I am having a problem with my Terminator EFI system. I haven't been getting much help from the Holley Fourms - a couple of suggestions but no solution to my problem yet.
Overall, the car runs well. It pulls hard an idles well when the idle spark is turned on. There is an occasional low RPM bog (at or off idle) that makes the car want to stumble. When cruising or accelerating, it runs great.
Right now it idles pretty well. Right around 900 RPM. However, if I try to rev the motor without a load, the RPMs will hunt/bounce up and down and never settle on a steady number. AFR goes full rich to full lean (10-28) during this hunting. At idle, AFR varies from 12-14 with a goal of 13.5. If I turn off Idle Spark control or turn on Static Timing, it will hunt at idle too.
I'm not sure where the problem is. Holley forums (Danny mostly) thinks I am either too lean, have a failing WBO2 sensor, or an exhaust leak. I'm not sure any of these are my problem.
Lean?: the Learn table is removing fuel, anywhere from 2-5% in these areas. Learn is active during these bouncing fluctuations.
WBO2 failing?: This has been happening for a while. I replaced the WBO2 sensor a few months ago. This was happening before the replacement and continues to happen despite the new sensor. I don't want to replace another $100 sensor and have it also not be the solution.
Exhaust Leak?: I resealed everything from the heads back. Still bounces.
There is one suggestion that I may be having a misfire causing a false lean spike, then overcompensation by the ECU causing a rich condition which causes another misfire. Not sure how to test that. I'm getting spark in all 8 as verified by a timing light.
If anyone is willing to look, here is my Global Folder (datalogs included inside ZIP:
Click Here
Here is a picture of the log while hunting (if it will load,
Click Here if it doesn't):
If it matters, I have the following:
408 stroker
Cam 230/236 at .050
MSD 8452 with Ford brand Ignition module
MSD wires, Champion plugs recommended by AFR
AFR 195 heads
Mallory HiFire 6853M ignition box (MSD 6AL copy)
Mallory 30440 ignition coil
Any thoughts on what's happening?
Thanks in advance, Tom
Holley EFI Tuning Problems
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