yes i have a 95 ranger 4.0 5speed. my problem is that is has been running rich and has had a rough idle and seepage has been comingo out of a splice in a fuel vapor line right behind the fuel filter "differnt line" A while back i put it on a scanner and it said something about a low reading on a vacum purge valve of some sort i erased it and it never popped back up. well it has been running rough for about two months or so when at idle. It runs like a scalded dog any other time. Well to day i was checking over my vacuum lines and some rubber lines on the drivers side were dry rotted. Ones going into the vapor canister or box i guess you would say and before hte box was a electric valve or module and the line before that was rotten, i think because they hold up the valve's weight. Well I was trying to unhook the hose going into the valve and its tube that the rubber hose goes over broke off. the hose that went into the valve came out of another electric thing and on back went into the upper intake right around the air inlet. I plugged the hole with my finger and the ole 4.0 ran like brand new nice clean idle. i couldn't rig the piece i broke to work and couldn't find one at parts store so i just plugged the hose and drove it with no problems. my question is would it hurt anything to just run it like that. i know you can plug any vacuum leak on older cars but this fuel injection and electronic stuff has me wondering. it didn't pop up the check engine light. my only concern would be the electric vale which i broke. it has a rubber cover around it and it connects to the vapor box. would it hurt anything to just let dangle there with no pressure going into it.

 

If you leave it unhooked, you could get sick of smelling gas fumes. Seriously, it may or may not hurt anything, but it can't be good for it, especially for smog reasons.

 

The thing you broke is the cannister purge valve (cannister purge solenoid).

The PCM is programmed to slightly shorten fuel injector pulse times when it thinks the valve is open and fuel vapors are flowing into the upper intake mixing in with the a/f charge. This is done to maintain proper a/f ratio.

I have to assume that sooner or later you will get another CEL.

Probably is best performance and emissions-wise to put a new purge valve on there and replace those worn hoses while you are at it.