Vortec swap, all stock, only mod is a spacer under TB. Have been chasing BLM's for abt 30 learns. My timing seems odd, replaced ICM, new hardened gear, pickup coil, cap, rotors, wires plugs, etc. At idle my rpm's go from a low of 575, to a hgh 675, closed loop,SA=low 15 to hgh=19, spw= 1.8to 1.9. DC%=3 to 4,! INT=125 BLM=128. On a 50mph steady cruise, RPM's= low 1200, hgh= 1375, map =65 steady, SAgoes from low=21 to hgh=23 closed loop,sPW=3.5 to 3.7, DC%=14-16. Initial SA=0.00, idle state SA=20.04, at dist. set at 0. I can't get my BLM"s to come into line or even close for a good tune. Can someone point me in a direction? Are these SA numbers normal. Not a DA when it comes to good ole American Chevy V8. Need HELP! A bad squeal at my idler pulley, I can't get quite has had my attention, still squealing, while trying to get my tune in order. Thanks for any help. EGR, not in use blocked off.

 

With the EGR blocked off, is it disabled in the calibration?

Whenever I've chased BLMs all over the place, there was something mechanical wrong. Such as an inadequate fuel delivery or a vacuum leak.

Need to fix the squealing tensioner. It can drive you nuts, but can also cause mild knock counts, or even slow accessories.

POSTED:

At idle:

rpm's go from a low of 575, to a hgh 675,

closed loop:

SA=low 15 to hgh=19
spw= 1.8 to 1.9
DC%=3 to 4
INT=125 BLM=128.

On a 50mph steady cruise:

RPM's= low 1200, hgh= 1375
map =65 steady
SA goes from low=21 to hgh=23

Closed loop:

sPW=3.5 to 3.7
DC%=14-16
Initial SA=0.00
idle state SA=20.04 at dist. set at 0

The idle RPM fluctuates a bit. But the INT/BLM is well within where it should be.

RBob.

 

Thanks RBob, nuts, was already there without the help from the idler pulley, on my 3rd one now, abt. to try another. Will chk. on the vacum leaks, really hadn't had time since I put it together, been focused on pulley and 134 air change over. I have my brake vacum routed to the spacer I mentioned above, drilled and tapped as I put it together, would this affect it? Was thinking to change it to the port on the intake, which is the GMPP. Thanks for the help.