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View Full Version : Previa Fuel Injector timing


stevenmarquis
Jan 23, 2018, 11:39 PM
I had a couple stuck on injectors, which I just replaced, but I placed an O-Scope on the injector wires and found during start cycles that the injectors were turned on rather than pulsing. That sounds bad. The I reviewed, the firing order which is listed as one cylinder firing at a time, yet the schematic shows pairs of injectors ganged together. How can that possibly work?

It seems like the ECU is not sending the right signals but basically I cant understand how it could ever work with the injectors so ganged. Can anyone add some enlightenment?

smoothy
Jan 24, 2018, 05:39 AM
That is what I understand to be called " Batch fire" where you will have multiple injectors fire at same time vs a true sequential with only one injector at a time. Like you said, if it was really out of whack, it would not run well. You can get away with it because they aren't direct injection, engine ingests nothing until the valve opens.

Originally limitations were technological in nature, then it became more cost vs results....now technology and cost is much less an issue and results (power, economy and emissions) are what drive it principally.