It appears that high temperatures that build up near the distributor can
cause the pick up coil on the Fiero V-6 engine to literally burn up. This may
be caused by the EGR valve tube going into the intake plenum being located so
closely to the distributor. In some cases, the pick up coil has shorted out in
20,000 to 30,000 miles. It would be recommended to replace the pick up coil at
30,000 mile intervals, as preventive maintenance, when you change your
distributor cap, rotor, and sparkplugs. Keep in mind that if the pick up coil
shorts out, your V-6 Fiero will stall out and will be difficult, if not
impossible, to re-start - leaving you stranded.
The pick up coil is located at the base of the distributor and plugs into
the ignition module. The pick up coil's purpose is to sense or "pick up" the
pulses of the distributor and tell the ignition module when to fire the spark
plugs. The most critical part of the replacement of the pick up coil is to
make certain you properly mark the orientation of the distributor to the
engine block and the rotor to the distributor base. When you successfully make
these markings, you will not need to check your timing when this job is
finished. Keeping this in mind, here we go:
You will need to purchase a replacement pickup coil and a rubber o-ring gasket
that will replace the o-ring located where the distributor shaft enters the
engine before you start this project.
The GM part numbers are:
 | 1987972 - ignition module hold down screws - (2) cost is $.75/ea. |
| 10475880 - distributor shaft rubber "O" ring - (1) cost is $.75/ea. |
| 10495089 - pick up coil - (1) cost is $12.85/ea. |
- Unplug the ignition coil wiring - which is the spark plug wire leading from
the coil to the center of the distributor. Also, remove the two wire connectors
that plug into the ignition coil itself. Now, remove the ignition coil by
removing the two 13mm mounting screws.
- Unscrew the two mounting screws on the distributor cap using a Phillips
screwdriver or 7/32" nut driver and move the distributor cap away from the
distributor - you do not have to remove the spark plug wires from the
distributor cap if you do not want to - there will be enough room to work.
- Disconnect the two plug connectors from the ignition module located at the
base of the distributor. Remove the ignition module from the base of the
distributor by loosening the two 7/32" mounting screws. Be sure that these
mounting screws are not corroded because they provide the ground for the
ignition module. Replace if necessary. Now, unplug the pick up coil connector
from the back of the ignition module.
- Using a 15mm socket, remove the bracket at the base of the distributor
that holds the distributor to the engine block.
- Where the distributor enters the engine, place a fine mark with paint
(quick drying) or an etching device to orient the distributor base to the
engine block so your engine timing remains the same when you re-install the
distributor.
- Now you need to make a mark to orient the distributor rotor. Place a mark
to orient the protruding prong of the rotor to a fixed point on or near the
engine. Again, doing this assures the engine timing will be the same now as
when you replace the distributor when you are done.
- Remove the distributor by pulling straight up on the distributor - there
could be some resistance depending on how well the O-ring gasket is seated.
Take notice that the rotor turns as you are pulling up on the distributor.
Mark a third orientation mark where the protruding rotor prong stops turning
as it is released from the internal gear in the engine. You will use this
reference point to position the protruding rotor prong as you are replacing
the distributor into the engine. Move the distributor base around the throttle
body coolant lines to remove the entire distributor from the engine. Patience
is a virtue!
- With the distributor removed from your Fiero, place it on a work bench and
examine the orientation of its parts so your re-assemble it correctly.
- Notice near the bottom gear on the distributor shaft is a roll pin
(Approx. 3/16" dia, 1/2" long) which holds the distributor gear to the
distributor shaft.
- Place the gear end of the distributor on a solid metal surface, like the
heal of a bench vise -not in the vice itself because you do not want to damage
the distributor gear or shaft. Using a hammer and the 3/16" die punch, remove
the roll pin from the shaft of the distributor. Remove the distributor gear
from the gear shaft - note the orientation of the lock tab washer as you remove
the distributor gear.
- Slide the distributor shaft out of the distributor base. Clean and polish
the shaft to create a clean, burr-free, polished surface using steel wool or
mild sandpaper. Lubricate the shaft with motor oil. Set aside.
- Remove the rubber O-ring gasket near the bottom of the distributor base
and replace it with a new one to prevent oil leaks. Lubricate the O-ring with
motor oil to correctly seat the gasket.
- Now it is time to remove the pick up coil from the distributor base.
Remove the pick up coil retaining clip from the top of the distributor - be
very careful not to pry up on the retaining clip as this will damage the
distributor base. It is best to cut off this retaining clip to prevent damage.
Note the orientation of these parts as they are removed from the base. Note
how the pick up coil is positioned on the base. There are alignment pins on
the bottom side of the pick up coil to orient it to the distributor base.
Be sure to follow the directions that came with pick up coil to ensure proper
replacement.
- Replace the pick up coil on the distributor base along with the spacer and
retaining clip. Make sure the pick up coil alignment pins are properly
positioned on the distributor base.
- Replace the oiled distributor shaft into the distributor base.
- Replace the lock tab washer and the distributor gear on to the distributor
shaft. Reinstall the roll pin using the 3/16" die punch.
- You are now ready to replace the distributor back into the engine block.
Place the protruding prong of the rotor at the orientation mark where the rotor
stopped turning as you removed the distributor. Push down on the distributor
making sure you are engaging the gears on the distributor shaft with the gears
in the engine. Continue pushing down until the O-ring is properly seated in
the engine block. Verify that the protruding rotor prong is oriented with the
first orientation mark you made. If they do not match up, remove the
distributor from the engine block and try again until they do line up in order
for the timing to be properly set.
- Now that you have the rotor correctly oriented, the base of the
distributor needs to be re-oriented to the engine block. Make sure your
alignment marks are oriented properly and replace the distributor base hold
down bracket and screw - be careful not to move the base off of the
orientation mark.
- Now, remove the old coating of di-electric grease from the bottom of the
ignition module. Re-mount the ignition module onto the distributor base after
applying a new coating of di-electric grease onto the bottom of the module.
- Connect the pick up coil to the ignition module after applying di-electric
grease onto the bottom of the pick up coil connector.
- Replace the distributor cap onto the distributor.
- Replace the ignition coil.
- Re-connect the wiring to the ignition module.
- Re-connect the wiring to the ignition coil.
- Start your Fiero to make sure all the proper connections have been made
and your timing remained accurate. If all is done correctly, your pick up coil
should last another 30,000 miles, if not more.
Keep an eye on the pick up coil and check it when you check your spark
plugs or distributor cap or rotor. Add the pick up coil to your list of
routine check and replacement procedures. If you do not, you could surely be
stranded sometime in the middle of nowhere. It would be advisable to keep an
extra pick up coil in your Fiero at all times. If you do, you can always find
a local garage to pull the distributor for you - at least you know you have
the part in stock!
From: Jim Hallman and Paul Vargyas
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