ryaskovic

I'm still trying to figure out why my right bank is adding fuel (140+ BLMs) anytime the TPS is closed. Car is a new 383 with 224/230 XE cam, ported LT1 heads, Ford 30# SVOs, Hooker LTs. It ran fine for the first 100 or so miles and then I started getting the funky BLMs on the passenger side. I can't find any leaks, vacuum or exhaust, on that side anywhere. O2s are new.

If I reset the PCM and start the car, both O2s start climbing until about 60 seconds into the run time. That's when the right O2 starts to fall until it bottoms out. Left side is fine. Once I hit closed loop, the right side BLMs ramp up to account for it.

I was fiddling around yesterday, just experimenting, and decided to see what would happen if I tried resetting the PCM, disconnecting the MAF, and starting it up (SD mode). I got some interesting info that I'm hoping someone might be able to explain: the car started normally although it stumbled a bit at
first. The right side O2 started falling where it normally does and I hit closed loop soon thereafter (car was already warmed up so I hit CL pretty quick). Anyway, when it hit CL, both sides were pulling fuel equally (113-115 BLMs), which doesn't jive with the MAF-enabled performance. Then what really surprised me, the IAC counts ramped up in a matter of 5-7 seconds until they
maxed out! By that time, the engine was surging violently so I shut it down.

Can anyone explain what caused this?

TIA,
Rob
95Z28