Distributor timing issue?

This is how the book says to do the timing. Can I ask if the engine was running the same way with the old distributor?

IGNITION TIMING ADJUSTMENT
WARNING: To prevent possible personal injury from a moving vehicle or operating engine, do the following before performing the checks:

Engage the parking brake and block the wheels.
Place the transmission in neutral.

1. Refer to the Vehicle Emissions Control Information label under the hood. Always follow the Vehicle Emissions Control Information label procedures first before using the following procedure.

2. Put the IC system in the bypass mode by disconnecting the "set timing" connector. This is a single wire sealed connector that has a tan with black stripe lead. This connector breaks out of the wiring harness below the heater case in the passenger compartment.

3. With the ignition switch "OFF, " connect the pickup lead of the timing light to the number one spark plug. Use a jumper lead between the wire and plug or an inductive type pickup.

DO NOT pierce the wire or attempt to insert a wire between the boot and the wire. Connect the timing light power leads according to manufacturer's instructions.

4. Start the engine, and aim the timing light at the timing mark. The line on the balancer or pulley will line up at the timing mark. The timing should be O° TDC. If a change is necessary, loosen the distributor hold-down clamp bolt at the base of the distributor. While observing the mark with the timing light, slightly rotate the distributor until the line indicates the correct timing. Tighten the hold-down bolt, and recheck the timing.

5. Turn "OFF" the engine and remove the timing light. Reconnect the number one spark plug wire, if removed.

6. Reconnect the "Set Timing" connector.

Preassembled replacement distributors are not available. Components are available to assemble a new distributor. Some components, such as the air cleaner, may need to be removed to reach the distributor. The distributor has a separate ignition coil that mounts to a bracket on the top of the engine.

REMOVE OR DISCONNECT
Make sure the ignition switch is "OFF."

1. Air cleaner and hoses.
2. Electrical connectors at the side of the distributor cap.
3. Two screws on the sides of the distributor cap.
4. Ignition coil wire and spark plug wires on either the left or right side of the distributor.
5. Distributor cap and move it aside.
A. Use chalk to note the position of the rotor in relation to the engine.
B. Use chalk to note the position of the distributor housing in relation to the engine.

6. Distributor bolt and hold-down clamp.
7. Distributor.

INSTALL OR CONNECT
1. Distributor.

A. To ensure correct timing of the distributor, it must be installed with the rotor correctly positioned as noted in step 5 of the removal procedure. Line up the rotor to the mark on the engine, and the mark on the housing to the engine.
B. If the distributor shaft won't drop into the engine, remove the distributor, insert a screwdriver into the hole for the distributor and rotate the oil pump driveshaft so it lines up with the distributor drive gear.

2. Hold-down clamp and bolt.

Tighten
Bolt to 27 Nm (20 lbs. In.).

3. Distributor cap with two screws.
4. Wiring harness connectors to the sealed ICM connectors at the side of the distributor.
5. Spark plug wires and coil wire.
6. Air cleaner and hoses.
Check the ignition base timing.

Please go over this guide and get back to us.

That's a good one I have seen engine coolant sensors short out when cold. Let's run the codes to see what is stored.

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

Please go over this guide and get back to us.

It sounds like the cat might be clogged or the fuel pump is going out.

This guide can help with testing the catalytic converter:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

This will help test the fuel pressure:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Ignition ON Engine OFF .................... 62-90 kPa (9-13 psi)

Please go over these guides and get back to us.

I have seen the distributor gear roll pin shear and allow the gear to "slip" on the shaft changing the timing, or you have a bad PCM.

There is a roll pin at the bottom of the distributor gear which can "shear" allowing the gear to slip on the shaft which will change the timing. Just to confirm you say the timing changes after you run it, correct? For the PCM you will need to send it in for testing.

Did you have this problem before the new distributor install? If not, it sounds like you may have gotten a defective unit. Does the engine seem to run okay without timing wire connected?

Can I ask which brand you purchased? I have seen bad pick-up coils, modules and main ignition coils cause this problem.

Anything?