Intermittent power failure on nozzles 2 and 4, codes P0302 and P0304

Welcome to 2CarPros.

If you are losing the signal to the injectors, have you checked the wiring between the injectors and the ECM? Have you checked the main connection at the ECM? There could be corrosion, a damaged pin, or a broken wire. I attached a portion of the schematic for you. Disconnect the battery before doing this work and then make sure the ECM is connected before you reconnect the battery.

The ECM is behind the right side of the dash. You need to check pins 3 and 5 to see if they are damaged in the connection. Also, if you find you lose the injector pulse, check right at the ECM to see if the pulse is there.

Let me know what you find. Also, keep in mind, there is a common brown wire that runs between the injectors as a ground. Each injector is spliced to that ground, so make sure nothing there is loose or corroded.

As far as the crankshaft position sensor, both it and the camshaft position sensor play a role in ignition time as well as injection timing. When a crankshaft sensor begins to go, usually the vehicle will stall when warm, be hard to start or fail to start warm. Here is a link that explains symptoms:

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

I mentioned that sensor because it may fail and not set a code.

As far as the injectors, if you look at pics 2 and 3, it shows how to test them to confirm there isn't an issue with those specific injectors. Basically, you are checking resistance.

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I hope something here helps. Let me know what you find or if you have other questions.

Take care,
Joe