Removing EPR Valves when Converting Your Mopar to 134a | Classic Auto Air - Air Conditioning & Heating for 70’s & Older Cars & Trucks. found this for you . Makes sense . havent heard your noise so I really don't know what you are chasing ,if it's light then perhaps this valve is cycling rapidly...
And as I previously said I've seen compressors in my career that make noise at different speeds whether it be idle or higher Rpms . The methods I described previously will detect a low side starvation problem ... Gauges will show this along with temp readings along the suction pipe from EVAP to...
I pm d you bro to send me the vid of this noise. Btw you said this compressor was built for 134a but you swapped a r12 EPR probably not the best idea but ... Hey if you think it's the EPR starving the compressor just run it without it and check bro. It's certainly not going to hurt anything to...
Unfortunately I don't have a yahoo account my friend. Video link immediately asks for login. You could run the compressor BRIEFLY with no charge since there is always oil in the compressor . But what will that determine ? If the noise goes away .... Ok ..there is no gas load on the compressor...
Was the engine surging at idle ? Like rpm hunting ..... Or are you saying it surged at cruise ? Like you physically feel an extra load coming and going while at speed ( as if you were lightly applying brakes or like when an air conditioner kicks on and off on a smaller engine)???
EPR valve EVAP PRESSURE REGULATOR . OK well was the nylon screen filter visible ? When u swapped? Although any restriction at this valve should show in temps and pressures . Looks like you short charged it properly to compensate for 134a , pressures look fine .(should correspond to about 38...
EVAP PRESSURE REGULATOR valve ... Ok . There should be a screen on those made of nylon to protect compressor at the suc inlet from any debris in system . Was that visible with any restrictions or perhaps torn / degraded so basically open ? Although you seemed to have short charged it correctly...