I know this sounds really stupid, but how do you check for split BLM's at idle?

I have the www.obd-2.com scan tool...sorry for the dumb question!

 

I'm not familiar with your software but, they're are two types of BLM short term and long term. The short term counts will adjust very fast to get the long term counts in the right perimeter. Split Blms would show for instance 110/131 on the long term counts. If the counts are not the same on both sides then you have split blms. But, if they are not drastic like less than 5-10 apart I would not worry about it. If you have a cam than it is normal to have split blms until you crack the throttle.

 

Well I guess what I should ask is, what exactly are the BLMs? the O2 readings?

 

Injuneer has a good write-up on BLM's; it's written around the Scanmaster but it applies:

http://members.aol.com/InjuneerZZ/Sc....htm#step%2020

 

Matt your car doesnt have BLM. That is an old school OBD1 term.

You should have long term fuel trim and short term fuel trim. Sometimes called LTFT and STFT.

If your bank 1 and bank 2 LTFT % are different, then your "BLM"s are split. How much is ok on a OBD2 car? Not enough experience to tell you. I dont think I would worry about ~5-7% on a cammed setup at idle. Those numbers should pull pretty close to each other cruising.

 

Gotcha Jared...must be why I never saw BLMs on my scan tool.