osirus9 Posted April 17, 2015 Share Posted April 17, 2015 You're running resistors for each of those low impedance injectors right? Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted April 17, 2015 Author Share Posted April 17, 2015 You're running resistors for each of those low impedance injectors right? Of course not. I am using PWM so I can open them quickly with full voltage and hold them on with a lower voltage. Using resistors with low impedance injectors is defeating the purpose of having them. I have done some re-wiring. I added some tantalum capacitors across the PWM circuits, and the 12V is pretty stable even during PWM, I get maybe 0.5V of variation. I also routed the grounds for the injector MOSFETs directly to the DB37 connector. The periodic missing is decreased, as a matter of fact it's completely gone until the engine reaches operating temperature, but it still kicks in. I don't know yet how I am going to fix this. When I get time, I will continue to probe the signals with my scope to see if I can pinpoint the issue. It's a huge pain in the a$$, I certainly did not anticipate this level of difficulty with what's supposed to be a developed product. Quote Link to comment Share on other sites More sharing options...
osirus9 Posted April 18, 2015 Share Posted April 18, 2015 Alright alright, I know that low impedance injectors are a tiny bit faster than high impedance. I was just making sure you didn't wire them straight into the MS like you would with high z injectors. That'd be a good way to run too much current through your board. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted April 20, 2015 Author Share Posted April 20, 2015 Alright alright, I know that low impedance injectors are a tiny bit faster than high impedance. I was just making sure you didn't wire them straight into the MS like you would with high z injectors. That'd be a good way to run too much current through your board. I do appreciate your feedback. You are right, I suspect the weak points in this ECU design are related to current, and with 6 low impedance injectors I may be pushing its capabilities. I might be able to fix this whole damn thing by simply adding resistors and killing the PWM - I hate to admit defeat, but reality does not care about my ego. Quote Link to comment Share on other sites More sharing options...
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