Idle issue with Climate Controls on

[aletheuo]

Got a job1 01 ST and I know I've got a vacuum leak somewhere because under heavy load the heat goes to defrost and when climate controls are on I have intermittant idle issues. I just need a little help finding the leak.

I have no idle issues when climate control is off. With climate controls on it has issues but with AC on it has even greater issues. Still drivable, everything still works, but it's way more annoying.

Thoughts on where to search? I've sprayed down every coupler in the engine compartment but maybe I didn't spray the HCV when the heater was on... maybe I should try that next?

 

[aletheuo]

I think there's multiple issues going on because it was running great while climate controls were off until yesterday morning. Started doing same stuff (but less of) when the cc are on. Just cleaned the IAC which was pretty dirty. We'll see what happens.

 

[aletheuo]

Replaced a one-way check valve in the vac system, replaced the pcv and intake vac lines, fuel filter, plugs and wires and now runs like a champ. No point leaving any stones unturned.