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Discussion Starter #1
A/C CUTTING OFF WHEN GAS PEDDLE PUSHED "
AND THEN RETURNS WHEN AT LOW RPMS ?
97 4.6 LX
NEW COMPRESSOR--NEW LINES ETC "
HELP !
 

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1997 Thunderbird 4.6, 1998 Mark VIII LSC
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The A/C is supposed to cut out at WOT (in reality about 60-70% or so or more throttle). May be worth testing the TPS - though if the TPS was that far out of spec you'd also notice shifting issues. In any case it should be a touch under 1V at idle and smoothly (no dips or spikes) advance to at least 4.5V with the throttle wide open.

Otherwise - refrigerant charge OK? If it's a little low it will give the impression of working at lower RPM/temperatures but start to cycle frequently when the compressor/engine runs a little faster.
 

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Discussion Starter #3
The A/C is supposed to cut out at WOT (in reality about 60-70% or so or more throttle). May be worth testing the TPS - though if the TPS was that far out of spec you'd also notice shifting issues. In any case it should be a touch under 1V at idle and smoothly (no dips or spikes) advance to at least 4.5V with the throttle wide open.

Otherwise - refrigerant charge OK? If it's a little low it will give the impression of working at lower RPM/temperatures but start to cycle frequently when the compressor/engine runs a little faster.
*
NO Shift issues at all !
I had a local shop replace the compressor--lines etc:
its never done this stuff before the replacement !
Like i said A/c works cold at normal start out-
but cuts off --[ blower still blows but hot ! }
then up to 45 mph it will blow cold
but after that it gets hot air only ?
 

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How long ago was the replacement, and why did you need to replace those components if it worked fine before ?

You would need to run a diagnostics test by monitoring the compressor cycling rates and comparing the air temp vs. Outside temp charts with the engine at 1500 rpm for 10-15 minutes with a manifold gauge setup on the high / low side. If its cycling too rapidly the cycling switch (pressure switch) is bad. You can bypass the switch with a jumper and check to see if the evaporator inlet and outlet are different temperatures. If not it could be the a/c heater switch or the CCRM has a bad relay.
 

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Discussion Starter #5
COMPRESSOR DIED --SO ALL LINES WERE REPLACED -- COMPRESSOR REPLACED --MONTH OR SO BACK !
THK YOU I WILL HAVE THEM LOOK AT YOUR SUGGESTIONS !

AT IDLE THE A/C CYCLES NORMALLY --JUST SAYIN !
 

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i would have to make the following assumptions first - that the shop who serviced your AC is qualified and understands how to properly service your system and has added the correct amount of refrigerant to the system. If the shop followed the standard evacuation and recharging procedures, they should be able to diagnose and repair your system without my suggestions.
 

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A/C CUTTING OFF WHEN GAS PEDDLE PUSHED "
AND THEN RETURNS WHEN AT LOW RPMS ?
97 4.6 LX
NEW COMPRESSOR--NEW LINES ETC "
HELP !

COMPRESSOR DIED --SO ALL LINES WERE REPLACED -- COMPRESSOR REPLACED --MONTH OR SO BACK !
THK YOU I WILL HAVE THEM LOOK AT YOUR SUGGESTIONS !

AT IDLE THE A/C CYCLES NORMALLY --JUST SAYIN !
Turn the caps lock off. It's the key to the left of "A" on your keyboard. Just sayin'. We'll help you figure this out. No need to shout.
 

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If it suddenly changes from cold to hot on hard acceleration, then that is not a problem with the AC. If the AC cuts out, it still takes a while for the evaporator to warm up, so it will gradually change to warm as you keep your foot in it, and short of doing a top speed run, you’ll never notice it. Your issue is a vacuum leak problem. The blend door actuator is vacuum controlled, and if it loses vacuum signal, it defaults to heat.
 
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Discussion Starter #9 (Edited by Moderator)
i would have to make the following assumptions first - that the shop who serviced your AC is qualified and understands how to properly service your system and has added the correct amount of refrigerant to the system. If the shop followed the standard evacuation and recharging procedures, they should be able to diagnose and repair your system without my suggestions.
****
Well-- local shop-- so I did-- not-- Question their qualifications !
hi and sight should have-- !
But it is what it is now !
Pressure switch seems to be the popular assumption at this point !
I did take the car back to that shop-they drained off some 134 a- but still no JOY !
39304
 

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1997 Thunderbird 4.6, 1998 Mark VIII LSC
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If the AC cuts out, it still takes a while for the evaporator to warm up, so it will gradually change to warm as you keep your foot in it, and short of doing a top speed run, you’ll never notice it.
My cars are clearly not as fast as yours are. :)

I notice when the A/C relay goes into WOT cutout mode 5-8 seconds or so in. Because it then takes a few seconds of normal PT operation for WOT cutout to disengage and for the evaporator to chill again, it's usually about 10-15 seconds of "A/C feels off" when I experience it. It's certainly not a sudden change as you said but it is pretty noticeable by me (usually I first notice the humidity, then the temperature change).
 

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They removed some refrigerant? Does this mean they overfilled it to begin with? That would make me question the work they did.
 

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Discussion Starter #14
Yes they removed some !
And at this point I am questioning the total job !
AZ is too damn Hot to have the A/c issues !
 

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39341


This is what a slipping belt looks like. My co-worker pulled the company F150 truck into the parking lot making noise and stinking. This AC completely froze up.

The first step to diagnose your AC issue is to ensure it has a proper charge and put a set of gauges on it to watch what the high / low side are doing.
 

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Clutch/compressor froze on my truck a couple weeks ago. 800 bucks down the drain. I had just replaced the condenser this spring which was another 800. 5 year old truck shouldn't need all that.

I was more implying a tensioner was possibly weak in this case.
 
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