If you keep your Fiero long enough, eventually you will need to replace the harmonic balancer. The rubber bonding cushion between the hub and outer ring deteriorates and allows the outer ring with the timing mark to slip. The first effect is that it creates an erroneous timing position, and second, it's possible that it can move toward the engine and wear a hole through the timing chain cover.
Damper Doctor sells replacement Fiero balancers with the correct mark, but the most common replacement used is from the FWD 60* V6 engines and the 93-95 RWD 3.4 V6's. All these engines have their timing mark to the right side of the engine where the Fiero's mark is to the left side of the engine.
So, how do you correctly time a Fiero with the timing mark a half mile out of position? Well, you need to have a new timing mark cut. But how do you know where to cut it? Seems none of the automotive shops know. Using the old balancer as a guide isn't advisable because it probably has slipped.
One method is to place the new balancer onto the crankshaft and rotate the engine clockwise until the #1 piston reaches TDC. First, use a compression tester to be sure you're on the compression stroke. TDC is best identified by using a dial indicator inserted into the #1 spark plug hole. Rotate the engine until the indicator stops increasing and begins to decrease. Make note of the reading. Rotate the engine backwards a sufficient amount that the indicator doesn't move, then go forward again. You may want to do this several times in order to zero in on the exact TDC.
Once you've determined TDC, mark the 0* position of the stationary timing mark to the harmonic balancer. Remove the balancer and have your machine shop cut the new timing mark.
Another way is to measure from the timing mark of the new balancer. Orief of Pennocks has a good description of how it's done. He mentions 2.8 but any 60* balancer will work. And I quote:
Oreif (kopielski1714@wowway.com) MSG #4, 08-18-2004 10:08 AM
The harmonic balancers will fit for ANY 2.8L V-6. But as stated the timing marks are on opposite sides.
I am using a GM Performance Parts balancer. To use one you need to turn the engine by hand until the #1 cylinder is at TDC. You can get close by turning the engine until the distributor rotor is pointing to the #1 spark plug wire. Then look at the balancer. There should be a groove at about the 2:00 o'clock position. Get a good ruler and measure 4.600" to the left of this mark, Scribe a line and paint it white. This is the Fiero timing mark. You could also just mark the new balancer at all 3 places before you put it on (the balancers have a groove every 120*) Just mark a new line 4.600" to the left of each mark and it will line up for the Fiero timing scale.
GM Performance Parts also sells a performance balancer that has the outer ring pinned to the inner ring so it doesn't shift with age. It's available thru PAW or GM. The GM P/N is 14085401 (PAW uses the GM part number as well)
