1989 Plymouth Voyager starting

Hi carsandtrks5. Welcome to the forum. Since you have spark, that leaves out a lot of stuff including whatever sensors are used depending on which engine you have. When it doesn't start, check for fuel pressure. The 3.3L has a test port on the fuel rail. It looks exactly like a tire valve. Pressing the valve should cause fuel to spray up to the hood for a fraction of a second. If it does not, suspect a stalled fuel pump. Banging on the bottom of the fuel tank while a helper cranks the engine will often get it started. Once it's running, it will rarely quit while driving. They almost always fail to start up. Be aware though the pump should only run for one second after turning on the ignition switch, then it will turn off. It must start running again during engine rotation, (cranking or running).

Another fast way to check for worn brushes in the fuel pump motor is to pop the cover off the fuel pump relay, reinstall the relay, then watch very closely for a tiny spark at the contacts when you squeeze them. Lack of a spark means there is no current flowing to the pump, possibly due to a burned electrical connector terminal at the pump, but more likely due to worn brushes in the motor.

Caradiodoc

Which engine do you have?

Caradiodoc

Yup. If it has spark, the Automatic Shutdown (ASD) relay is working properly. That's why it just leaves the fuel pump or injector circuit.

I had a similar problem with my '88 Grand Caravan 3.0L right after I washed the engine. Turned out to be corroded pins in the electrical connector between the throttle body and brake master cylinder. It only feeds the injectors, not the ignition coil. All I did was unplug it and plug it back in. The scratching action on the terminals was all it took to clean them up. I haven't touched it since, and it is still my rusty trusty daily driver.

Use a cheap digital voltmeter to measure the voltage on one of the injectors. There should be 12 volts there for one second after turning on the ignition switch, and always during engine cranking. If it is missing, there is very little that can be the problem. The feed wire goes back to the ASD relay which we know is working.

Caradiodoc