1999 LS1 Evap System

[Restorod57]

I'm restomodding a 1957 Corvette. It has C4 chassis and '99 LS1 with a Tremec T-56. The fuel tank is a modified stock piece that includes separate installs of the sender and pump. Pump is a Walbro GSS340. The tank also has a 1/8" vent tube welded in.

My ECM is GM# 12200411, and I have been told this was used on 2002 Corvettes, Camaros, and trucks. The ECM will be re-flashed to exclude the post-cat O2 sensors.

Instead of just routing a vent hose out the back of the car, I want to install the C5 evap system. My LS1 already has the purge solenoid, but nothing else.

I know I need the cannister, but the other parts I'm not too sure of. Maybe a cannister vent solenoid? Do I also need the purge pipe that connects the purge solenoid to the hard line? This pipe has a service port. Also, does the gas cap also need to be vented?

Any help on these questions, and any GM part numbers, is appreciated. And, if I'm going about this all wrong, please advise me. Thanks, I'm really glad I found this site (it should help when my project is ready to be fired up).

[c4c5specialist]

HI there,

Truthfully, you should be able to take the canister and the vent solenoid off the Camaro or Corvette. But there are a few questions I would be concerned with.

#1, the evap system diagnostics requires the fuel level sensor input to accurately perform the system tests. You will need that. Voltage varies from .50 at empty, to 4.5 at full

#2, the Corvette used 2 sensors, but the Camaro 1, so the best choice would be a Camaro ECU and programming.

#3, Vacu-tite does make some hard plastic line kits that are similar to the OEM lines, that may be an option when running the actual hoses from the engine to the tank.

If there are any other questions, let us know.

Allthebest, c4c5

[ToolGuy]

Welcome to the site!

You have to post some pics of this car, it sounds like it will be really cool!

[Restorod57]

Thanks c4c5. I read where fuel level input was needed. I'm also wondering about the fuel tank pressure sensor - is that the sensor you're talking about?

Also - is it correct that the LS1 does not need the fuel Evap operational?

Toolguy: I have some pics posted in an album here. It should be open to public viewing. I have alot more to post.

I'm writing a book for novice builders on how to restomod the early Corvette. Most all of the chassis chapters are completed. My website has more info.

Thanks for the help!

[ToolGuy]

Yeah yes, found the pics! Pretty cool stuff!