1989 Buick regal 3.1 won’t start when engine warms up

1989 Buick regal 3.1 Car runs fine for 10 minutes. If you shut it off it won’t restart but it will turn over. It has spark to all six plugs it has gas pressure of 45psi. Changed ECM and ignition module. If I wait for to cool off it will start again. Idle position sensor and throttle position sensor both work. Additional question; can the antiknock sensor cause this or possible grounding of hot lines wires to the injectors located under the intake plentum?

Answer: If it has spark, there was no need to change the ignition module. Idle and throttle sensors will not cause a no start.

Sounds like you are loosing fuel injector pulse signal. This is usually an ECM problem, since it controls the ground side. You need to check for power to the injectors also. Most likely you have 1 or even several bad feul injectors. This causes the ECM to not fire all of them.

You would need to remove the upper plenum and use a meter to check the ohms of each fuel injector. They should be about 12.5 ohms. Any less will cause your problem.

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