Thick_Ryan

I'm to the smog portion of my swap. I've spoke with the California smog referee. He says I will need a EVAP canister on the fuel system/tank. I have a general idea of what a EVAP canister does but I dont know how its applied. Does anyone have any pictures and tips on how to hook it up to pass smog.

Also does anyone know of a header that is CARB legal and cost effective. I've been seeing them in the $500 range. I would like it uncoated in case it has to be modified to fit.

Any help would be great

bczee

iTrader: (12)

I would suggest you pull a Canister from the same model as the engine donner came from. As your Cert Smog test will be based on the new engine and require the same equipement. This is due to the ODBII sensor that you might be required to have in the Canister and Fuel sending unit. All of that has to be connected to your PCM for input. You might want to talk to the Referee again on what type of Canister and its requirement for your Gen III/IV engine (what 5.3l are you using... LM7, LM4, LH6, LY5,etc but not a LS1...?)

A little back ground on the EVAP Canister (ref Wikipedia):
All vehicles sold in the United States (since at least the 1980s, probably the 1970s or earlier) are required to have a fuel evaporative control system (called an EVAP system in automotive jargon) which collects expanding fuel vapor from the fuel tank in a charcoal-lined canister while the engine is stopped and then releases the collected vapors (through a "purge valve") into the engine intake for burning when the engine is running (usually only after it has reached normal operating temperature.) The fuel evaporative control system is also required to include a gasketed filling cap which seals the fueling inlet to prevent vapors from escaping directly from the tank through it. Modern vehicles with OBD-II emissions control systems will turn on the MIL (Malfunction Indicator Light, a.k.a. "check engine" light) if it is detected that the gas cap is missing or loose and so not sealing. (The general purpose of this light is to indicate when any of the emissions controls are not working properly.)

Thick_Ryan

Thank you, lots of help. I have a 5.3 LM7 with the iron block and aluminum heads. I would still like to see a picture of a setup that has been on a swap of a similar engine.

steveelco

bump same question as ryan also in california

l8apxes

I have many. Just getting started on researching an LSx into 91 Miata swap.
Being in CA, I know that requires full donor car smog equipment. The issue of evap canister and filler cap SES reporting has me worried. Swapping in the fuel tank is not an option. I have seen several miata conversion sites and so far they are all NOT in CA. So things like CATs and smog details are missing.

So bczee, I see you have done pre OBD-I swap. How did you deal with evap and filler cap issue?

Headers are another issue. Everyone seems to replace the OEM manifolds in this application so I'm guessing they don't fit. So headers for me have to be CARB legal.

Lots more reading to do I know. Any insights?
TIA
Dave

Steve VanS

iTrader: (1)

We used an EVAP can from a '99 Camaro in our swap. Note that a "full house" EVAP system is controlled by the PCM and will include:

The EVAP can
A purge valve that vents the can to the intake manifold
A vent valve on the can that allows air to vent into the tank with the engine running
A pressure sensor to tell the PCM to vent the can

The Camaro EVAP can has (3) fittings on it:

Vapor from the tank to the can
Vapor out to the intake manifold
Air vent

Get a GM factory service manual off of eBay for the donor vehicle of your engine. It will detail the wiring used to control the EVAP system. On our '99 Camaro harness, the EVAP wiring went thru GM connectors C220 and C230, and was simple to hook up. We put the pressure sensor in the vent line from the fuel tank to the EVAP can. The pressure sensor was removed from a Camaro in-tank fuel pump assy. We used a brass Tee fitting: hose barbs for the vapor vent line across the top of the Tee, and a brass NPT plug drilled out for the pressure sensor rubber seal, which was screwed into the stem of the Tee

bczee

iTrader: (12)

For my "pre-ODB-I" , 71 chevelle setup. i did away with the LS1 EVAP setup. I used the vacuum port to provide a vacuum source to the 71 Chevelle OEM Charcoal Canister... as it would normally function.. but i capped off the PCV port on the Canister.. so .. basically the vacuum source is just pulling the vapor out of the tank.

steveelco

i think im gonna try to mate 2 tanks to use the stock f-body pump in my tank has anybody done similar? it would solve alot of problems do i also have to use the filler neck and cap also?

bczee

iTrader: (12)

You could weld in a sender ring on top of your tank to accept the F-body sender and it sensors.

steveelco

yeah some where on here somebody put an f body pump in a g body tank and it looked nice i think im gonna try it