when in gear RPM's stay a little bit above normal, around 650 RPM while idiling

if i take it out of gear, as in put it in park or neutral, RPM will shoot up to 1000 - 1100 and stay there until I put it back in gear. this is also while idling. no gas is applied.

is this idle control issue of sort?

it was worse before i cleaned throttle body and EGR valve. after cleaning those things this issue went from wild to mild but it is still there.

what should i check/clean to help solve this? i drive to work every day in heavy, heavy traffick with more stop than go and this issue is effecting my fule consumption.

 

have you ever cleaned your idle air control? its on the driver side of the throttle body, closest to the cab not the bumper. two torx screws you pull it out and give it a good cleaning. make sure not to move the plunger while your cleaning it. also clean out the passage were the plunger goes in.

 

why should i not move the plunger?

 

it controls how much air is getting past. im pretty sure its supposed to be an inch and an eighth from the mounting plate to the top of the plunger. might not be a bad idea to make sure its in spec while you have it out. maybe search that to make sure im right on inch and eighth.

 

Cant a vacuum leak cause and idle issue like this?

 

Ihave the same prob on my 99 blazer . Bought a new IAC on ebay & the nose is flat the old one the nose is rounded . Will this make a differance? jim

 

It should have a rounded (more cone shaped) nose on it. I haven't seen one that doesn't...

 

sounds like a idle air control problem or a vacuum leak to me. have you got any vacuum reading from the engine idiling?

 

no idea what you mean, what that is or how to do it.

there are no codes

 

whats the vacuum of the engine at *idle*. you hook a vacuum gauge to the intake or a vacuum line and the gause will give a vacuum reading. anthing over 18 is good