However $200 is a fair amount of money. So if a meter is out of budget as IDIBronco shared don’t do one and done, try 3 settings a dimes width of each other via the pump alignment marks. Find the spot that has good starting, good mpg, and good power. You are likely now 2-4 degrees from spec.
It's all good advice.
But it should be the THICKNESS of a dime. Not the WIDTH of a dime.
I doubt if your engine will blow up if you change the timing by the width of a dime, but it can't be good for it, to have the timing out by that much, (if you go that far in the wrong direction.), and run it.
Follow Bart's instructions but only go the thickness of a dime.
Once you have moved one direction or the other and found an improvement, keep moving one thickness of a dime at a time, in that direction.
It will reach a point where it will start to get worse again. Stop there and go back one thickness, if you have only moved two or three thicknesses total from the original starting point. If you have gone further, you may have to back up twice.
That's how I set my timing by 'gut feeling'. (Not as much by just ear, as by ear plus overall gut feeling.)
I get 15+ mpg. When I first got the truck I was lucky to get ten.
I get white smoke when I first start it up. (Not much, and it stops very quickly.) And the only other time I get smoke is a tiny puff of black smoke if I really put my foot into it fast and hard, on an incline or to keep up with traffic. It doesn't even keep smoking if I keep my foot into it.
Between the MPG, black smoke, white smoke, seat of the pants dyno, smoothness of running, and overall just gut feeling, I believe I have it set pretty close.
I will add that when mine started to run rougher, less mpg, seemed to start to dog it a bit... I replaced the fuel filter. Filled the new one with ATF. Ran the engine until I was good and sure the IP and injectors were all full of the ATF. Turned it off, and let it set for more than 24 hours.
It was a bit of a 'different' start on the ATF, on that first start after, but man, it ran great after that! Ran smooth. MPG was back, etc.
I did this again, a few days before I replaced my injectors, recently.
