drewactual hit the nail on the head. I would find out if they set the fuel sync correctly, or if they set it at all. Anytime the distributor is even moved, the fuel sync must be checked and corrected with a scanner.

Them checking the timing and stating it was "close enough to spec" to not worry about would concern me that they don't know how it operates and they didn't touch the fuel sync. Base ignition timing, and all timing advance is controlled by the PCM.

If fuel economy doesn't improve (calculate it by hand the old fashion way too), get your fuel sync checked.

 

ok heres a good question how do i get my fuel sync checked

 

Snap on tool does it.. slap it on and select fuel sync.. idle will raise to 1krpm, and the dizzy is twisted to dial it in..

With oe rig, the Injectors spray on the back side of a hot valve.. this cools the valve, as well as atomizes the fuel.. the pulse can be retarded about 4* to spray more into the cylinder, which makes better use of fuel.. if you've upgraded Injectors to four hole sprayers, you don't need the valve at all to aromize fuel.. you get better throttle response and a touch better economy..

If you upgrade cams, you gotta look at the cam specs and valve timing relationships, as well as experiment to get the best use of duty cycles and pulse rate..

You're running stock, no? If so.. set it at dead nuts 0*.. the engine speed has to be above 1krpm because sync bounces below that.. bring her to 1krpm to settle that bounce, and get accurate reading.. snap on tools have a function that does it auto, but if you or a mechanic has one that doesn't, make sure and raise the engine speed to that mark.