high BLMs-----------gurus inquire within

[spooky]

Im chasing high BLMs and was wondering if a pre-MAF sensor would contribute. I have reset or adjusted everything ecept for changing the idle air control valve. New MAF sensor seemed to help at first but no lucky. New motor and o2 sensor, reseated the crossover pipe to no avail. Adjusting the FP is just masking and I dont want cylinder wash from the extra fuel, which I tried anyway.
thanks in advance
J.

 

[SFITurbo]

Look for an exhaust related leak or vacuum leak, ie.. crossover or EGR gasket/vac. block or lines.

 

[streetknight]

vacuum leaks. I chased the same issue for weaks. Razor did a great thread on this on another board though I think. Start by putting a piece of gasket material under the vacuum block on top of the throttle body. Just push the bolts thru and use some vaseline. don't cut holes like the regular gasket. This will block off vacuum to all the lines. Reset your ECM and if your BLM's go down, it's a vacuum hose. If not it's like an intake gasket, TB gasket, etc.

That's what to check first.

Although mine did turn out to be bad fuel injectors on my car.

Hope this helps and do a search on "High BLM's guru" there was a lengthy thread on this few weeks ago. Hope this helps.

 

[2QUIK6]

Did this just start to happen? If so what had changed?
If it has been this way ever since you got the car, maybe the chip is the wrong one for the injectors?
Are the BLMS high in every cell (rpm/load) or is it just idle or cruise?

High BLMs means the ECM is adding fuel for a lean condition. Also, swap the MAF with a known good one if you have access to one, MAF calibrated incorrectly can cause it as well.

 

[spooky]

I guess it just started to happen, right after eng rebuild. MAF is new (refurb) and only at idle they peg out. I think the chip I have well pretty sure its too much timing, Its an older pit bull chip anyways Ill look at what I checked already and what was suggested........

 

[2QUIK6]

If just pegging only at idle, its most likely a vac leak somewhere. MAF calibration would be the secondary suspect since its a re-man unit.

 

[TurboJim]

Get it on an emissions analyzer and see if its in fact lean. Co and O2 will show this. If its rich and BLM's are high, I'd shoot at the O2 sensor. May be lazy enuf to skew things and not cide. See it all the time.