This pertains to a GSL-SE, I have been fighting my BAC valve trying to figure out why when my AC comes on, the idle immediately dumps off then sometimes rises back up and other times it dies entirely. The first thing I noticed is the ACV wasn't clicking anymore so Midwest 7's was gracious enough to find a working one for me to swing a deal with and replaced my old one. I went through the usual FAQ idle testing guidelines and my throttle plates did need a little fine tuning due to the age of the car but it still kept dieing right when the AC came on. I also tried adjusting the ACV screw and it like made no difference at all. I even hard wired the ACV valve open and it should have jumped like 200 RPMs and the idle never went up or down as I did anything with the adjustment screw. So I finally just gave up since it ran and idled great at 800 rpm with no AC compressor.

Well the other day I go and FINALLY replace my power steering pump, hook everything back up and suddenly my idle is not only a little higher than normal but as soon as I hit the AC the throttle jumps. It also stopped dieing with the AC on. I tried hard wiring the ACV valve and it definitely is increasing the RPM's like the FAQ said it should have.

My question is this... is the plug on the power steering pump in ANY way connected to the BAC valve or any of the other solenoids because I am totally confused here on why this whole system starting working.

 

According to the FSM the air supply valve supplies bypass air during a/c and power steering operation. The power steering oil pressure switch appears to be directly tied in with the a/c ckt, best as I can make out from a quick glance at the schematics. It looks as if your problem may have included an issue with your power steering oil pressure switch. If you find your idle is too high with the a/c, try adjusting the throttle opener.

Hopefully Longduck will review the thread in go into detail.

 

Strange new problem... the other day, while running the RPM's up... after letting it come back down I noticed the steering got tougher. By the time I got it home... steering was no longer power assisted. The pump was a new remanufacturered one I just put in, only about 100 miles on it total. After the car sat for a day and cooled off, upon starting the car and driving it the next day, power steering was back until the car got nice and warm then stopped working again. Any ideas?

 

Check the fluid level. To fill a fresh pump, you need to turn the steering wheel lock to lock several times to work all of the air out of the system.

 

I have the same problem but now the idle is totally wacked out. It will not hold the idle at all and stalls. I tried adjusting the various screws and everything. Now I am cleaning and lubing the throttle chamber, will take off the BAC and check it out. It could be that my power steering switch is messed up. Where is it located exactly??

 

I'm thinking that too, I saw some bubbles in the fluid last time. I also thoroughly bled the system but it isn't helping. I think the switch may be out... I believe the switch is located directly on the line itself. What's funny is the pump I got as a replacement had no switch, I had to take it off my old pump... thought that was odd.

 

I had a little time today to clean and lube the BAC vent system. I'll have to deal with the other crap this weekend. I'm tired of not being able to drive the 7.

 

Not claiming to have the answer but just my thoughts. If there is an idle issue that seems connected with the power steering, the oil pressure switch (located behing the power steering pully) would be a place to focus. As the power steering fluid pressure increases it causes a load on the engine via more work to turn the steering pump pully. This increase in load is picked up by the oil pressure switch which increases the bypass air to bump up the idle. I could not find a testing procedure for the oil pressure switch in the fsm but have to believe it is nothing more than a variable resistor. In which case I would disconnect the connector and connect an ohm/multimeter to the pins of the switch. Increase the engine speed while moving the steering wheel and check for a change in resistance. If there is not change in resistance, the switch may be suspect. If there is a change, damned if I could find any reference numbers to indicate a suspect switch. I would be more than happy to apply the same test on my working unit and share the results if it helps.

A loss in steering performance would have me looking at the pump or oil control valve. If a rebuilt pump was installed, issue may be with the control valve which is electronically controlled complicating the issue to either electrical or mechinical. The fsm only provided me a limited understanding of the control valve and would suggest downloading this section of the manual to see if it applies to your issue.

 

Is that the pulley that is located below the A/C pully near the bottom of the engine bay? If so, I had to tighten it the other day when it was making strange noises. It's tight now but it sort of wobbles when it turns.

 

my fluids are filled and fine and my steering just goes out outa no where and my cars been making very weird noises lately so strange that i cant explain it it sucks

 

Well apparently this power steering issue is more common than I originally thought. I'm going to test the switch and see what I can discover.

 

So where is the power steering pulley and switch?

 

Nevermind, I found it in the service manual. That was the pulley that wobbled last week and I tightened. It stil doesn't look right though when it spins. Does that mean that the pump or something with the pump is bad?

 

Well, believe it or not, I think my biggest problem was that the accelerator cable wasn't being held by the clamp before the two adjustment screws in the engine bay. Then the cable was really loose and the idle sucked really bad. We'll see if this works or not.