[alchemist1]

Last evening, the 1991 Mustang began running rough, and when running, i was able to hear a vacuum leak. There was a hose at the base of the distributor that i found completely disconnected, at a connector barb. The connection was from an emmission hose going to underside of upper intake and a hose that went down to the charcoal canister. I was able to put a splice in and all is fine now. Thinking about the entire system, though, I'm wondering where the canister purge valve location is located?? Is it down near the charcoal canister??

Thanks,

RT

 

[ALMOST STK]

This should help.

 

[Travis98146]

It's good that you found the vacuum leak and repaired it. The on-board computers don't like vacuum leaks as they try to repair the lean mix by changing fuel supply and/or timing.

 

[wbrockstar]

Im surprised the car was even running period with that particular vacuum hose disconnected.I accidentally forgot to plug that hose back in one time and the engine would immediately stall as soon as I started it.The purge valve really needs to be put back in service if you're gonna leave that vacuum hose attached to the intake because if not,the fuel mixture will run rich at times when its not suppose to.Thats the reason why the purge valve was placed there.So that the ecm could open/close the valve as needed to either allow those vapors to flow or stop them.Most of the time if someone deletes the purge valve,they simply cap that vacuum port on the intake and leave the hose from the fuel tank vent valve open to atmosphere,but that causes you to smell gas fumes all of the time.So the previous owner either:
1) deleted the purge valve,left the vacuum hose open to atmosphere,then got tired of the fuel
odors,so he connected the hose straight to the intake instead.
2) deleted the purge valve then connected the vacuum hose straight to the intake.

Connecting the vent valve hose straight to the intake will indeed get rid of the fumes,but
unfortunately it also causes those fuel vapors to be constantly sucked into the intake instead of being regulated by the ecm & purge valve.These fumes will be treated as unmetered fuel that the computer wont be able to adjust for.Poor idle and poor fuel economy is usually the result.