Okay really need some help with this.... I've got the wild vents. I've searched around and can't find anything to help! I cannot find my vacuum leak.

I've replaced two check valves so far. My cruise control and my 4wd both work flawlessly.

I saw that the vacuum reservoir could go bad and cause it, but couldn't find anything that said where it was or how to check it.

Any ideas on what it could be?
Any help is appreciated, I got a 1200 mile road trip coming up and would really like if my ac blew out the correct vents more than 30% of the time on the highway....

 

Vacuum reservoir is under the cowl, gotta pull the plastic grille on top of it to get to it. (windshield wiper linkage is in there too.)

 

Okay got the reservoir out and it's fine, any other ideas?

 

Chaffed line where it goes through the firewall (with the A/C lines) to the blend door actuator.

Carefully pull out the slack so you don't break the line and loose it inside (major work to recover it)... check for chaffing.
If there is a hole, cut the line and join it with some 1/8"ID rubber tube... tuck the rubber into the firewall opening to keep the plastic line off the firewall.

 

Already did that, except I wrapped it with electrical tape.

 

Have it smoke tested. One of your local shops should be able to do it. Is the plenum fixed?

 

I saw a way of checking the lines with carb cleaner, would I be able to do it that way?

Also, haven't checked the lines under the battery tray for damage yet, could my cruise still work if there is something wrong with that line?


And lastly, the plenum is not fixed. I have the Hughes kit and a 180 tstat sitting on the floor of my room, just haven't gotten install them yet.

 

Plenum is just a big vacuum leak. You may not solve your problem till you fix that. Although, one would think the check valves would address that issue. I still think your problem is after those. Maybe in the dash......

If your cruise works fine, then it is not likely to be the problem.

 

Okay just checked both of the check valves I replaced and one is faulty. So I'm guessing it's been faulty since I put it on, I'll have to replace that one and see what happens. Hoping that's it..

 

That will do it. Blow into them to check air flow is one way.