ls3
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Heel & Toe
Joined: Jun 2014
Posts: 20
Likes: 0
ls3
I have the ls 376/525swap . various people have helped me before from here and the Facebook pages but I still can't seem to get it running right . I get all these codes that pop up saying reduced engine power but the engine it self has no codes . I was told,to change my tb to a ls2 tb. Because the ls3 doesn't communicate with the pcm. So I bought that and it's to small and doesn't even bolt up . and than they told me to check my tac control module for corrosion . any thing else I should look into ?
Racer
Joined: Oct 2004
Posts: 370
Likes: 1
From: Tracy CA
I have an LS2 throttle body (silver blade TB is what you need) on my LS3 intake and it fits perfect...both are 90mm.
LS2 TB-
-Rick
LS3 427/615
Last edited by Switchbarrel; Dec 6, 2014 at 12:00 PM.
Burning Brakes
Joined: Aug 2006
Posts: 956
Likes: 12
From: Eastern PA
I have the ls 376/525swap . various people have helped me before from here and the Facebook pages but I still can't seem to get it running right . I get all these codes that pop up saying reduced engine power but the engine it self has no codes . I was told,to change my tb to a ls2 tb. Because the ls3 doesn't communicate with the pcm. So I bought that and it's to small and doesn't even bolt up . and than they told me to check my tac control module for corrosion . any thing else I should look into ?
Here is a couple threads which may help:
https://www.corvetteforum.com/forums...-problems.html
https://www.corvetteforum.com/forums...ttle-body.html
https://www.corvetteforum.com/forums...ttle-body.html
Burning Brakes
Joined: Jan 2009
Posts: 939
Likes: 52
From: The Woodlands Texas
Don't know how you got the LS3 throttle body to work in a C5. It opens 180deg different from the LS1/2/6 units. Not sure about the LS7. As said, this prevents it from communicating correctly with the computer. It works fine until you go past 30% throttle at which point in puts you in reduced power mode. You can reset everything and drive fine until that 30% input threshold is hit and it happens again. Changed mine out to a LS2 unit as advised by LPE and everything works fine.
Burning Brakes
Joined: Jan 2009
Posts: 939
Likes: 52
From: The Woodlands Texas
To the OP, I have the LS3 480 setup (instead of the 525 you have) and did not have a bunch of codes. Do you have then upon start up after clearing them or just when you go for a drive and hit the threshold that sets them off? If its the later change the throttle body and all will be good. I had no codes at idle, cruising slow around the neighborhood but got on the main road and pow, reduced power mod.
Burning Brakes
Joined: Aug 2006
Posts: 956
Likes: 12
From: Eastern PA
Don't know how you got the LS3 throttle body to work in a C5. It opens 180deg different from the LS1/2/6 units. Not sure about the LS7. As said, this prevents it from communicating correctly with the computer. It works fine until you go past 30% throttle at which point in puts you in reduced power mode. You can reset everything and drive fine until that 30% input threshold is hit and it happens again. Changed mine out to a LS2 unit as advised by LPE and everything works fine.
