GnatGoSplat Posted April 5, 2005 Report Share Posted April 5, 2005 94 Cutlass A/C gets uncomfortably warm when idling or driving slow. I noticed the FAN2 isn't running. I think it's supposed to run all the time, but for some reason, it isn't. To make sure the PCM isn't the problem, I've checked and it's reporting FAN2 isn't being requested. The service manual says FAN2 comes on with A/C on, car under 40mph, and A/C Pressure sensor reading of 240psi or higher. The PCM is reporting AC Pressure is 125psi. Can lack of freon cause A/C Pressure to read too low? Quote Link to comment Share on other sites More sharing options...
1990lumina Posted April 5, 2005 Report Share Posted April 5, 2005 I'd say it *could* cause a low pressure situation. I just think about when your car is a little low on engine oil, and the oil pressure goes down a little. Quote Link to comment Share on other sites More sharing options...
5speedz34 Posted April 5, 2005 Report Share Posted April 5, 2005 Yeah, I would think the same thing that since there is less freon there is less pressure being able to be disperssed. Do you know if the car is low on freon or what? Quote Link to comment Share on other sites More sharing options...
DiscoStudd Posted April 5, 2005 Report Share Posted April 5, 2005 I know that 94 was the transition year to R-134a, but does your Cutty have it or does it have R-12? If it has 134a, you can pick up a "recharge" can at Wally World that has a pressure gauge attached to the fill hose and go from there... Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted April 5, 2005 Report Share Posted April 5, 2005 94 Cutlass A/C gets uncomfortably warm when idling or driving slow. I noticed the FAN2 isn't running. I think it's supposed to run all the time, but for some reason, it isn't. To make sure the PCM isn't the problem, I've checked and it's reporting FAN2 isn't being requested. The service manual says FAN2 comes on with A/C on, car under 40mph, and A/C Pressure sensor reading of 240psi or higher. The PCM is reporting AC Pressure is 125psi. Can lack of freon cause A/C Pressure to read too low? A lack of freon can most certainly cause poor cooling. If the system is stock then you can easily tell whether it is R-12 or R-134. R-12 will have screw on fittings and R-134 will have quick connect fittings, similar to an oversized air compressor fitting. If you have R-134, go to Wal-Mart, pickup a refill can but avoid the cans with oil, sealer, dyes or anything else they put in. I converted my Lumina over to R134 last year and it works fantastic but I went all out and bought all the tools needed to do it right. If you have any questions, let me know. Quote Link to comment Share on other sites More sharing options...
z34_nut Posted April 5, 2005 Report Share Posted April 5, 2005 i'm pretty sure that if you convert from r-12 to r-134a you need to replace the accumulator, and the compressor (assuming that its not in the best working order) which is common for an old car like yours. but, as kevin said, it should be 134a. otherwise, i would bring it to a dealer, i guess have them inject the dye.. (fairly cheap) then see if you got any leaks...(usually you get the car back with-in a half hour, but you need to bring it back the next day to run the blacklight over the system) your best bet is to drain all the current freon and replace it with new, along with compressor oil (should be changed every-ac recharge) of course..this is all ASE spec, i never said there isn't anyway to get around any of these steps Quote Link to comment Share on other sites More sharing options...
Justin Posted April 5, 2005 Report Share Posted April 5, 2005 If your car has always had good AC I would probably just take it somewhere to have them recover the old refrigerant and then fill it again with the correct amount. That way you know you've got the exact amount, not whatever's in there plus a can. If this is the first time you've noticed a lack in AC performance it could be a tiny leak, more than likely nothing to worry about. Quote Link to comment Share on other sites More sharing options...
cutlassdude96 Posted April 6, 2005 Report Share Posted April 6, 2005 my secondary fan onlys comes on when it 80+ and the ac on high Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted April 6, 2005 Author Report Share Posted April 6, 2005 It's R-134a. I guess it must have a leak. Awhile back it quit working well, so I put a can in it and it was fine. Then it got to where the fan doesn't run at low speeds and the air starts blowing warm. This time I had assumed it was the fan, but when I jumpered across the relay, it would spin. So I thought it was the relay, but I grounded its coil and the fan came on. I then thought it was the PCM, but I hooked it up to my laptop and could see the PCM never requests the fan to come on. I'll try another can of R-134a. One of these days I need to buy a manifold gauge set and learn how to use it. Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted April 6, 2005 Report Share Posted April 6, 2005 It's R-134a. I guess it must have a leak. Awhile back it quit working well, so I put a can in it and it was fine. Then it got to where the fan doesn't run at low speeds and the air starts blowing warm. This time I had assumed it was the fan, but when I jumpered across the relay, it would spin. So I thought it was the relay, but I grounded its coil and the fan came on. I then thought it was the PCM, but I hooked it up to my laptop and could see the PCM never requests the fan to come on. I'll try another can of R-134a. One of these days I need to buy a manifold gauge set and learn how to use it. If you get your hands on a manifold gauge set, your shooting for a low side pressure of 32 psi and a high side around 170-220. At idle though, the low side will be higher and the high side will be lower. You just need to make sure you have enough refrigerant in the system to move the oil around or you'll sieze the compressor. Quote Link to comment Share on other sites More sharing options...
