I'm pretty certain I have no vacuum leaks, idle is very smooth.

I just added highly ported heads and intake, a 08-302-8 (264) cam and Hooker 2055s to a stock 5.7 in an '89. The injectors are still the bosh IIIs, almost new.

My BLM is always up in the high 150 range at idle, down the road its less, but does this indicate a need for fuel - i.e. larger flow injectors? Or maybe something more insidious?

 

If the MAF is de-screened and/or the intake track prior to the MAF has been changed, I can see this happening. Need to work on the MAF tables to correct it.

Even a small air leak past the MAF will cause high BLMs at idle. Even the incorrect PCV valve will do it.

RBob.

 

Is the high BLM count a symptom or a consequence? I think youre saying it is a consequence but I dont want to put words in your mouth.

If the MAF tables are tweaked (the MAF is stock with both screens) then I can bring down the BLM count? Should I raise the values in the MAF table?

 

It would be a consequence of an air leak past the MAF. Un-metered air, and the MAF won't account for it. Was the high BLMs present before the heads/cam swap? If so then I wonder if the injectors are a tad on the smaller side flow rate wise, or the injector compensation values are off.

There is links to good info in the Tuning Guide Book Sticky on how the MAF tables/scalars work.

RBob.

 

Actually BLMs were just a tad rich before the work and additional parts were added.

I'm going to do a carb-cleaner test again just to make sure there are no post-MAF leaks and i'll report back.

 

Used a whole can of carb cleaner, from the intake base thru the runners and all the way back to the MAF outlet, didnt get a rise in engine RPM at all. Am using a Tech 1 because I cant get TunerPro to connect and datalog this car.

Anyway, the O2 seems to stay very low = like under 100 even after idling a few minutes. But closed loop BLM stays around 134-138, and the INT stays in the low 130s. I sure wish it made sense, but to a novice like myself, it doesnt. Any suggestions?

 

Corvettes are cool, but the ARAP bin wasnt nice to me. So I got the AUJM bin from the gearhead site, loaded it stock into the ostrich, and joy! good running, BLMs playing nice - just a little tweaking of the AFPR got them within 4 of 128.

Now i'm messing with things from what probably should have been my starting point in the first place - the stock bin. I think the AUJM was the stock bin? Anyway, big improvement just by raising the spark tables by 5%. Fun! From my 0-60 times and using the online calculators, I'm right at about 375fwhp right now. I'm hoping with some more experience and experimentation to get another 25. Hopefully ...

 

Just to finish this up, #8 and #6 plugs were not tight (new hookers), I didnt realize you cant get a normal plug socket on them, and thought they were tight.

Just cut a cheap old spark plug socket down to about 1/4" of the wrench-flat part, and was able to get that over the plugs and get a box end wrench on them from below. Made all the difference.