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View Full Version : Car surges with A/C on



Dale Puumala
07-01-2002, 12:44 AM
OK, well, I got some coolant into my A/C system and it actually blows cold air now. Woohoo!

Background: I bought the car at Thansgiving last year, guy said A/C didn't work. I haven't run the A/C once since then. The car had been sitting in his garage since the previous April (2001), so the A/C hasn't been run at least since before that.

Now, when the A/C is on, the car surges back and forth all the time while driving. It'll do it when driving slow in first gear or on the highway in 4th or 5th gear. It's way more noticeable in 1st gear, but that's just because the gearing is so low.

Anyway, what's causing it to surge continuously? I believe it's surging more often then the A/C is cycling, so it's not that.

Thoughts?

Thanks,
Dale

TbirdSCFan
07-02-2002, 03:03 AM
You know, I can feel mine cycling also. Kind of a occasional tug. I think its related to my pressure/charge level. In my case, I think whats happening is the pressure switch signals the compressor to stop and then in just about a second or 2, the pressure goes back up and the compressor kicks in again. I guess I could raise the pressure setting somewhat and see if that makes any difference; I'm concerned about evap freeze up if I lower it any more. This could be further aggravated by the charge level being a few ounces low. They charged with 32oz of 134 which is 80% of the 40oz of r12. I think (don't know) another ounce or 2 could be added.

Man, without guages, it becomes guess-work.
I'll try 1/4 turn on the pressure switch and see if it makes any difference on the quick cycling.

Did you retro fit to R134a?
I did, but I'm seriously considering removing it after this season and recharging with a blend known as Cooltop or GHG-X8. I'm not completely satisfied with 43 degree vent temps. Not quite cold enough for a Texas summer.