misterp Posted July 23, 2005 Report Share Posted July 23, 2005 Quick question for experienced PCM guys - I got some bad gas yesterday, fortunately only 3/8-tank. I refilled today at another station, the truck runs smoothly now but is down on throttle response, so am I right suspecting that the PCM needs time/mileage to reset fuel trims and advance? If so, how long or how many miles until the PCM 'optimizes' its tune? I need to know because I want to run 1/8-mile tomorrow! Thanks in advance - Mr. P. Quote Link to comment Share on other sites More sharing options...
d_a_n_payne Posted July 23, 2005 Report Share Posted July 23, 2005 Im not sure but I dont think the pcm needs any time to reset, just time for the bad gas to flow through Quote Link to comment Share on other sites More sharing options...
infinus Posted July 23, 2005 Report Share Posted July 23, 2005 The PCM has a low octane mode. Zippy mentioned something about it resetting everytime you fill up or every 50 miles or so or something like that, but I'm not sure on that. He'd know best. Quote Link to comment Share on other sites More sharing options...
TimC3 Posted July 23, 2005 Report Share Posted July 23, 2005 That sounds right, but yeah.. Zippy? your Final Answer? Quote Link to comment Share on other sites More sharing options...
zippy Posted July 24, 2005 Report Share Posted July 24, 2005 there are a few variables that wil reset this. it will retry to start again on the high octane table after a certain number of miles or warm up cycles. i believe it's somewhere around 50. if you run the tank low though i believe it will also attempt after it see's the fuel level change as it would in a fill up. this along with evap system tests is why the fuel level was added to be run through the pcm. Quote Link to comment Share on other sites More sharing options...
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