89FormulaLS2

iTrader: (1)

I bought a ported throttle body for one of the two LS1 conversions I was going to do, last year. Got it, but never got around to installing it, just sat in the box. Sold it last week, and just got a message from the guy who bought it from me:

Anybody got any suggestions?

Raise

iTrader: (31)

maybe reset the pcm and go through a couple of drive cycles and see if it can learn the new incoming airflow. just my opinion.

jd13

iTrader: (3)

Check the idle screw. May need to lower it some (screw it in) so the blade closes all the way.

brandont454

its def getting to much air past the throttle blade somehow

HAMRHEAD

iTrader: (8)

Close the blade and reset the PCM

camaro98z28

Mine is doing the same

gwj

If the air inlet to the IAC was filled/redrilled it may be that the IAC plunger is sticking. Could be something got between the plunger and the seat. Mine did this when I first cranked it after reinstalling the TB , but the stepper motor made a hell of a racket then finally broke loose. From there I just did the idle relearn procedure. Also check the O ring for the IAC.

prostock_bigblock

iTrader: (11)

Looks like that u guys ported the hole in the throttlebody more than it should be . This one way to raise the idle sometimes.... I did that when i installed my cam untill I get my hptuners..

GM Muscle

iTrader: (9)

Is his car a '98-99? And what year motor was the throttle body from? If his car was a '98 or '99 and he put a 2000+ throttle body on the car his throttle cable will be to short cracking the throttle body open when it should be closed. The 98-99 bodies use a smaller cam on the end then the 2000+ throttle bodies use.

Bombguy99z28

Yeah, I've seen lots of problems when you switch years of tb's. Either the cam is too big and the throttle won't go down to idel, or it won't hit WOT, etc. If it is a dif year tb, you at least need to pull the mechanical parts (cam etc) from correct model year and use it.

cyphur

iTrader: (10)

after you check to make sure the years for the tb match up for the application, and have messed with the idle screw, forget the PCM. the tb's are VERY tempermental when you tighten the screws that hold the blade on the shaft. take the tb off the car, and loosen the screws, then swing the throttle cam open and closed a couple times. slowly tighten the screws while doing this, every couple rotations swing the throttle cam to ensure it keeps opening and closing freely. once your done, you should be able to open the throttle cam all the way, and then let go and it should close w/only the final snap when the throttle stop hits the housing, no sounds of brushing or anything. hope this helps!!

baddogz28

iTrader: (6)

There's a bigger than stock hole in the throttle body blade. I installed a Bauer racing TB last weekend and mine idles around 950-1000 rpm. It also takes time to settle down after a rev. No big deal in my opinion.

Neolloyo

iTrader: (3)

How would one go about doing the PCM relearn and also the idle relearn when they install a ported throttle body on their car.

This should stop the slight revving it does right now when I install it and also get rid of the cruise control effect when I let off the gas ..... right?

If not what can I do about it ...... It is of the same year vehicle and the hole in the blade is the same size as the one in my factory blade ...... I used a micrometer to check it.

LSonederfull

Yes does anyone know specific procedure including which fuses you pull?

spootnik

http://www.ls1.com/link_ecm.html

Ron@Vengeance

iTrader: (51)

What he said... If that doesnt fix it then the TB is just slightly over ported around the blade area and can be fixed with some minor tuning.