TOPIC: Re-Set fuel trims, relearning ecu

Drove our 2002 Olds Silhouette with 3.4 Liter on Saturday approx 300 miles freeway. Had GM scan tool monitoring fuel trims and injector pwm mS's. Fuel trims both around 0 to pos 3-4.

Talked with Dan of Missouri. Reset ecu and fuel trims last night. Immediately, short trim -3 to -4 or more, Long trim -7 to -10 at times. Injector mS 3 to 6. I will continue to monitor, but things are looking up!

Scott Castleberg
Pellston, MI

Thats great Scott now they should remain there as long as some component is`nt faulty or slow to react. Attention all gadgetmen this is where we want to be monitoring as it tells you now if you cut fuel without having to drive the vehicles hundreds of miles let the customer do that they drive it anyway. Thanks Scott and keep us posted. Dan gadgetman Mo. Remember all alittle at a time.

Dan,
I have a 2004 chevy 5.3 pickup that has been grooved. I have blocked pvc, checked for vacuum leaks. Reset the computer per the instruction. Fuel trims are 3 to 5 short long 5 to 9 all plus. My mileage is still poor. Has any one improved with a 5.3?
Thank you
Dave
Chesaning Mi.

You said you reset the ecu did it read 0 long term fuel trims? If not it did not reset try again some ecus are alittle stubborn thats why we need a scanner to see figures. As soon as its reset start and check if it is drive easy 5 to 10 miles trying to get best mpg then shut off . Start again do this 3 to 4 times gradually then drive normal and the ecu should start to learn to cut the fuel back. As long as its pos nos it wont gain mpg. The fuel trims always tell the truth. These 5.3 and 6.0 will gain some 1 to 8 mpg better is what Ive seen some are stubborn. One thing Id like you to try is to get your speed up to 60 to 65 and just big toe pressure feel the engine float at less throttle pos this is where the best mpg seems to be from my experience. Do this after all the other has been done. This is the sweet spot and seems to get best mpg better than cruise as the cruise tends to go past the groove and not quite as good mpg. Dan gadgetman Mo. ps If you drive aggressive the ecu takes much longer to learn as it has to come from plus 20 down to neg 5 or so.

Dan,
I will try the reset again. This is one that I sent in to have a groove put on.
Thanks,
Dave