when i start my car up it turns over and then it will idle for a while at about 1500-2000 rpm for an odd amount of time. sometime after i drive it for a while it will go down to about 750.. any ideas on why it is doing this and why it is doing it for so long? could it be carb issues?

 

Specs on the car please... Motor, trans, carb type. I would check for vacuum leaks.

 

its an 86 iroc with the 305. im assuming it is the 650 carb. i took off the stock breather and there is an open vacuum line. advance didnt have a big enough plug to put in when i went down there.

 

i also just went out there and noticed there is oil sitting right below the carb. any ideas on what that is from?

 

How many miles are on it?

Where is the oil located,on top of the intake or inside it?

Might just need the carb gone through and cleaned out.

 

40 on the motor.. a buddy said it was either blown valve cover gaskets... cracked intake or a piston ring. i am going to change the valve cover gaskets this weekend and see if that solves the problem hopefully

 

Could be any,maybe the V/C's are a little loose.

An open vacuum line will cause a high idle,get that fixed.

 

If it has an automatic choke that will do it. It idles fast when cold and slows it down as it warms up.