[CJLS1Z28]

Well I had a problem. As easy as the Lt2 intake is to install, car would not stay on. It stalled and wouldn't start. I put the lt1 intake back on and discovered my ls3 map extension from Michigan motorsports is crap. So before i put the lt2 intake back on I'd like to know if my placement of the barb for the brake booster is in the correct spot. thanks

[ToxicJon]

Yup perfect

[cmitchell17]

Originally Posted by CJLS1Z28

Well I had a problem. As easy as the Lt2 intake is to install, car would not stay on. It stalled and wouldn't start. I put the lt1 intake back on and discovered my ls3 map extension from Michigan motorsports is crap. So before i put the lt2 intake back on I'd like to know if my placement of the barb for the brake booster is in the correct spot. thanks

So I got my LT2 from GPI today as well and I didn't order their MAP harness extension since I bought one earlier from a link on the thread from I think Michigan Motorsports as well, and your right it is crap, or either they changed some connectors or suppliers around from GEN III/IV to GEN V. You can see I tried to grind on the Michigan Motorsports harness connector plug to try to get it to fit in but it still would not fit in:


I may just completely cut off the connector housing on the MM connector just to try to get by for now.

As for the connector you are showing that is for the brake booster connection? Did you have power brakes when you put on your LT2 manifold?

The only other air hose that needs to be connected up is the PCV hose, which I found out as well is not a "direct bolt on" with the LT2 manifold, we need an extension hose as the LT2 plug barb stick up and there is no way you can make the stock one reach:


Also if you have the rotofab (not sure how the stock air intake fits), with the throttle body pointed down at the angle it is, it makes the air tube really hard to fit up. I had to force mine on there at a weird angle.

Also did everyone remove the sound insulator pad thing? I removed mine but not sure you have to or not, I would rather keep it if I can since I think it may help with sound and injector noise, although without it now it still sounds the same as it did I think.

Sorry I didn't realize the question you were asking, yes it appears that the fitting is in the correct spot, although as long as your hose from the brake booster fits ok it seems like it wouldn't really matter? If its not running right and dying, maybe you just have a large vaccum leak and maybe did'nt get the manifold on right with all the bolts? although I think you would know that if it wasnt on and sealing.

[CJLS1Z28]

Originally Posted by cmitchell17

So I got my LT2 from GPI today as well and I didn't order their MAP harness extension since I bought one earlier from a link on the thread from I think Michigan Motorsports as well, and your right it is crap, or either they changed some connectors or suppliers around from GEN III/IV to GEN V. You can see I tried to grind on the Michigan Motorsports harness connector plug to try to get it to fit in but it still would not fit in:
Attachment 1043490

I may just completely cut off the connector housing on the MM connector just to try to get by for now.

As for the connector you are showing that is for the brake booster connection? Did you have power brakes when you put on your LT2 manifold?

The only other air hose that needs to be connected up is the PCV hose, which I found out as well is not a "direct bolt on" with the LT2 manifold, we need an extension hose as the LT2 plug barb stick up and there is no way you can make the stock one reach:
Attachment 1043491

Also if you have the rotofab (not sure how the stock air intake fits), with the throttle body pointed down at the angle it is, it makes the air tube really hard to fit up. I had to force mine on there at a weird angle.

Also did everyone remove the sound insulator pad thing? I removed mine but not sure you have to or not, I would rather keep it if I can since I think it may help with sound and injector noise, although without it now it still sounds the same as it did I think.

Sorry I didn't realize the question you were asking, yes it appears that the fitting is in the correct spot, although as long as your hose from the brake booster fits ok it seems like it wouldn't really matter? If its not running right and dying, maybe you just have a large vaccum leak and maybe did'nt get the manifold on right with all the bolts? although I think you would know that if it wasnt on and sealing.

Thanks for the reply. When i put my Lt2 intake on the car wouldn't idle long enough for me to move. Not to mention after 2 cranks it wouldn't start again. I got the michigan motorsports harness and mine has the right ends but its still crap. I thought it worked fine in my LS3 vette but then when I drove around my block i got a ses code. I'm sending it back.

The PCV line is easy. Just used 3/8 fuel line and cut the ends. It fits perfectly. Same on the brake booster line. You are correct it takes some real maneuvering to get the Rotofab to work on the lt2. Since i have to wait for a new harness i put the stock intake back on and no issues

[CJLS1Z28]

Originally Posted by ToxicJon

Yup perfect

Thanks i appreciate it

[cmitchell17]

Originally Posted by CJLS1Z28

Thanks for the reply. When i put my Lt2 intake on the car wouldn't idle long enough for me to move. Not to mention after 2 cranks it wouldn't start again. I got the michigan motorsports harness and mine has the right ends but its still crap. I thought it worked fine in my LS3 vette but then when I drove around my block i got a ses code. I'm sending it back.

The PCV line is easy. Just used 3/8 fuel line and cut the ends. It fits perfectly. Same on the brake booster line. You are correct it takes some real maneuvering to get the Rotofab to work on the lt2. Since i have to wait for a new harness i put the stock intake back on and no issues

Thanks, I hate to do it and mess up my stock wiring harness, especially since the map wires are built into the whole top harness that also has the injector wires so I am sure you can't just buy the MAP wires you would have to buy the whole thing and it would be a PITA to de-connect all of it and replace, but I am thinking of just splicing with some quick splice/scotchlock connectors the factory MAP harness to the MM extension.

[ToxicJon]

https://www.amazon.com/Extension-Man...9-b698e0b800f6
This is the extension you need it’s the ict billet one. I made the thread on how to make it all work.

[s346k]

i used the mm extension and it worked fine. the car had no issues starting up and driving like normal. wot was lazy for a few pulls but it's back to normal now. runs hard.

[cmitchell17]

Originally Posted by s346k

i used the mm extension and it worked fine. the car had no issues starting up and driving like normal. wot was lazy for a few pulls but it's back to normal now. runs hard.

I think they changed connectors at some point or something is going on. I ended up pulling the contacts out of the MM one and plugging just the contacts into the stock connector and wrapped them in electrical tape for now. I did order the other extension harness that someone posted, but for some reason I feel like I will have the exact same problem.

If you don't have a good MAP connection the ECM will considered it failed and revert to sort of limp mode and you won't get full throttle opening.