|
|
AC goes warm on acceleration
#1609229
04/19/14 01:14 AM
04/19/14 01:14 AM
|
Joined: Sep 2013
Posts: 464
KY
Telvis
OP
mopar
|
OP
mopar
Joined: Sep 2013
Posts: 464
KY
|
I have a 73 challenger and recently rebuilt my heater box with a Detroit Gasket kit and installed a compact compressor and updated AC kit from Bouchillon Performance. Everything works fine except my AC goes warm when I accelerate. Noting changes as far as where the air blows. It comes out of the dash as it should. The heater diverter valve is working properly. The weird thing is the driver vent air stays cold. The warm air comes from the ash vents on the passenger side. When I lower the RPMs the temperature gradually cools down and goes back to cold. I am assuming it has something to do with the vacuum to the heater box. If I change the settings everything changes as it should. I know the lines are all connected correctly. I installed a one way check valve where the main line connects to the engine. I thought that might help retain vacuum if the motor lost vacuum during acceleration. It didn't help. Any ideas?
That's King Weenie to you!
|
|
|
Re: AC goes warm on acceleration
[Re: Telvis]
#1609230
04/19/14 07:18 AM
04/19/14 07:18 AM
|
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
|
You'd sure think if the one way check valve was properly retaining the vacuum that you'd be good since the only thing that is changing IS the lack of vac when you accellerate. I'd give Bouchillon a call. EDIT I wonder if you have a leak in the vac line/vac operated valve/switch (whatever it is) downstream from the check valve & without the constant vac from the eng when it gets capped off (with the check valve) that it simply bleeds out? I'd pump it up with a hand held vac pump (they're reasonable & a necessity for dist modding)
Last edited by RapidRobert; 04/19/14 07:26 AM.
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: AC goes warm on acceleration
[Re: 63stabamatic]
#1609232
04/19/14 08:36 AM
04/19/14 08:36 AM
|
Joined: Feb 2003
Posts: 8,020
Pangaea
B5 Bee
master
|
master
Joined: Feb 2003
Posts: 8,020
Pangaea
|
Quote:
Just a thought. Is it possible your A/C compressor is turning off when you accelerate? The reason I'm asking is I remember years ago some Mopars, mainly slant 6, and others turn off the compressors during hard acceleration for more power, especially passing and hills.
Don't know about the slant sixes deactivating the AC but the 440 cop cars did when in pursuit mode.
|
|
|
Re: AC goes warm on acceleration
[Re: B5 Bee]
#1609233
04/19/14 09:58 AM
04/19/14 09:58 AM
|
Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
70Cuda383
Too Many Posts
|
Too Many Posts
Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
|
I would be inclined to think that you have a vacuum leak that is causing the blend doors to move when you go WOT and lose manifold vacuum.
If your AC is hooked up on switched power and relays with line pressure switches (i.e. totally isolated from the engine) then it has no way of knowing when you go WOT and shutting off the compressor.
**Photobucket sucks**
|
|
|
Re: AC goes warm on acceleration
[Re: 70Cuda383]
#1609234
04/19/14 11:07 AM
04/19/14 11:07 AM
|
Joined: Jul 2007
Posts: 1,526
North Carolina
cjskotni
pro stock
|
pro stock
Joined: Jul 2007
Posts: 1,526
North Carolina
|
Quote:
I would be inclined to think that you have a vacuum leak that is causing the blend doors to move when you go WOT and lose manifold vacuum.
If your AC is hooked up on switched power and relays with line pressure switches (i.e. totally isolated from the engine) then it has no way of knowing when you go WOT and shutting off the compressor.
 The HVAC system on these cars has no connection what so ever to the engine besides the vacuum on the blend doors. The only way the compressor can shut off (in A/C mode) is with a low pressure situation from the drier sensor which will break the clutch circuit if the pressure drops to save the compressor from damage.
Replace the check valve on the vacuum harness. They have them in the HELP section at Advance Auto and similar chain stores. The next thing would be the vacuum servos themselves which could have a slightly torn diaphragm causing it to leak down prematurely and close the bend doors the moment vacuum drops.
You can also test this theory if you pump the brakes (if power) repeatedly and listen/feel for the doors to close while the A/C is on. This will have a similar effect to WOT on the vacuum.
