EFI and the Stock gas cap

[KdkGrizz]

Hey everyone, I am planning on updating my 82 Waggy with a Holley Sniper EFI, backed up by the Novak adapters in tank lec fuel pump. I was thinking about one of my early 2000's cars that used to have the occasional CEL come on, and it was most always the gas cap. So I know the fuel tank vents to the filler neck. But I currently run a stock old school AMC gas cap (Non Vented). My gut tells me that this has the potential for problems. I can find nothing on Holley's, FiTechs, or Novak's sites about this.

Anyone else thought about this, or experienced an issue?

Grizz

[tgreese]

The gas tank does not vent to the filler neck. You get a CEL when the filler neck leaks, not when it's sealed.

The tank vents to the vapor recovery system; ie the charcoal canister under the hood. This should work fine with your EFI without any changes. All you need to do is delete the carburetor bowl vent to the canister.

[babywag]

It's a non issue.
Only time you'd have potential for a problem is if you did not vent the tank adequately like with the vapor canister.

No aftermarket system(that I'm aware of) has standard monitors or codes like an OBDII compliant system.

[KdkGrizz]

It's a non issue.
Only time you'd have potential for a problem is if you did not vent the tank adequately like with the vapor canister.

No aftermarket system(that I'm aware of) has standard monitors or codes like an OBDII compliant system.

I wasn't worried about CEL. I was more worried about if it would affect my performance of the new system if the gas cap was not vented.

Unfortunately my canister is AWOL. It was removed before I inherited the Waggy. I currently have a differential style vent in the end of the vent hose.

[babywag]

Again a non issue, long as it is vented in some form or another.