I'm not sure if this is normal, because I've never noticed it before. When I start my car up the idle steadily goes up to 1500 or 2000 and then steadily drops back down to "normal" idle which at cold is alittle more than 1000rpm I think. I've just started noticing this after installing K&N air filters and changing the oil. Any ideas? Drivability hasn't been affected and it runs fine and all other gauges are normal but if there is a problem I wanna identify it before anything comes of it...

BTW, the engine is a 305 TPI w/ 32k miles.

 

im having the same issue anyone have any ideas

 

I'm pretty sure that this is normal. I'm yet to see a third gen that doesn't do that.

 

Could try cleaning the IAC.

 

I replaced my IAC, TPS, and recently rebuilt the whole top half of my motor and it still idles as high at 1500rpm's at start up. As long as it goes back down to normal, it's nothing to worry about.

 

My '97 LT1 does that too... jumps to about 1500, then slowly drops back down to about 1000 over about 5 seconds or so. I'd say its normal. Fuel injected cars pump in quite a bit of fuel on a cold startup, so they usually also have the IAC pretty far open too so its got lots of air and fuel for an easy startup, similar to what a choke does on a carbureted engine. Once the engine is started, the higher-than-normal rpms burn off the excess fuel faster and build up oil pressure quickly. Then it will drop it down to its normal cold idle presets.

 

Its normal on 3rd gens. It helps with warm the engine up quicker during a cold start and build oil pressure.

 

yea i would agree that this is normal. both third gens i have owned have done the same thing even when they were bone stock.