Originally Posted by
S-351R
Well, I matched Desired Idle with the min this TB was giving (~1050rpm) which allowed to spark to work around 10-15* doing typical idle trims. Fuel Trims and WB were consistent, and still glowing headers at idle.
Unplugged MAF and verified fueling on WB and it was very lean on the LWMF table (not dialed in yet, but had reasonable values from another SC car), fine but does explain that it was leanness that was dropping RPM idle despite the big TB.
Swapped in stock MAF sensor in same large 4.5 tube, scaled it, and trims were back to fine, MAF lb/hr dropped a little by about .2 (2.1 vs 2.3 at 1050rpm idle)
Idle timing good, still started glowing pretty quick.
2500rpm hold with solid 14.5's AFRs, 30s timing, and still glowing (even more) on both sides... With the timing high, and stable higher RPM fueling, what would cause this to get worse?
Timing was verified with light and even if ring had somehow shifted it was commanding plenty of spark.
Is cam timing the only thing reasonably left to verify? (Rather large cams, locked out...)