Two Part question.
1. What's a good idle speed for the car when it's warming up?
2. I replaced my brake booster cause I was told it had a leak (which is why I figured I get a 200 RMP's drop when I put on the brakes with it in gear) Welp, new brake booster but still old problem. Any idea why the RPM's take a 200 RPM drop when I put the brakes on with the car in gear? Thanks.

 

a good idle speed imo is somewhere between 6-7 hundred

dunno about the drop when you hit the brakes

 

What year is it?Generally 750-850 for auto and slightly lower for a stick

 

Personally, I like to rev the engine up to 9000 rpm to warm it up... (do you guys remember that typo post? - that was funny)...

 

I meant what should I set my engine (fast idle screw) RPMS at while the choke is on and before the car is warmed up and kicked down?

 

800 rpm is the accepted norm for the manuals. The C4's need a tad more because they are woosies.

 

"800 rpm is the accepted norm for the manuals. The C4's need a tad more because they are woosies."

I'm heading down to my garage right now and getting on my knees and whispering tomy C4 that it is a wussy. It'll probably start itself and do a big old smoky burnout all on its own...

(BTW FYI - I just gotthe C4rebuilt by a fellow named Neal Rhodes in Elizabeth, CO... He's THE MAN when it comes to a transmission and also FE motors.)

 

800 rpm? That's a bit low. 1200 rpm is generally where I set my stockers...if I bother with a choke anyway.

 

Great, question 1 done. Anyone want to take a stab at answering question number two?

 

Which number did you go with? This thread alone has several answers between 600 - 1200 RPM (not including the 9000 typo, yes I remember it [shaking head]).

As for question number two, I still think there must be a vacuum leak somewhere. It doesn't have to be in the brake vacuum line, but activating the brakes could be pulling enough vacuum to open up a leak elsewhere. It might be time to replace all of your vacuum lines. Another thing you should probably check is to make sure all of your vacuum plugs are nice and tight.