gmachinz
08-20-2008, 01:50 PM
Okay, dealing with a 4.6 Ford motor with a 76mm single turbo and the factory engine management has been eliminated altogether. At idle, the A/F ratio gauge sweeps between 6:1 and 18:1 while the idle goes up/down respectively for the changing ranges, then after about 20 seconds, the motor smoothes out and idles fine with about a 13:1 ratio, then after 30-45 seconds, it starts all over again I'm starting to think possibly the wideband O2 sensor doesn't like the 112 octane fuel. The car does this at idle and part throttle/cruising but not at WOT. Any thoughts? I've never seen this before.