Sarcazmo

Hey guys, I know this has been covered before so I apologize in advance. Just making sure I have the procedure done right.

I just purchased a new to me 87 sr5. I noticed when I turn the A/C on the idle wasn't going up. I did a little research and it has a separate idle adjust knob (with the white screw top) that should only adjust the idle when the A/C is on.

So I adjusted that until my idle with the A/C was ~900-950. Everything is great until I turn the A/C off. It kicks my regular idle to around ~1400rpm. So the AC idle adjust knob is adjusting my regular idle as well.

Did some more research on here and found the vacuum diagram. Checked my hoses from the VSV to the actuator and they are correct.

My volt meter met an untimely demise earlier this week. As soon as I get off work I'm gonna head to my buddy's to use his. Question is, is there anything else I can check until I get my hands on a volt meter to check the vsv?

I've run into a couple other threads and even a couple of vids on youtube and it looks like the VSV could be a likely culprit.

Thanks!

grumpin

Hi, could be a vacuum leak. Might try swapping the hoses to the VSV to see what happens. I know you said you checked them, but incorrect hose routing will cause that. If that controls your idle there is a leak or routing issue somewhere. I would think the VSV would be on or off, or not work at all.

Sarcazmo

Thanks for the reply!

Just went outside to mess with it.

Pulled it into the shade. Truck was idling ok. Flipped on the AC, idled up and stayed there. Sweet! I thought maybe somehow it had fixed itself. So I revved the engine. Once I revved the engine the issue came back. Turn off the AC and the idle raises to ~1200.

So I swapped hoses @ the VSV. Same issue I'm afraid. Idles around ~950 with the ac on and goes up to ~1200 when switched off. The AC idle screw still seems to be controlling the regular idle as well.

Hopefully I'll be able to grab my friends volt meter in a couple hours and pull the VSV to test it.

grumpin

Well, darn! Yes, check that VSV out. Hope you find something soon.

scope103

Sounds like the VSV is not working as it should. When you turn on the A/C, nothing is happening at the idle CONTROL, but the load of the compressor slows it down to 950.

You could try just bypassing the A/C idle up, get the idle set correctly, then plumb it back in. With the A/C off nothing should change, and then with the A/C on the idle SHOULD increase. You can also test for appropriate vacuum with your thumb on the end of the disconnected vacuum line.