Sync? What is that???

So you moved your distributor or changed cams and now the truck is running strange? What gives? Can I just throw my timing light back on my 92-2003 318 and reset it? Must be the tune right???
Not just no.....
Moving the distributor does not change your spark~that's right, does not change it. What you do change is WHEN your injectors fire. The time is called cam sync- which is related to your crankshaft position sensor. You can imagine what happens if your intake valve has just closed and then your send fuel in the runner. You just missed your cylinder fill window for that cycle. Underneath the distributor is a gear driven by your camshaft called the oil pump driveshaft. That's right, it is what turns the oil pump downstairs and the distributor upstairs. When moving that oil pump driveshaft by changing cams, it has to be set back up to properly fire your injectors. Once you have mechanically set the steps above, you can put a scanner such as a Matco, SnapOn or DRB to set the sync. It will display sync OK if it is between -8 and +8. In the performance world, we always set to +4 to throw the mix right as the valve is opening with velocity. No scanner though? Simply follow the clocking directions above and you will be super close. Here is a great article below that will help you understand further details: (although I may actually be the author from the Bionic Dodge days...)
Magnum Engine Distributor Removal, Replacement, Re-syncing
When the distributor is removed and replaced in the magnum (fuel-injected) engines, the distributor must be
synchronized to properly time the injector pulse (spray), similar to the ignition timing for the spark plugs. The
distributor does not control the spark timing that is controlled by the computer. When the distributor is re-installed you need to get the sync close enough to start the engine so you can get it properly synced.
If the intermediate shaft was removed, as when replacing the camshaft, it must be correctly positioned before the distributor is installed. The slot in the top of the intermediate shaft must be positioned so that the slot runs from an 11:00 o’clock to a 5:00 o’clock position when cylinder #1 is at TDC compression stroke ( if the shaft is straight front to rear that is the 12:00 o’clock to 6:00 o’clock position). Once the intermediate shaft is correctly in place, the distributor can be installed.
Bring the #1 piston up to top dead center (T.D.C.) on the compression stroke. Remove the #1 plug and you can feel pressure coming out of the plug hole on the compression stroke. Line-up the T.D.C. mark on the damper, with the “0” mark on the timing tab, on the timing chain cover.

Install the distributor so that the rotor is lined with the small notch in the plate that covers the top of the
distributor base. This mark will time the injectors to pulse close enough to get the engine started and run.
Proper final synching should be done with a dealer’s scan tool DRBIII or Snap-On Scanner. The information given here is based on those scanners. Other scanners may not read exactly like the Snap-On. Setting the sync using an ohm meter is not recommended or accurate.
Using a scanner, the idle is brought up to 1000 rpm, to reduce valve train fluctuations and the sync signal set to zero. Most of our cams can use 3-5 units advance/positive. Note: This advance setting is only applicable when using the Snap-On DRBIII Scanners. The units are not all the same on other scanners. If you do not have a scanner that can do this, then pay to have the dealership do this.
Some of the symptoms that the sync signal is incorrect, you will get back firing through the intake manifold; vehicle will not idle or you will get major detonation at light loads causing the vehicle to lose severe power over 3000 rpm.

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