Wideband O2 Tuning
06-08-2009, 02:30 PM
#31
Platinum Member
Platinum Member
Blue,
You were possibly right on the lean but it is confusing as the carb is now so far off that we have sent it back to Holley to be tested. We did find out that we made and error in setting up the new Crane ignition boxes. If you don't use the Crane ignition retard feature, you are to directed to cut off the brown wire and set the dial on 1. We cut the wire, but neglected to reset the retard that is pre-set at 8. With a 8 setting, the retard is X 2 = 16 degrees! Woops...
We fought the carb all day Saturday as it got extremely lean above 4000 RPM (testing with AFR meter). Tried new PV's but no change.
I am think that the BIG backfire we incurred in May (with 16 degree retard) may have damaged the carb as we could not get it under control. Will have to wait and see what the Holley Custom Shop says.
We did swap the carb's on Sunday and the problem followed the carb...way lean above 4000 RPM.
Couldn't spend anymore time trying to figure this out as I we want to participate in LEOPA's July Poker Run.
You were possibly right on the lean but it is confusing as the carb is now so far off that we have sent it back to Holley to be tested. We did find out that we made and error in setting up the new Crane ignition boxes. If you don't use the Crane ignition retard feature, you are to directed to cut off the brown wire and set the dial on 1. We cut the wire, but neglected to reset the retard that is pre-set at 8. With a 8 setting, the retard is X 2 = 16 degrees! Woops...
We fought the carb all day Saturday as it got extremely lean above 4000 RPM (testing with AFR meter). Tried new PV's but no change.
I am think that the BIG backfire we incurred in May (with 16 degree retard) may have damaged the carb as we could not get it under control. Will have to wait and see what the Holley Custom Shop says.
We did swap the carb's on Sunday and the problem followed the carb...way lean above 4000 RPM.
Couldn't spend anymore time trying to figure this out as I we want to participate in LEOPA's July Poker Run.
06-22-2009, 10:30 AM
#32
Platinum Member
Platinum Member
Blue,
You were right, it was lean. Not sure this was the original issue that caused the backfire, but lean was surely the issue on our last trip. Holley found a small piece of debris in a needle and seat that was restricting flow; this carb was off 70 lbs at WOT.
We are back to "Go". We will replace the fuel/water separator filters to make sure they aren't the issue.
You were right, it was lean. Not sure this was the original issue that caused the backfire, but lean was surely the issue on our last trip. Holley found a small piece of debris in a needle and seat that was restricting flow; this carb was off 70 lbs at WOT.
We are back to "Go". We will replace the fuel/water separator filters to make sure they aren't the issue.
