Taking apart LS3 throttle body?

[500hpbluez28]

I recently had some issues with a throttle body when I had it disassembled to be repowder coated after a solvent got on it and discolored the finish. A GM tech took it apart and reassembled it for me when I got it recoated. He told me before hand that he had not taken one apart before as when they have issues they just replace the whole throttle body. He took care when taking it apart to make sure he put it back the same way it came out. Well when I got it back and put it on the car, it showed on my display that my engine power was reduced and the car would not idle. I also had no gas pedal. I had a matco scanner and ran the codes and there were all dealing with it. I ordered a new gm ls3 throttle body and the car now runs just fine. I was wondering if anyone on here has ever taken one apart and reassembled it and had a similar issue or if there is someone here that knows something I might not know that the tech might not of done that caused my ported throttle body to no longer work correctly? Had no issues with it prior to have it taken apart to re powder coat it. Any help or suggestions are greatly appreciated as I would hate to throw away a perfectly good throttle body if it can be fixed. Thanks

[Bo White]

So I take it that it was ported and ran on the car and then taken back off for powder coating?

[SC2150]

Bo knows the ins and outs of these.

[The_Stache]

Had exactly the same issue after i painted mine...

The symptom is that the throttle blade is getting too much resistance (ie not aligned) within the 'barrel'. During start-up the ecu completely opens and closes the blade (for diagnostics) prior to start. Any change to the resistance values and the computer automatically goes into Limp Mode.

To fix! -
-Unscrew the screws holding on the blade about 1/4 a turn.
-Push the blade to the completely closed position (this is further vertical than rest position).
-While at completely closed position, Re-tighten the screws.

The blade should not bind in any position (even completely closed).

[500hpbluez28]

Originally Posted by Bo White

So I take it that it was ported and ran on the car and then taken back off for powder coating?

When I purchased it, it was ported and you could chose the color you wanted it powder coated. I chose chrome. Its been on my car for a year but recently the finish got damaged and I took it off to have a local guy repowder coat it for me. thats when I started having these issues.

[500hpbluez28]

Originally Posted by The_Stache

Had exactly the same issue after i painted mine...

The symptom is that the throttle blade is getting too much resistance (ie not aligned) within the 'barrel'. During start-up the ecu completely opens and closes the blade (for diagnostics) prior to start. Any change to the resistance values and the computer automatically goes into Limp Mode.

To fix! -
-Unscrew the screws holding on the blade about 1/4 a turn.
-Push the blade to the completely closed position (this is further vertical than rest position).
-While at completely closed position, Re-tighten the screws.

The blade should not bind in any position (even completely closed).

I will give this a try when I get back from my vacation. But I wanted to note that the gm tech could not get the throttle shaft out so it was left in when it was powder coated. I dont know if this would make a difference or not.