White93z34 Posted April 6, 2005 Report Share Posted April 6, 2005 put the top down. thats one hell of a a/c system Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted April 6, 2005 Author Report Share Posted April 6, 2005 put the top down. thats one hell of a a/c system The top has a broken linkage that's no longer available from GM. No remaining stock anywhere either according to partsvoice. That's a project for another day though. Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted April 9, 2005 Author Report Share Posted April 9, 2005 I put another can of refrigerant in it and it didn't help the least little bit. In fact, the AC feels pretty warm. It didn't even change the pressure that the PCM is reporting. At idle, the pressure goes up to 180-200psi and then the left fan kicks on and causes the pressure to drop to 105-115psi. When the fan shuts off, the cycle starts over. The compressor runs the whole time. The air never really gets cold. Any ideas? Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted April 9, 2005 Report Share Posted April 9, 2005 It may be time to invest in an inexpensive set of manifold gauges. High side readings are almost useless without low side as well. When the second fan kicks on, how quickly does the pressure drop? Also, our V5 compressors never kick off, they are a variable displacement compressor. Quote Link to comment Share on other sites More sharing options...
Jim98GP Posted April 17, 2005 Report Share Posted April 17, 2005 Can someone tell me where the A/C lines are on a 89 Cutlass with the 3.1? I was going to recharge my system real quick but when I popped the hood, i couldn't find the lines! My 98 Grand Prix was a piece of cake. Of course, this is the 3rd 3.1 GM I've owned and know very well that they're a pain in a$$ to work on! Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted April 17, 2005 Report Share Posted April 17, 2005 Can someone tell me where the A/C lines are on a 89 Cutlass with the 3.1? I was going to recharge my system real quick but when I popped the hood, i couldn't find the lines! My 98 Grand Prix was a piece of cake. Of course, this is the 3rd 3.1 GM I've owned and know very well that they're a pain in a$$ to work on! Both high and low side valves are under the air cleaner. Unless you are an AC tech or have an AC license, there is no real quick way to recharge an R-12 system, unless you have already changed it over to R-134. Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted April 17, 2005 Author Report Share Posted April 17, 2005 Yeah, the AC valves on the first gen W's is in the worst place of any car I've ever seen. Quote Link to comment Share on other sites More sharing options...
z34_nut Posted April 17, 2005 Report Share Posted April 17, 2005 another cure is either a bad disectant bag (not filtering your AC right) or a clogged metering valve could cause these problems. getting your hands on a manifold gauge set would be great, its not that hard to use, really, it took only a day fo class to figure those out. I would say get a shop to check your pressure, at idle, at 2000 rpm for 20 minutes, and w/o AC engaged. once i get pressure, i can almost tell you exactly what it could be. Quote Link to comment Share on other sites More sharing options...
Jim98GP Posted April 18, 2005 Report Share Posted April 18, 2005 Thanks guys. I don't think my compressor is working anyway... doh! Quote Link to comment Share on other sites More sharing options...
GP1138 Posted April 18, 2005 Report Share Posted April 18, 2005 Thanks guys. I don't think my compressor is working anyway... doh! The compressor clutch won't engage if there's no refrigerant in the system. I thought my old Grand Prix's compressor was fucked until I converted it to R-134a and the thing cycled on once the refrigerant was added. Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted April 18, 2005 Author Report Share Posted April 18, 2005 Thanks, I'll have to pick up a manifold gauge set when they're on sale at Harbor Freight. I'm a cheap bastard so I can wait till a sale. Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted April 18, 2005 Report Share Posted April 18, 2005 Thanks, I'll have to pick up a manifold gauge set when they're on sale at Harbor Freight. I'm a cheap bastard so I can wait till a sale. Watchout when you buy the kit as it may be an R134 set. If it is, you can go to http://www.ackits.com and pickup converters. That is what I did when I converted my gauge set. Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted April 18, 2005 Author Report Share Posted April 18, 2005 The 94 has a native (non-converted) R-134a system, so I shouldn't have to worry about that, should I? Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted April 18, 2005 Report Share Posted April 18, 2005 The 94 has a native (non-converted) R-134a system, so I shouldn't have to worry about that, should I? If it is an R-134 system already then you have nothing to worry about (unless Harbor Freight is selling the R12 gauges on sale). Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted April 18, 2005 Report Share Posted April 18, 2005 Thanks, I'll have to pick up a manifold gauge set when they're on sale at Harbor Freight. I'm a cheap bastard so I can wait till a sale. I don't know that they'll get much cheaper than this. http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=2435 Quote Link to comment Share on other sites More sharing options...
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