could be the electronic brakes? Since you have an SSE, you have electronic brakes. Mine is fairly weak, and after holding the brakes for a bit [like at a light] it'll start pressurizing again, but I really can't hear that if the engine is running. I just know it'* running via the voltmeter.

OK, I'll bite......What exactly are Electronic Brakes????

It'* most likely your AC compressor cycling ON and OFF. Mine did that when it was low also. You probably still have just enough for the pressure switch to see freon and it keeps turning it on and off. You should be able to unplug the connector on the compressor without causing any problems. Just remember it is unplugged if you charge it again.

Better yet and easier, if you look in the back of the accumulator ( big silver canister on on the firewall on the passenger side of the car) you have your ac lines running into it. On the back of it is connector going to another pressure switch. If you unplug that one, it will stop your compressor from cycling. I know cause I forgot to plug it back in when I did some AC work and took me a minute to figure out why the compressor was not cycling.

The Teeves system I think uses an electronic pump or such to pressurize instead of engine vacuum.

Yeah, I apologize about the lack of explaination. But in 88-90 all ABS-equipped cars [SSE'* came standard with it] had electronic brakes.

1991 SSE = non-TEVES. Vacuum, not electric.

damn i'm retarded, i thought he had a 90. But i did have the explaination right .

Cooling fans? Maybe they are turning on? If the ac compressor is on, so is the low speed fan. So if the engine sounds fanny, like the fan[*] are running, then maybe it'* the compressor.

I have had my compressor cycle WITHOUT the fan running, of course like I mentioned in an earlier post, it was low on freon so it was cycling quickly.

That may be why... i've never had mine cycle but whenever it turns on, that low speed fan comes on within 5 seconds.