You should try to find a Factory Service Manual but the following might be enough to help isolate your problem.
Step 1.
Check the EGR valve for functionality. When the engine is cold remove the vacuum tube at the EGR valve.
Put a vacuum pump on the EGR valve and lower the vacuum to 16 inches.
Does the vacuum hold steady?
If NO you have a hole in the EGR diaphragm.
If YES did the plunger under the EGR valve move?
Put a vacuum gauge on the line you disconnected from the EGR valve. Start the engine. When the coolant temperature gets above 53 C the Thermal Vacuum Valve should start to allow manifold vacuum to move the needle of the vacuum gauge.
Does the engine continue to run now?
If YES, problem with EGR valve.
If NO.
Step 2.
Put a fuel pressure gauge between the fuel filter and the fuel rail.
Put an inductive timing light on the # 1 spark plug.
Drive the vehicle until it stops.
Do you still have spark (timing light blinks)?
Do you still have fuel pressure?
Step 3.
When the engine is cold, start the engine and then remove the electrical connection to the Cold Star Valve.
Does it still run?
Please report back your results.
Wayne Monteath
Masham, Quebec.
