boostin280zx Posted March 4, 2006 Share Posted March 4, 2006 Alright, I had a really good tune with the stock injectors. It would rev up really quick and smooth with no sputter or delay. The fuel and spark maps were really good but started to lean out if i turned the boost up to around 15psi. I am running ms2 on the v3 pcb and have a lc1 wideband. I just installed some rc engineering 550cc/min injectors with a sx regualotor set to 43psi. My car wants to idle at a a/f ratio of 7.0 to 10.0. Ive tried leaning out the ve and afr tables and putting in bigger injector sizes to see if it would lean it out a lil but nothing really helps. The only thing that will bring it up to a 14 to 15 a/f is messing w/ the injector opening time. When i change it from 1ms to .8 it gets the right amount of gas but sputters when i try to rev it up. When i was reading up on megasquirt before i decided to build one awhile back i remember reading something about tricks for tuning. Stuff like messing w/ the injector characteristics to get a good idle but can't seem to find that site anymore. (my car idles really good, just dosen't like to rev smooth or drive as smooth.) Has anyone tuned a l28et w/ 550's before and should i still be able to use my ignition map for my stock injectors since that one worked really well with the stockers? Quote Link to comment Share on other sites More sharing options...
technicalninja Posted March 5, 2006 Share Posted March 5, 2006 Do you have a Vacuum controlled regulator? If not, a regulator which varies fuel pressure in responce manifold pressure (vacuum) would lower your fuel pressure at idle (high vacuum condition) and allow you to increase your pulse width. 1 ms seems to be the limit of some fuel injectors. Not enough time to fully activate the injector before pulse is cut. You might want to contact RC Engineering to find out their suggestions of a minimum pulse width for your injectors, set the MS to that figure, and then adjust fp to reach your AFR. Quote Link to comment Share on other sites More sharing options...
boostin280zx Posted March 9, 2006 Author Share Posted March 9, 2006 Would it be easier to lower the fuel pressure to 23psi so the injectors would only be about 400cc/min injectors? I have a rising rate fpr btw. Would it be alright to only have 23psi. And one more thing iv'e been wondering... If megasquirt knows the injectors size and knows how much fuel to squirt at what rpm and kpa, could I just take the vacum line off the fpr to keep it a constant fuel pressure and just make sure it is going to be rich enough on my fuel maps?? Quote Link to comment Share on other sites More sharing options...
clint78z Posted March 9, 2006 Share Posted March 9, 2006 Reduce idle timing and open throttle blade bypass screw more. This will allow you to run leaner with that same amount of fuel. Quote Link to comment Share on other sites More sharing options...
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