I have a vaccum leak somewhere in my engine, the iac counts are at 0 if not a little over in idle and the car is running very lean. I think the blm is at 157. The check engine light came on today pulling out of my neighborhood for a lean condition picked up by the o2 sensor. What are the first places to look in an effort to save myself a little time?

 

what type of induction do you have? it could be a leak on the manifold gasket. I am just putting 2 +2 together here, but: if you had a vacuum leak at the manifold gasket, i would think the vacuum would draw in excess amount of air. air that adds to what is already being pulled through the throttle body/carb. Obviously, the way that the engine is designed, the carb or TB is the lone metering source for incoming air, so i would think that if air were being pulled in elsewhere, i.e. intake gasket, it would create a lean mixture.

I think as long as the BLM doesnt hit 160 or so (i think thats the number), the computer can get the mixtre just right. but youre awfully close. I think 125-130ish is the ideal, and your a ways away from that.

 

its an 86 lb9. I just need some ideas of common vaccum leaks so i dont spend all day tomarrow looking for lone elusive leak.

 

first thing i'd check would be the hard plastic vac lines and then i'd look towards any rubber lines, then i'd start sprayin down common area's such as around the intake, around the base of the carb or tb, etc..

 

one common leak is the hose that goes from back of carb thru firewall for your climate controls. those hard plastic lines are infamous

 

its an lb9