Low Freon in sight glass.

 

Thanks for the additional followups, guys. I will take another look at the freon levels and the bubble test.
I had started a new post on trying to tweak the idle up just a bit; if I got another 100 rpm in idle / drive, the compressor wouldn't stop / start flashing the light; I've proven that in lots of drive and idle/park times.

The rpm sensor on the compressor was flagged as the problem for another poster, and I had about decided I had that same issue; but it tests the same (resistance wise) on the old and new compressor, so I think that's not it.

Perhaps I did the calculation wrong- but based on the numbers on the hood/engine print, it looked like we needed 2 cans of refrigerant.
I will double check that too, but feel free to tell me what the correct amount of refrigerant is.



Thanks again!

 

Do you think the High Pressure sensor is causing the System to cut out?

Lots of times people refill their system to the max when it is 90 degrees outside. When it gets to a 100 degrees, there is to much pressure in the system and the high pressure sensor cuts the compressor off. That's why it is important to follow an ambient temperature chart.

 

Daryl, Be tough to diagnose a pressure issue without a gauge set on it but yes, ambient is important, this just doesn't seem like a high or low pressure switch issue.
Since it runs fine and only cuts off when coming to a stop at idle.....it does lean towards the rpm issue even though the sensor tested same as the old compressor.
but it tests the same (resistance wise) on the old and new compressor
Could the sensor in the old compressor be bad?, so the testing of the new compressor matches the bad one? He's increased the idle by 100 rpm and compressor doesn't stop.

 

For closure; I was toying with relearning the throttle closed position (to have it be a tiny bit open instead) per the post upthread (thanks for that), but my ex-mechanic (official) neighbor came up with a simpler solution of shimming the pedal position just a hair, as though I had my foot on the pedal adding about 100 rpm by default. So now, the only time the RPMs drop enough to trigger the issue is on occasion switching into reverse... The simple fix of turning the ac off and then on works fine in those occasions.

With 2 oxygen sensors out (so the fuel mix is a little rich perhaps) and the gas pedal always a little engaged, my mpg over my last big road trip is still in the 20-21 range, the same as I used to recall.

The car feels a little more ready to roll with this fix, but almost like it got an attitude adjustment, so that's alright.

So- not a total fix of the issue, but given the age of the car and all, a pretty good solution.

Thanks all!