Okay so my timing is advanced to 12 degrees and my engine has a funny way of showing from idling from 2000RPM's to 1500RPM's. and this is on an aftermarket tach. Now Ive had my engine idle at around 700-1000RPM and it just feels as if the engine is going to die on me and the power steering sucks at that RPM especially if im in slow traffic or in a parking lot. My question is, is it necessarily bad if my engine is idling at those RPM's (1500-2000 rpm)?

and anyone known what causes the engine to fluctuate between 1500RPM's to 2000 RPM's? Its like at every stop light it decides to idle differently.

 

vacuum leak or contaminants in your carb bowl and idle passages.

 

ive checked all the vacuums and ive pretty much plugged em up...and the carb i rebuilt it not too long ago (4-5 months ago)

 

1st idle . will idle high and 2nd idle will idle low.. my iroc does it similar at start up, it ranges from like 1200 to 1500, but never in the 2000 range,, but say if i hit operating tempeture and i shut the car off, then turned it back on, it will go to 2nd idle, which is 750 rpms, exacttly as what specs say in my manual. ( (1985 Iroc-Z H.O. 5.0L 4bbl)

 

hmmm...interesting never knew that.