LQ4 intake swap for a 4 bolt 90 mm TB

[genXhunter]

Ok. Got the plug in and plugged it into the 90mm TB loose to make sure it would work. It worked great until I got to full throttle and it shut down and sent a reduced engine power dash light. I had this same problem when I tried to put an 80mm BBK TB on my engine. Would not be able to open all the way before it tripped the reduced engine power shutdown. Thought it was something with their TB setup but now I am thinking otherwise. Has anyone else encountered this problem and is there an easy fix? The last time we had looked in the tune, the TPS was trying to read past 100% which triggered it. Anybody???????

[PitchBlackC3]

Are you using the DrX ?

[genXhunter]

I am using the adapter from torque rush. Gonna check the specific code tonight.
The specific code was p1516. Now the TB was not on the intake, just loose on the side of my current setup. That code is the same one that I was getting at full throttle with the BBK body. Any suggestions?

[PitchBlackC3]

Double check the adapter instructions where it talks about whether to cut the wire loops or not. IIRC it is do not cut for the 87mm truck TB which I think you said you are using.

[genXhunter]

I got everything installed and retuned for the larger intake and TB. It seemed to be fine until we started doing wot runs. Midway in 2nd gear it would shut down and flag a reduced engine power ses light. After reading online about this problem, it seems that some of the early GM truck TB's had weaker springs that allowed the blade to shut at full acceleration above 50mph. Also, they said that a newer truck TB should clear the problem. We tried my buddies TB off his brand new '10 truck and it did however, the part id on the front contained a 3C number and mine was a 3B model. One variable is that I had ported the front lip off of mine before putting it on and his is factory. Could that lip cause such a disruption in flow that would cause the flap to close and the 3B, 3C number mean nothing or is this a common problem? My intake comes off a trailblazer SS and does angle upward some possibly adding to the problem. My alternatives are to try another truck TB or get one from and LS3 (90mm). The difference in price is about $60. What do you guys think?

[foggy]

I had the same problem when I had one off of a tbss. I switched to a vette tb and no more problems.

[genXhunter]

I read about the same thing with another guy that was using a TBSS body but mine (was supposedly) pulled off a '08 truck which is why I was weary about trying another truck TB. I found an LS3 TB and ordered it. It should be here to install by Friday. I will let you know how that turns out. Overall though, the truck has TONS of upper mid range and top end with the larger 88mm setup. I am wondering how much that will translate to 1/4 improvement but we shall see next time I go.

[PitchBlackC3]

What did you adjust in your tune for the larger TB?
I am running a truck TB and it works fine. Mine has the 2001 TAC, but that shouldn't be an issue since you have the adapter.
Read up on the HP loss with the car TB before you go that route.

[genXhunter]

We really didn't have to adjust much in the tune. Just made minor adjustments to a/f ratio at wot. We double checked everything else and it was pretty close. The TB problem has been reported with the TBSS bodies and a couple off trucks up to '08 model year. It may have something to do with my intake angling upward some causing unusual airflow problems as opposed to a straight-in inlet. I have to get another body because this one closes at high airflow in second gear.
Searched this forum and have not found anything on power loss from using a car TB. Can you please guide me? I read some people have had success with them. I am gonna try it out and see if it clears up my problem. If it doesn't, I'll look into other options.

[PitchBlackC3]

I think all the intakes angle up like that. Mine does and it is from a 2008 5.3. Let me see if I can find a link to that car TB info. It is because the throttle blade opens in the opposite direction.