Hello all
changed the oem TB to a used G2 52mm yesterday and after a test drive encountered this problem. Once the car goes no Nuteral the RPM gets stucked on 1500 for a moment and then goes down to ideal on 900 area kind of slow.
Ive checked the blades and they snap like crazy so no problem with them getting stucked on open. The cabel simes to work fine too.
What could be the cause and what would be the solution
Thanks in advance
Alex

 

The IAC is messed up sounds like. Take the one of your old TB, or get a new one.

 

Done it yesterday. A bit better but still not good enough
well - with the old one it was also getting stuck on open once i get it to the nutral, it was going on all the tiem. I had to hit the gas on nutral just to get the TB to close . With the ne IAC it did do the same but only once off the 1st gear. it still ideals very badly but at list it doesnt get stucked on some 2500-3k
I looked at the cable to make sure it doesn't get stucked somewhere - simes to do the job just fine and also when I open the TB manualy it works perfectly. Nothing get stucked and ideals right away.

Any more ideas guys. the car is drivable but drives like $hit right now . perhaps I need to adjust the cable some way (don't even know how)
thanks in advance
Alex

 

Did you try adjusting the throttle stop screw to get the correct idle speed?

The stop screw is reached from the back of the TB, upper corner, drivers side. Back the screw out very slowly (giving the IAC motor time to respond and stabilize) until you get the correct idle speed (stock is 800rpm for the M6, 550rpm for the A4 in neutral). When it has stabilized at the spec'd idle speed, use a scanner to check the IAC counts.... should be between 20-40. Then check the TPS voltage at closed throttle. Should be between 0.20-0.90V, and indicate "0%" on your scanner. Some people find they get the best results with the TPS voltage in the range of 0.50-0.67V, and you might need to slot the sensor screw holes to allow it to be moved.

 

Thanks Fred
I tought about that and whent to actualy do it but after a close look I think I figured the problem
the spring that pushes the blades back is kind of "not tight enough" and if I manualy (very lightly) push the trotle for about 1/16 it gets stucked there and most like this causes the whole thing.
now the whole cable connector and the spring simes to be adjastable since their is an allen bolt on the end of it.
The next thing for me will be to tly loosen it and see if it work better (maybe it's just overtightned) perhaps put some lube in it.
I realy don't know on how to adjust this spring otherwise.
thanks
Alex

 

I don't know who makes the G2 TB, but on my Holley 58mm, there are a couple of holes in the side of the TB for the end of the spring to stick into. Moving the spring to different holes adjusts the tension on the spring.

 

I just have to say that this site is incredible for
information. Injuneer's response, and those in
the know, provide tons of great information.

I just cut and paste all the little snippets of info
into Word as they come along. Someday I may
go to a 52mm TB and can avoid lots of the issues
by just saving key points from posts or searching.

 

100%


I don't know who makes the G2 TB, but on my Holley 58mm, there are a couple of holes in the side of the TB for the end of the spring to stick into. Moving the spring to different holes adjusts the tension on the spring.

Made by L.G. Motorsports - from what it looks like is the stock one borred to 52mm and slapped with the plate and the air foil

Here is an update
Remooved the TB for the third time yesterday
took it pretty much appart, cleanrd a whole bunch of crap out of it, lubed all the mooving parts and wsince the spring is not adjustible all i did is bent it for an aditional 1/2" on the back sideand changed all the sensors to the old once I had on the stock TB.
It simes to respond a bit better and at list it dosn't stuck on open every second time I push the gas but it still ideals kind of poorly.
it gets to about 1300 as it use to and then slowly goes down to ~900. it usualy ideals good when the car isn't mooving.
I did check the blades to make sure they don't get stucked somewhere - they look ok.

Oh yea. the most important thing to everyone who thinking to do the TB swap. Do the bypass right away and save yourself alot of headake.

 

you may want to reset your puter too. It may have a code for the bad tb.

 

sorry for the stupid question.
Never done it before so how do you do it??

 

pull the battery cables off for 10 min or so. It will clear the codes.

 

No need to pull the battery cable off and screw up the stereo because you forgot the security code. With the key "off", pull the "PCM BAT" fuse for 30 seconds. Done.

I'm not sure what codes you would have got for the TB.... if you had a TPS code, and the SES light went out, its gone, just stored in memory.

Sounds like you may have a gasket leak, and the IAC is struggling to pull the idle speed down. Are you sure you have the intake bellows correctly over the TB, and its not torn? Are you sure you have the TB tight and the gasket to the manifold is good? Are you sure you hooked up the connectors and vacuum lines? Did you have to swap the bottom plate with the IAC and coolant connections from your old TB? Did you use a gasket and correctly tighten all the screws?

Have you put a scanner on it, and checked TPS and IAC?