Hey guys, the air in Bessie blows pretty cold for a 38 year old I6 200ci Maverick. But my problem/question is this: When I have to get on the gas, the air "goes away", that is you can still hear it but it doesn't blow through the vents. I'm not sure where is goes, it's not the floor, maybe the defroster vent. Anyway, it has to be actuated by vacuum, so maybe I have a vacuum hose in the engine compartment in the wrong place? Ideas? Thanks, CommieHook
Is your vacuum canister hooked up? Check valve working? When your engine loses vacuum the HVAC door(s) return to their non-vacuum state. The vacuum cannister isn't installed on mine and when the engine is under load I think outside air comes thru the dash vents. Yes, you should check all the vacuum line routing.
The defroster vent is the default path.. If you lose vac, it all goes there. One possible reason is a bad check valve or a leak in your vacuum reservoir (the coffee can on the passenger fender by the firewall). Sure this sits un-answered until I post a reply and then mine comes in last.
As stated....you don't lose your air. It is just redirected to the defrost mode. Same thing happens to my 4-door.
I had this on mine. It will also cause a rough idle! The can looked perfect, but I did a vacuum test on it and sure enough, it leaked! I took it off and just hooked the two hoses together, so my ac does what yours does when I put a hard load on the engine. Since I don't do that very often, my ac works well so I've not bothered to replace the can. By the way, the bottom of the can had cracked around the edge. I'm going to guess metal fatigue from pressurizing to evacuating constantly!
Um, I don't have the "coffee" can under the hood, but I do know what you're talking about....is this a problem? CommieHook
Without the reservoir, it would do exactly what you described, as it doesn't have a reserve of vacuum for those low-vacuum situations. I ordered a generic plastic one from Rockauto rather than finding one from a junkyard. It was about $10.
http://www.autozone.com/autozone/ca...39-10&displayName=Check+Valve.+Universal+Type You can also get them with a small reservoir built into them. USe to do them everyday on older Chryslers. They had a TSB for flipping to defrost with a one way valve/reservoir upgrade. Works great. 4677204 was the part number.
