Failure Injection Corsa

Hi Juan, initially I think you should rule out the ignition coil if you replaced it with a new one. Remove the injectors and use a multimeter to test the resistance of all four. They should be within the same range. I don't know the year of your truck, but I imagine it has an OBD2 diagnostic connector. I recommend using a scan tool to check the DTCs; it might show you if the injectors are actually failing. After that, use an injector tester to check if they are working correctly—specifically, spray pattern, leak tightness, and fuel flow rate.
I hope this helps. Sincerely,
Mauricio Veloso

Hi, what Oliva Muñoz says is correct. Be careful when measuring the voltage to the injectors, as they are constantly powered by 12V+ and the ECU activates them with ground (-).
If you want to test the ECU's negative signal, I have a cheap and easy way for you to do it: with an LED and a 1.5 kΩ resistor. Solder the resistor to one of the LED's legs, then disconnect each injector. Connect the two remaining LED and resistor terminals to the connector coming from the ECU. Note the LED's polarity; it has a flat part at the waist that would be negative. Then, have someone start the engine and check if the LED blinks. If it does, then the ECU is sending an injection signal.

But look, in my opinion, the problem is simpler than it seems. Check the spark plugs. If they have what mechanics call flashover, which is scratches on the ceramic part where they're losing current, the spark plug might be in good condition, its electrodes might be fine, and it might even be new. But when flashover occurs, it causes these jerks, with an unstable idle and loss of power. It can even increase your fuel consumption. This problem is caused by spark plugs with an incorrect heat range, engine overheating, engines equipped with LPG/CNG, and also faulty wires. I don't know the version of your engine, but if you have an ignition system with high-tension wires, I recommend that you also check their resistivity. In my experience, they shouldn't exceed 10 kOhms. Test them, especially when they're hot, since that's when they cause the most problems.
I hope I've been able to help you a little. Good luck with your repair.

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