I recently purchased a Holley throttle body for my 420a. It has a 57mm opening. They are always on ebay. Anyway, I installed it today but the car is not idling well. It does a VERY rough and unsteady idle. I noticed that in the back of the tb (the part that touches the intake manifold) there is a little entrance that comes out from the big round hole ( main air entry). The stock throttle body has one too but it is not in the same place. So I had to make my own gasket. Has anyone used this throttle body and confronted these problems? Please let me know. Thanks.

This is just a guess, but when you swapped out your sensors, you might have messed up yout IAC motor and need to clean it or replace it. Mine idles bad after I did just about the same thing. I've never seen a 57mm throttle body on ebay before though, can you give us a link? I've seen 52mm and occasionally the 55 and 60. I would think that it's your IAC motor if that's the only thing you have changed, before you got the bad idle. That's my best guess, but don't hold me to it.
~Jeffo


Hey, have you seen my new tail lights? Yeah, cool huh, get used to looking at them.

Holley makes a t/b for our cars? thats news to me and get the link i want to see too.

myspace.com/coastiecobb

Actualy thatlittle hole needs to line up with the manifold hole. that is the port for the IAC which as you know controls the idle. is the port on the holley on top of the TB as opposed to on bottom liek ours is?

Terry

i got one of those to, i got mine on, and had the same problem. so i got a new gasket, and it didnt match up at all (the bolt holes were the same and so was the main hole, but the idle control flange or something wasnt lined up, the thing you were talking about). so as a last attempt i put form-a-gasket on there hoping this might do the trick. and it didnt, so its laying in the basement collecting dust wile i have the stok one on again.

if you get it to work please tell me, but otherwise i hope this helps.

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the real skill isnt in the wrenching, its in the tuning and sorting out of the details once the nuts and bolts are tightened up.



70mm mustang TB
2 fuel rails (8-injectors)...in hand but not yet installed.
funtional chrome vette sidepipes (true dual exhaust)
75 shot nitrous
4000 watt stereo
and bunch of minor mods on her now.

I never even heard of a holley t/b for our cars

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98 Silver Eclipse RS ATX
CAI, header, bored TB, Apex N1, Pro-kit/Tokico combo, custom lower tie bars, cross drilled/slotted rotors

i think i have seen them in summit or jcwhitney. they are expensive as hell...nearly 300 bones IIRC

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2011 Nissan Xterra Pro-4x

2007 Kawasaki Ninja 650R

1996 Mitsubishi Eclipse RS-NX 75 shot, AEM CAI, P&P t/b and intake mani-SOLD

1964 Buick Electra 225-all original, all power options, 325hp, 445ft/lbs tq

both of you are wrong. Holley used to make ones for the 420a. look on ebay they surface up everynow and then. they are not billet, they are casted aluminum. Holley has not made them for a couple years.


Terry