When i first start up the car and i put in the clutch it jumps about 1k(on cold start). i take it off and it falls back down. Also, when I pump the brake a few times the idle jumps up a bit(when engine is cold) Other things that might be relavent is sometimes my car will idle at 750 sometimes 850, other times 950, even 700 or 650. It doesn't ever flucuate or surge. I was jsut wondering if anyone could help me get a better idle. Also i get 20mpg. I was thinking to change the o2 sensor. Anyone else got any ideas? Thanks- Corey

 

i have a b16a1 wit j1 tranny and HD ACT clutch .
it does that. no problem its normal. its always got some kinda load on it. as if u lift the car up and release the clutch the wheels will spin in neutral. but can be stopped by hand. brakes also are engine related. as they are usually vacuum powered. which would effect the idle.
dunno if its SUPPOSED TO but it does on mine. no problems though. my cars a 91 crx si. should be fine like that. if your worried about gas mileage these wouldn't matter. the o2 sensor would greatly.

 

i'm going to have to say this is normal operation of the brake booster.

 

Any ideas why it idles at different rpms all the time?