WYD_TRKR

Had my 2000 Trans Am WS6 Throttle Body Ported this weekend and since we reinstalled back onto the car, it wants to start with Idle PRM's running about 1500, then drops down to around 800 RPM's, before running normal. Also while trying to drive the car on the street, if you are running at around 45 mph and let completely off the accelerator the car keeps the same speed, as if the car was in a cruise control mode. My question here is what happened to the Throttle Body in the porting of it and can the IAC control be "Manually Adjusted to compensate for this high idle problem through a Tech2 etc? Any and all replies would be appreciated, as I am confused about what the car is trying to do since we had this mod done.

JF WS6

Did you reset the PCM after you installed it?

Slowhawk

iTrader: (12)

Did you try turning down the idle screw?A big help is getting a IAC count and go from there.

WYD_TRKR

Yes, we did reset the PCM, but evidently it did not help. Actually we reset it twice. Any other ideas? Thanks.

WYD_TRKR

Yes, we also tried to turn the Idle Screw outward to lower idle, but it made no difference whatsover. We also experimented with not only changing the IAC Motor, but also the TPS and no luck there either. Seems as though the PCM is trying to recalibrate the IAC, but it is not straightening the problem out. Any other ideas? Thanks.

SStrokerAce

iTrader: (2)

Who did the porting. I don't recognize your name, sO I don't think it was one of mine.

Anyways, take the TB off and look at how the plate seals in the TB, is there a gap around the blade? Also check the size of the hole in the blade. If there is a bad seal or the hole is too big then you have found your problem. If not it's a bad IAC motor.

Bret

WYD_TRKR

Bret, know of anyone that has a spare 2000 WS6 Throttle Body they want to sell me, as I think maybe some material was taken off the throttle body blade and this might be the problem? Please let me know if a throttle body is available, as I want to take this one off. BTW, this throttle body was done by a friend locally and do not know what happened to it, but it is not right.

robertbartsch

...for the sued TB, you may try Billy Graham's salvage on the net...

...just a thought...

robertbartsch

I self-ported my TB with NO problems. I really took huge amounts of material from the intake side of the TB: I left the exhaust side stock on advice from this page.

I also did the butterfly stop mod which is the MOST important part of the mod - from a performance stand point. (Your factory TB stop prevents the butterfly valve from opening 100%) This is designed so the F-bodies don't beat the C5's in the power department.

The other part of the mod I did not do was to block and fill with aluminum puddy the two vacumm pipes located at 10 O'clock on the intake side of the TB.

Did you use aluminum puddy and new vacumm tubes for this part of the mod?


I have read that, if the puddy-job results in clogging the new fabricated vaucumm lines that the engine will perform as you described.

Therefore, check the vacumm lines in the intake side for any blockage!!!!

SStrokerAce

iTrader: (2)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by WYD_TRKR:
<strong> Bret, know of anyone that has a spare 2000 WS6 Throttle Body they want to sell me, as I think maybe some material was taken off the throttle body blade and this might be the problem? Please let me know if a throttle body is available, as I want to take this one off. BTW, this throttle body was done by a friend locally and do not know what happened to it, but it is not right. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have nothing........

You found out why my TB's cost what they do, and why I don't touch the blade. You possibly have a junked TB. That sucks.

Bret

robertbartsch

I suppose a junked TB is possible, but these units are not that complicated.


What exactly did you port; just the aluminum throat before the butterfly valve right?

Did you plug the casting holes with epoxy for the two vacumm lines in error? Check this first!

Did you install the throttle cable correctly? Does the butterfly valve close all the way at idle?

Is the TB housing installed flush against the plastic intake manifold?

You didn't take the butterfly a part did you?

WYD_TRKR

Well guy's, I found out that my friend whom ported this throttle body, did indeed port the exhaust portion of the throttle body , that the blade fits into here. I know when this is done, that it can and will create a higher idling RPM and cause the IAC motor into playing havoc to constantly re-adjusting and it is confused as to the throttle blade having an air gap all around it now, to cause the problems I have been having.

I ordered a New Throttle Body today from GM and will have it to reinstall onto the car Wednesday, to fix my problems. I guess next time I will know better to have someone port the throttle body unit, without touching the throttle blade area and opening it up and causing these problems.

BTW, there was no other work done to the throttle body except porting the entire unit inside, all the way from the intake inlet through to the back exhaust outlet. Now, I just need for someone to grind down the throttle stop to open my blade 100%, verses the 90% factory stop.

robertbartsch

So the porting included removing material where the butterfly valve shuts at idle?

I assume there is now a big gap between the housing and the valve at idle (closed) position?

WOW (sorry) that was a bad move! Perhaps you could fill it back up with aluminum puddy????

Next time just download instructions from the web that show pictures and tell how each modificationis done. This would have saved a junked TB...Too bad!

jimmyblue

iTrader: (11)

Surging sounds like the IAC is busy but sticky.
That kind of thing makes for slow surging.
A lean-mix surge should not happen because
the air is MAF metered. However, a mistake in
reinstall (like, the intake O-Ring got out of
its keeper track and gave you a vacuum leak
that isn't MAF-metered) would be a wild card.
PCV makeup hose left off is another non-metered
air source.

A small air leak past the blade is only going
to elevate idle baseline if the IAC is not in
charge. You can test whether IAC is part of
the surging by disconnecting its connector
(though this might set a code).

Crud from the porting job left on the IAC
"lip" or bore might ba a source of IAC
function problems (sticking, or another
air leak it can't beat). Same for any dings
on the sealing lip. The IAC also has its own
O-ring, that likes to fall off. Still there?

The throttle blade you can easily inspect for
damage, just look at the edge for any non-
uniform (bright / scuffed) coloration / marks.

The unlit propane torch test would find any
vacuum leaks, if no external spots show a
response then it's inside the closed air path,
or the IAC itself.

99Z284MAC

when i had my throttlebody ported it was doing the same thing all I did to fix it was hit the little bar that sticks out off the throttle linkage it had been moved some how so i just tapped it down with a hammer maybe it will work for you.

Good Luck <img border="0" alt="[driving]" title="" src="graemlins/gr_driving3.gif" />

FACE

Hey Terry!
Still messing around with the GTP at all, or did this replace it?
Mike Boniface

WYD_TRKR

blowngs, no this is not a replacement for Blackie 1, but it is Blackie 2. Bought this one for a mid 12 second car and it does that right now. Good to see you in here.

WYD_TRKR

99Z284MAC, my problem was it was over ported and the erractic idle problem occured from the throttle blade not seating properly, meaning the opening was a little to big. I will just trash this unit. Thanks for the reply though.

white2001s10

iTrader: (4)

Please don't trash it. I want it.
Seriously, that's exactly what I'm looking for.

How much you want to ship to Illinois??
email me please
olympiadis@hotmail.com

thanks!
<img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

white2001s10

iTrader: (4)

I hope you see this before it's too late..

<img border="0" title="" alt="[Frown]" src="gr_sad.gif" />