tenpaiyomi
July 27th, 2016, 06:04 AM
224R cam, stock heads, 6 speed, 5.7L
As the title states, my AC compressor keeps on cycling on and off, usually at about 1 second intervals. I've hooked up manifold gauges, static pressure on high/low is ~90psi. With the car running, it's about 30psi low/200-250psi high.
I've logged the pressure switch value and it goes between 200-250psi when the AC is cycling on and off and matches the manifold gauge values.
IAT reads 86*F which is about right for ambient temperature given I am in a shaded garage, so the pressure readings are about right for ambient temperature. I'm lost as to what could be causing the AC to cycle.
The thing that is more confusing is that, when I am driving, about 80% of the time it will do this cycle on/off scenario whenever I turn it on for a second to check, and the other 20% of the time it drives fine, only turning off every now and then as would be normal for AC systems.
To add, this is a brand new AC compressor (literally, I just got a new one the other day in the case that my old one was bad), brand new lines.
I've jumpered the trinary AC pressure switch and the compressor continues to cycle on/off. As well, if I turn the compressor on via EFILive then it will turn on and stay on, so that makes me believe that there is some sort of issue that the PCM is seeing. The only issue is....what? I've looked at the conditions for the compressor to turn on and stay on and, as far as I am aware, I meet them all.
The following conditions must be obtained before A/C compressor engagement is allowed:
* A/C Pressure is between 180 kPa (26 psi ) and 2900 kPa (420 psi ).
* Engine coolant temperature (ECT) is less than 121 *C (250 *F) .
* Engine RPM is more than 550 RPM .
* The A/C request signal circuit is grounded.
Once engaged, the compressor clutch will be disengaged for the following conditions:
* A/C Pressure is more than 2900 kPa (420 psi ).
* A/C Pressure is less than 180 kPa (26 psi ).
* ECT is more than 121 *C (250 *F) .
* Engine speed is more than 5,500 RPM .
* Throttle position is 100 percent .
* Transmission shift
* ECM detects excessive torque load.
* ECM detects insufficient idle quality.
* ECM detects a hard launch condition.
Any assistance is greatly appreciated, as it is consistently over 100*F here and I am dying.
As the title states, my AC compressor keeps on cycling on and off, usually at about 1 second intervals. I've hooked up manifold gauges, static pressure on high/low is ~90psi. With the car running, it's about 30psi low/200-250psi high.
I've logged the pressure switch value and it goes between 200-250psi when the AC is cycling on and off and matches the manifold gauge values.
IAT reads 86*F which is about right for ambient temperature given I am in a shaded garage, so the pressure readings are about right for ambient temperature. I'm lost as to what could be causing the AC to cycle.
The thing that is more confusing is that, when I am driving, about 80% of the time it will do this cycle on/off scenario whenever I turn it on for a second to check, and the other 20% of the time it drives fine, only turning off every now and then as would be normal for AC systems.
To add, this is a brand new AC compressor (literally, I just got a new one the other day in the case that my old one was bad), brand new lines.
I've jumpered the trinary AC pressure switch and the compressor continues to cycle on/off. As well, if I turn the compressor on via EFILive then it will turn on and stay on, so that makes me believe that there is some sort of issue that the PCM is seeing. The only issue is....what? I've looked at the conditions for the compressor to turn on and stay on and, as far as I am aware, I meet them all.
The following conditions must be obtained before A/C compressor engagement is allowed:
* A/C Pressure is between 180 kPa (26 psi ) and 2900 kPa (420 psi ).
* Engine coolant temperature (ECT) is less than 121 *C (250 *F) .
* Engine RPM is more than 550 RPM .
* The A/C request signal circuit is grounded.
Once engaged, the compressor clutch will be disengaged for the following conditions:
* A/C Pressure is more than 2900 kPa (420 psi ).
* A/C Pressure is less than 180 kPa (26 psi ).
* ECT is more than 121 *C (250 *F) .
* Engine speed is more than 5,500 RPM .
* Throttle position is 100 percent .
* Transmission shift
* ECM detects excessive torque load.
* ECM detects insufficient idle quality.
* ECM detects a hard launch condition.
Any assistance is greatly appreciated, as it is consistently over 100*F here and I am dying.