jrd Posted December 11, 2007 Share Posted December 11, 2007 Hi all, I am still having trouble with my Megasquirt setup on my 70 240Z. I am just running injector control and I swear, if I wasn't planning a turbo upgrade the SUs would be back. I still have lots of trouble starting it. I have to depress the pedal slightly and if that doesn't work I have to hold it on the floor. Also, when I am driving at a constant speed it feels like someone keeps tapping the brake pedal...I guess this is the opposite of surging. It does it under slight acceleration as well. On hard acceleration it doesn't do it. I am posting all my tables - any help would be much appreciated. This is a l28 that is bored out 30 over with the standard injectors without the dropping resistors. Nothing else special. Thanks! Joe Quote Link to comment Share on other sites More sharing options...
Thumper Posted December 11, 2007 Share Posted December 11, 2007 What is your a/f ration doing? Also I usually run my injectors alternating not simulataneous. By the way you have your settings you are running a flyback board correct? Quote Link to comment Share on other sites More sharing options...
ktm Posted December 11, 2007 Share Posted December 11, 2007 Also, when I am driving at a constant speed it feels like someone keeps tapping the brake pedal...I guess this is the opposite of surging. It does it under slight acceleration as well. On hard acceleration it doesn't do it. You are lean surging, that is to say, your fuel map while cruising is too lean. Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted December 11, 2007 Share Posted December 11, 2007 Your cold starts might be set too high, which is why you flood the engine, and then start it by flooring it (which sets it into flood clear mode, no fuel injected). If your TPS is too sensitive you could be triggering accel/decel enrichments making the cruise and slight accel choppy. Mario Quote Link to comment Share on other sites More sharing options...
jrd Posted December 12, 2007 Author Share Posted December 12, 2007 What is your a/f ration doing? Also I usually run my injectors alternating not simulataneous. By the way you have your settings you are running a flyback board correct? I am pretty sure that flyback was built into this board, so yes. I am not sure about the a/f ratio.... to the right of center means too much air (a large f small)? joe Quote Link to comment Share on other sites More sharing options...
Thumper Posted December 12, 2007 Share Posted December 12, 2007 I am pretty sure that flyback was built into this board, so yes. I am not sure about the a/f ratio.... to the right of center means too much air (a large f small)? joe Sounds like you are using a narrowband to tune. A narrowband is only accurate for 14.7 +or- 0.5 I would highly recommend a wideband asap. But with what people have said sounds like its a good start. Quote Link to comment Share on other sites More sharing options...
jrd Posted December 12, 2007 Author Share Posted December 12, 2007 Sounds like you are using a narrowband to tune. A narrowband is only accurate for 14.7 +or- 0.5 I would highly recommend a wideband asap. But with what people have said sounds like its a good start. What is involved in switching to a wideband O2 sensor? I have had people tell me that that would help me run closed loop...do you have a link or parts list? For now, I think that I am running too lean. I will increase my required fuel value - that should effectively up everything across the ve fuel table, shouldn't it? Thanks, Joe Quote Link to comment Share on other sites More sharing options...
dum-bass Posted December 16, 2007 Share Posted December 16, 2007 What do you have your o2 authority at? The reason I ask, is that if you have it set to say 10 and your ve table is slightly off from your o2 target, then you will feel a slight surge. If it is set to say 50, then the surge will feel substancially worse which should tell you where to fatten or lean your ve table. What I do is drive with the ve tuning table on and hit the F key when I feel the surge and fatten or lean that point till it evens out. I am a total noob to megasquirt but I think this method works well. Quote Link to comment Share on other sites More sharing options...
jrd Posted December 16, 2007 Author Share Posted December 16, 2007 What do you have your o2 authority at? The reason I ask, is that if you have it set to say 10 and your ve table is slightly off from your o2 target, then you will feel a slight surge. If it is set to say 50, then the surge will feel substancially worse which should tell you where to fatten or lean your ve table. What I do is drive with the ve tuning table on and hit the F key when I feel the surge and fatten or lean that point till it evens out. I am a total noob to megasquirt but I think this method works well. I completely don't understand this. What is the o2 authority and how do I set it? Thanks, Joe Quote Link to comment Share on other sites More sharing options...
jrd Posted December 16, 2007 Author Share Posted December 16, 2007 OK, I upped some of the settings in the VE table and the surging got much better, but still not completely gone. One issue that got worse was I now have an incredible backfire between shifts. What knob to I adjust to get rid of this. Can anyone direct me to some settings that someone knows work for a NA L28? Also, how do I set-up a wide band O2 sensor - any links? Thanks, Joe Quote Link to comment Share on other sites More sharing options...
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