AFR Issues

[Don W.]

Re: AFR Issues

Well I do not see anything obvious with the eavp system. The vacuum line is hooked to the TB, the check valve is the right direction and works. The line to the tank is clear and holds pressure. I pull the cap off and the pressure relieves. The cap is vented and works one way(air is let in to the tank). The canister itself seems to be connected correctly. There is a 3rd port that has some sort of cap that is supposed to be vented and leaks a bunch of air? Probably where the heavy fuel smell was coming from. So Im guessing hot day, hot fuel coming back to the tank caused the system to over pressurize forcing excessive vapor into the evap system and back into the TB causing extreme rich condition?

The 3rd connection is plugged on my truck. Also there is a filter on the bottom which is how the canister gets "purged". IE eng vac sucks air through that filter, through the carbon in the canister and into the intake. The smaller of the two hoses.

The manual say to attempt to blow through the purge line (the small hose) and very little or no air will pass. (Apparently there is a check valve inside.)

Other than your open port which should plugged and checking that filter, you might have to just replace the thing.