lower ITHBMA Effect: A lower value tells the ECU that the throttle body is practically airtight. The computer panics thinking the engine will stall, so it aggressively opens the IAC valve to compensate. This forces a high, floating idle.
- The Larger MAF Effect: Without your custom transfer function, a larger 65mm MAF to match the 65mm TB naturally reads a lower voltage for the same physical volume of air compared to a stock sensor. The ECU sees a tiny airflow number and scales back the fuel injector pulse width, making the mixture dangerously lean.
Where you see the 14.0664 setting is the feedback numbers of my AEM wideband controller and the LAMBSE settings are what my tune commands....
Its a process but when done correctly you get ba flawlessly running vehicle in the end result
Good Luck
Last edited:
Similar threads
