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sequential injector timing

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Hello to all. ecu vipec v88 link g4 mounted on 1800 cc cc watercraft 4 cyl engine, I have three similar basic maps, there are three differences on the sequential injector timing chart, someone explains this function to me, and what are the advantages and disadvantages of these two. thank you all

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Injection timing is the angle (0-720 degrees for 4-stroke engines) that the injectors will either start to open, or close (most ECUs have a setting for this, close is the more typical choice). There are many different theories, some want to have the injector spray while the valve is open, and some want to spray on a closed intake valve (manifold pressure is more constant, and fuel vaporizes better on the hot valve). The larger the injector (relative to engine displacement) the shorter the injection pulse will be and the more the injection timing will make a difference (especially at high load/RPM). An engine with an injector that is open 85% of the time doesn't see any change due to injection timing.

So Injection Timing is a parameter that you tune to give the engine what it wants. Sometimes this is difficult to tell. What you do is watch what happens to the Lambda/AFR values when you make changes. Anything that results in a richer mixture, means the same amount of fuel is being used more effectively, so you want to adjust until you have the richest mixture at each RPM. After that, be sure to revisit the fuel table to get the mixtures back on target.

BTW -- the one with the injection angles from 375-475 deg would be typical based on my experience.

thanks for the advice detailed explanation; really appreciate your kindness.

Best regards, Lorenzo.

Glad you found it useful. Happy to help.

Hi Lorenzo, here are a couple of webinars that cover injection timing:

https://www.hpacademy.com/previous-webinars/061-optimising-injection-timing/

https://www.hpacademy.com/previous-webinars/111-injector-timing-haltech-elite/

hello thanks, andre, I saw the two webinars. I'm excited to learn about this platform, the only problem that many videos lack subtitles. I'm Italian and I'm not good with English, as long as I read it all right, but if I just have to listen to it, it gets a little difficult for me, I take the opportunity to ask if someone could find me a place where I can come a couple of months for learning English in return I could work for free I am a good mechanic. I would be free of my job for January February, the watercrafts are still in winter and I am free. bye thank you