How to Replace the Distributor in a Pontiac Grand Am

The sporty Pontiac Grand Am went entirely distributorless with the 1999 models. For its 2.3L and 2.5L engines in earlier years, Pontiac used a High Energy Ignition (HEI) system that had a Direct Ignition System. Here's how to replace the distributors for the Direct Ignition System (DIS) in 2.3L and 2.5L engines with some basic tools.

Instructions

1

Trace the spark plug wires to the distributor cap on top of the DIS assembly. Depending on your model and year, you may find the distributor on top of the engine or on the bottom of the engine between the engine and the firewall. If it's on the bottom, you'll have to lie on top of the engine to get at it.

2

Unhook the negative cable on the battery. Unbolt and unscrew all electrical connectors to the DIS distributor assembly with a screwdriver or wrench, as necessary; label them so you can put them back in their proper place. Also label and disconnect the spark plug cables from the coils.

3

Take off the distributor cap by removing the screws or clamps and remove the distributor clamp screw/bolt and the hold-down clamp.

4

Mark the rotor position with a line on the distributor housing. This will help you replace it correctly later. Pull the distributor up until the rotor stops turning counterclockwise, and mark the rotor position. The shaft will rotate slightly as you remove the distributor. Finish taking the distributor out of the engine block.

5

Use a breaker bar (long-handled ratchet) to rotate the shaft until the rotor lines up with the second mark you made.

6

Fit the DIS distributor assembly for your Pontiac Grand Am into the engine. You can order distributor AST20-2120 for 2.3L and 2.5L engines from 1990 at Parts Train (see Resources). As you install it, the rotor should line up with the first mark you made during Step 4. This will create proper timing for your engine. If the marks don't match properly, remove the distributor and try again.

7

Bolt down the retaining bolts and replace the distributor cap. Reconnect the spark plug wires to the coils and reattach all DIS electrical connectors, paying attention to the labels. Hook up the negative battery cable.