Chevy & GMC Vans

Looking for a diagram that shows the Idle Air control on an 87 Astro or whatever controls the engine rpm's when the A/C is turned on.
The engine RPM's are supposed to go up a bit to compensate for the A/C compressor's load. My van goes way too low on the RPMs when the A/C is on and there's a lot of vibration when this happens.

bump

I have the same problem with my 87, and the a/c went out days after :(

two vehicles and same issue with me this summer. i think it has something to do with the compressor not being lubricated enough or something going inside of it. the idle gets low... it's like there's a huge drain on the motor .. or the entire pulley system for that matter.

perhaps someone else knows for sure.

crash wrote:two vehicles and same issue with me this summer. i think it has something to do with the compressor not being lubricated enough or something going inside of it. the idle gets low... it's like there's a huge drain on the motor .. or the entire pulley system for that matter.

perhaps someone else knows for sure.

Exactly- are these compressors known for not lasting long?

Seems to lag my motor down to 5-700 rpm

well the first problem I had with my van, was I turn the AC on and then I got vibration, well it was due to power robbing and the alt could not provide the juice that the Rig needed so I rebuilt the alt and all was great after that, simple fix really and simple test

1. start van
2. disconnect battery
3. test power with volt meter
4. turn ac on
5. test power again


if there is too much drop or stall you need to have the alt tested

worked for me.

Oke

wow 9 posts and you are already helping members

is that a bad thing, I cant pick up computer lingo lol