BLM's Up-Why?

[good2win22]

Run some smoke thru it and see where the leak is if any at all

[Steve Wood]

sounds like it fixed itself....ever yone else wants 128 and you got it!

[Scoobum]

I've never bought into the 128 crap. Steve, you and I both know if the BLM's rise out of nowhere...then something's up. That's why we have scan tools...to monitor this stuff. It's raining as usual, so nothing will likely get checked today. If that big yellow thing in the sky comes out I'm gonna check for exhaust leaks...and slap in a new PCV valve and 02 sensor.

I want everyone's input on this. I've stated here before that my opinion of Felpro head gaskets is that the quality level has slipped. I think I read a post from Paul from MAGNA state the same thing. The fire rings are literally egg shaped. Is it possible the combustion could travel across the open deck and head to the fire ring and eat away at it...with the higher combustion pressure forcing the fire ring towards the intake side...causing an air leak and making the BLM's rise.

[Steve Wood]

Given the wide range of correction provided by the ecm, blms are not all that significant within the greater scheme of things and people tend to forget that blm are ignored at wide open throttle.  I find them most useful if there is a sudden change from the normal range indicated by the ecm meaning something has changed in the car.  A change of 10 can be attributed to both ambient conditions as well things like fuel pressure or leaks.  It's all a guess by the programmer initially anyway.

I agree with Paul, I think Felpros went down hill several years ago.  That's why I always suggest the VR's on the average car.

[Scoobum]

I race this car in temps in the 40's to 90's...and the BLM's stay locked at 118...so it's not that. I swapped out a bunch of vacuum lines. I'm down to an exhaust leak...or a headgasket on the way out on the intake side. I monitor this engine like a hawk. Max boost has been 25 PSI and always on a safe tune without a hint of KR. I'm gonna be pissed if this is a headgasket going south.

[Steve Wood]

After about 17 years of being beaten on hard, my son's T is pressurizing the radiator a bit when it is cranked up....I guess the hgs are beginning to seep

[Scoobum]

Update. I checked the nuts on both sides where the crossover bolts up...and they're snug. Proper igniton module is installed. BLM's still at 128. Now riddle me this. I removed 2 vacuum hoses from the steel lines. First the one going to the EGR...which I have capped...as I did away with it. BLM's stayed at 128. I removed the one going to the one way check valve...BLM's at 128. Should the BLM's not have gone up with the huge vacuum leak?

[Steve Wood]

Is this the idle blm block that is off?

[Scoobum]

Is this the idle blm block that is off?

Yes

[Steve Wood]

what about the higher cells?  Are they also higher than before?

[Scoobum]

what about the higher cells?  Are they also higher than before?

Steve, I have lots of PL files from recent track outings. I'll have a look and post back tonite. Thanks for your help on this one. It's got me stymied.

[Scoobum]

Steve, I have a spare ECM we can try if you think that could be an issue. I've seen them do some stupid things. I'm ordering a new 02 sensor tomorrow morning. It'll be here Tuesday.

[Steve Wood]

I would start with a new O2 sensor just for the heck of it..mainly because the O2 sensor is the reading that the ecm uses to decide what the blms should do

[earlbrown]

Should the BLM's not have gone up with the huge vacuum leak?

The INTs should move quickly.  If they spend a lot of time elevated, the BLMs should follow.

[Scoobum]

Just finished straightening up the garage...and found 2 new Denso 02 sensors still in the packaging. Think Glen had a half price sale on these awhile back and Dan Keller and I bought a bunch. Steve, it's pouring rain again. I'll get a PL file in the morning so I can make a comparison of the cells. I'll swap the new 02 sensor in then as well. Thanks for the help guys.