seen that valve just didn't know what it was for. will look into it. it should work in one direction right? if it doesn't hold on the back side i guess that would be an indication. could be why the enginehas a tad idle miss. like carburator would out of adjustment. course mine is fuel injected. but a small vacumn leak will cause that. it isn't very much but you can feel it in drive with brake on at a traffic light. will let you know what i find on that valve. thanks

 

I believe your mode actuator is vacuum controlled and if it is, either there is a vacuum supply leak or the actuator is leaking. You'll have to gain access to the vacuum harness to test for supply vacuum. Should have at least 17 to 19 " of vacuum supply, if not then there is a cracked plastic vacuum line.

 

i'll look into that. i see that you are a certified mech. right now i have a more serious problem, if you look at my other thread. i talk about battery drain. i did a test with a volt meter, between the negative cable and neg. post. it is drawing more than it should a normal draw is anywhere between 24-27 mil.amps. for the computer.i'm getting around 33. i pulled the 20amp fuse for the interior lights and it dropped to a normal draw. after pulling all fusesone at a time that was the only one that showed a large draw. the fuse gives current to all lights in side that includes dash, and dome, and courtesy. my question to you is i'm sure there is a timer type relay or some thing under the dash that controlls the current. when i open the door the courtesy lights come on and when i shut the door they go off after a few seconds as normal. also when i turn the key to start the engine. my theory is that there is a relay stuck in the closed position. the timer seems to be working normal. i have pulled the 20 amp fuse charging the battery and i will let the car stand for another day and then check the voltage to see if it drops. have you ever come across this thanks for any info this has been a thorn under my saddle[&:]

 

The 20a fuse is not the charge side of the alternator. Disconnect the big red wire from the back of the alternator as there is no fuse to control that. That will tell you if your internal voltage regulator is shorted pulling power away from the battery.

 

it's the second new alternator in a row, but i will try it after i try the fuse thing on the light theory thank you.

 

I am reasonably sure your car ahs vacuum operated air flow controls and an electric temperature door. It blows out the defrost when there is no vacuum, There is a vacuum connection to the intake manifold with a one way check valve under the hood that connects to the heater control head. I would check that first. If the one way valve is bad it will let it go to defrost when it is turned off, , or if there is a vacuum leak anywhere in the system, it will also go to defrost when you turn it off. You probably need to obtain a hand vacuum pump and start applying vacuum to the various components one at a time until you find the one that is leaking. There should be a connector at the back of the heater control head with half a dozen vacuum hoses that allneed to bne checked

 

I have a '96 CE with the same problem, although I have ATC. My cruise control also does not work, so I am pretty sure it a vacuum leak....SOMEWHERE ?? I put in a new vacuum bladder (the little ball just in front of the left front tire) which was not connected due to a broken nibble, unfortunatley this didn't help anything. Any help would be greatly appreciated, as I can't seem to pinpoint the leak.

 

I have a 94 and my dash vents do not get air either, just stopped a couple months ago. Am trying to find resolution also. All air controls work fine but nothing thru dash vents. I used to hear the vent close or open, but nothing now. I am thinking vacumn also

 

This may be the source of the problem?

http://forums.corvetteforum.com/c4-g...ac-access.html

 

Found a fix for dash vent not opening. Pop off the plastic protector on the passenger side of the engine, you will see a vacumn line with 2 outputs, one is for dash vent the other for cruise control. My plastic piece was broke and was able to use black tape to temporarly repair the part until I can get a replacement for the 3 way vacumn connection. Would think this would be the second thing I would check after checking the fuse by the passenger door.