homemade87

I installed my ls2 from a 06 trailblazer ss into my already had swapped a 04 5.3 truck motor. I am going from a 8 pin to a 6 pin. I had did some research and thought I had it figures out. I had gotten the pin locations from a local dealership . When I power the switch I here it flip open and closed for a second for a test , but I cant get any throttle movement. I had swapped the tp wires with no result. Is there something I am doing wrong. Heard there may be a diffrence between the silver plate and brass plate tb's . If so what do I need to get this thing going. Is there another tb I can use with the 8 pin or 6 pin with the 4 bolt tb. I do not want to go smaller mm. I do have some upgrades . Any help would be appreciated.

superdave84

Not sure if I am right here....but I don't know if you can run an LS2 TB on a 5.3....at least not without a total wiring and programming overhaul. You need the proper pedal from an LS2 car (Corvette or GTO...I suppose the TBSS too). I think you will need the E40 computer also. Without the correct pedal and pigtails, there's no way your engine can understand what your pedal is doing.

homemade87

Thanks for the reply. I guess I will look for an aftermarket throttle body to see if anyone has one that will work with my set up. At this point I dont know what direction to go.

superdave84

Well don't get rid of it yet....I might be totally wrong. I just know that I have an LS2 and needed to buy he specific pedal for it....and I know most (if not all) 5.3s are not running an E40 computer.

-Siggi-

I think you need the X-Link interface to make it work.
http://www.torquerush.com/

homemade87

Thanks, This may be a good option.

Does anyone know if there is a truck throttle body that is a 8pin that has good flow to it. Something more than the 78mm . I do have cam , long tubes , cold air , tune and will run on 93 . I don't want to hurt it with a small throttle body. My intake is a 4 bolt but I don't mind using a 3 bolt adapter plate.

Also , could any of the 8pin tb be ported to get somewhere in the 85mm range or more. I have a 04 intake and throttle body now.

homemade87

After many hours of research apparently there is no Throttle body with a 8 pin in the 90mm range for my 04 system drive by wire. I did wind up using a 90mm tb from a car that had a gold blade. I had to get a x-link to make it work. It does work great. I just hope it has a good track record for not failing. Its not like you can get a new one at the parts store if you happen to be out of town and stuck on the side of the road if it fails.

Old Geezer

iTrader: (3)

Just my $.02...W/ the mods you list, I seriously doubt you will see much, if any, improvement in performance.

homemade87

Gm seemed to think on a stock TBSS 6.0 the engine needed to have a different intake and a 90mm (actually 87m) TB for that set up. I am adding a cam 581/591, 225/229 , long tube header , cai , 11.1 comp ratio with 93, and tuned . Why do you think the 78mm TB would support this. Why would I want to down size what gm put on these engines. I would expect to see improvements with the 90mm. With my upgrades over stock I can take advantage of the stock 90mm TB.

chuckd71

iTrader: (23)

Is a 90mm tb necessary?

homemade87

Is it necessary, No. Will it run on a 78mm yes. Will it run to it potential, No.

oldgoat69

I found this pinout doing a search on the site. I am doing a similar upgrade, 8 pin to 6 pin 4 bolt TB from and LS3.
PIN A = Brown
PIN B = Yellow
PIN C = Black/white
PIN D = Green
PIN E = Lt blue/Blk
PIN F = Purple

I am using an LS2 / E40 PCM repinned to the truck harness. So far this is how I am making it work.

oldgoat69

Oops, forgot to mention that you will most likely need to use a TBSS pedal assembly.

homemade87

Old goat, I did try that pin out with no success. What years are you working from. Mine harness and pcm was from a 04 8 pin truck and I was using an 06 6 pin throttle body from a tbss. My under standing is that gm did away with the tack module in 04 or 05. Newer than this the pcm controled the TB, not a tack module. They just wont communicate. Thats why the need for the x-link from torqe rush so they can talk to each other.

I had a 5.3 in the truck for a couple years, thats why I have a 04 harness and pcm. I decided to put this 6.0 from a tbss in and this is why I have a miss match. So I do not have any of the tbss harness and pcm. I would have to change the harness out and I have a custom harness to fit my 82 c10. That why I was trying to make this work. It all works good now with the x-link. Just cost a lot more dollars to do it this way but I did not have much choice.

Old Geezer

iTrader: (3)

Go for it.........

homemade87

I hope not all of your 4000 + post are not this informative.

oldgoat69

So you are using a GMT800 PCM? If so this will never work. I can prove this having tried to make it work. You will need to go to an E40 PCM and T42 TCM if it is an automatic. I am in the process of posting the conversion table for repinning the truck harness for use with this combination.

Jones'n

Or just run the X-link module as mentioned before.

Johnny deere

I’m doing the same thing swapping intake and tb on lm7. So I’ve done my research and the best thing I come up with is x link. But my idea is gutting the ls2 tb and rebuilding with the stock 5.3 innards any input on that from anyone,,sucks xlink has the lock on this part,any input would help.

Project GatTagO

iTrader: (7)

Why not use the Trailblazer TB? They are 87mm.

Andrew