Good luck but don't overthink this! 
|
|
|
Re: AC goes warm on acceleration
[Re: Telvis]
#1609236
04/19/14 06:36 PM
04/19/14 06:36 PM
|
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
|
if the blower motor is recieving full 12V on high then I think a modern motor that spins at a higher RPM would be the solution. shouldn't be too hard to find one of the right dimentions & swap the round vane piece onto the shaft with a setscrew. I'd think it'd be just like a box fan in your shop. the faster it turns the blades the more air it kicks out
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: AC goes warm on acceleration
[Re: Telvis]
#1609238
04/19/14 11:49 PM
04/19/14 11:49 PM
|
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
|
Part time problems are the cats' ass
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: AC goes warm on acceleration
[Re: RapidRobert]
#1609239
04/20/14 10:33 AM
04/20/14 10:33 AM
|
Joined: Jan 2003
Posts: 21,072
Niles , Ohio
therocks
oh wait.but hey.lets see.oh yeah.
|
oh wait.but hey.lets see.oh yeah.
Joined: Jan 2003
Posts: 21,072
Niles , Ohio
|
Most had a vacuum resevoir.It retaind vacuum on heavy accel so the unit had vacuum.There should be one somewhere.Make sure its holding vacuum if you have one.Most were round plastic some like Fords actually had a tin can that was painted.Rocky
Chrysler Firepower
|
|
|
Re: AC goes warm on acceleration
[Re: therocks]
#1609240
04/20/14 12:06 PM
04/20/14 12:06 PM
|
Joined: Sep 2013
Posts: 464
KY
Telvis
OP
mopar
|
OP
mopar
Joined: Sep 2013
Posts: 464
KY
|
I don't think the E bodies had them. I had a 68 Charger that had the canisters. I thought that was for the headlight covers. If my Challenger has one it's hidden somewhere inaccessible because I have had everything apart at one point or another.
That's King Weenie to you!
|
|
|
Re: AC goes warm on acceleration
[Re: moretoys]
#1609242
04/20/14 04:43 PM
04/20/14 04:43 PM
|
Joined: Jul 2007
Posts: 1,526
North Carolina
cjskotni
pro stock
|
pro stock
Joined: Jul 2007
Posts: 1,526
North Carolina
|
Quote:
isn't the temperature door,cable operated? the vacuum controls the mode,direction of the air flow. the system could be undercharged or overcharged. (ambient temp will cause this to do different things)The system should also shut off too prevent freeze-up. There would be a switch on the carb if it is equipped with a.c. throttle cut out switch.or could have a switch inline with a vacuum line.
I am not sure about the 73 E-bodies but the 71-74 B-bodies, all the doors inside the HVAC box are vacuum actuated. The only thing that is cable operated on the 73/74 B-body is the heater valve inside the engine compartment. Earlier years are vacuum here as well.
If he is running the original compressor, they had a valve (big honken canister looking thing) on the AC lines that would serve the purpose of not allowing the evaporator to freeze up. If you go to a Sanden compressor, you will need a separate thermal switch to do this.
With a factory 73 B-body setup, the only thing (besides turning it off) that can cycle the compressor is the low pressure switch on the drier. If you look at the wiring diagram, the AC compressor circuit comes from the HVAC controls to the low pressure switch then directly to the compressor. There is no connection whatsoever to the accel linkage or carb. I can't imagine the E-body would be any different.
Trace that blue compressor wire....I bet you will see it goes to the low pressure switch on the drier and then goes with the engine harness back to the firewall bulkhead connector. From there, it's straight to the HVAC head unit. Not anything else that should break this circuit....
Also FWIW, 73 B-body didn't get any vacuum canister I'm aware of. I know mine never had one. Maybe somebody can chime in but I am thinking the E-body would be pretty much the same. These engines from the factory pulled plenty of vacuum on their own in 73...
|
|
|
Re: AC goes warm on acceleration
[Re: cjskotni]
#1609243
04/20/14 11:05 PM
04/20/14 11:05 PM
|
Joined: Sep 2013
Posts: 464
KY
Telvis
OP
mopar
|
OP
mopar
Joined: Sep 2013
Posts: 464
KY
|
The AC system is working properly. I converted to a sander system from Buchillon Performance. The issue is in the heater box. It is vacuum controlled for all doors. The only cable runs to the heater diverter valve and is operating properly. I swapped out the one way valve for the vacuum under the dash. Drove it a bunch today and it about froze me out. I think I am good at the moment. FYI... There's no AC cutoff at the throttle.
That's King Weenie to you!
|
|
|
|
|
|
|
