pdkoch Posted February 26, 2011 Share Posted February 26, 2011 hey i have a 240z with an L28et swap with forged pistons and 325cc injectors running a full megasquirt ECU swap rest of the engine is pretty muuch stock besides a BOV and FPR and Walbro my car keeps going lean above 3psi stock injectors are 285cc so? we are trying to tune the car but cant since it keeps going lean on the dyno even if the tables are maxed out. when we try and use the Autotune from Tunerstudios it creates mountains in the table very strange. I dont know if its a Fuel delivery problem or something to do with my megasquirt setup like the settings are set up wrong in Tunerstudio's, also the ecu is heating up Thanks any and all feedback would be greatly appreciated Quote Link to comment Share on other sites More sharing options...
dexter72 Posted February 26, 2011 Share Posted February 26, 2011 Are your injectors to small?. Check fuel pressure and under a load?. I put 315cc injectors in my turbo engine after adding megasquirt and I couldn't tune it past 3500 rpm. After installing 440cc injectors my problem went away. Quote Link to comment Share on other sites More sharing options...
stprasinz Posted February 27, 2011 Share Posted February 27, 2011 I had a simlar symptom... No matter how I punched in the ve tune setup (just to get te idea where to start) I would lean out alot above somewhere in there.. I had to estimate the hp to be ALOT higher then I thought and still same thing. And the low end of the tune was WAY to rich.... I started tuning by at 100 (mine is actually 101) I pulled 1 away and triangled back, 1 row less vaccum , and one row less rpm pulling 1? in every step... Then I did the opposite in + side. I then tuned it from the wide band That should get you able to run though.... Quote Link to comment Share on other sites More sharing options...
CamH Posted February 27, 2011 Share Posted February 27, 2011 (edited) What are you running as far as fuel lines? Is it possible that you have a fuel line blockage? Check your filters! Also, go get a fuel pressure gauge and put it on there. For a while, I was running 10psi with my car on STOCK injectors with MegaSquirt. edit: You definitely have something wrong. Edited February 27, 2011 by CamH Quote Link to comment Share on other sites More sharing options...
pdkoch Posted February 28, 2011 Author Share Posted February 28, 2011 thanks guys, they are 325cc injectors which is bigger then stock so this makes no sense. im really thinking its my settings in megatune, could yall tell me how it should be set up. for the injectors im also running a resistor pack instead of the PWM. I think im going to go 550cc injectors next now anyways so i can go ahead and eliminate that when i change them. Thanks Quote Link to comment Share on other sites More sharing options...
CamH Posted March 1, 2011 Share Posted March 1, 2011 Go check out some of the tunes under the MegaSquirt forum and see if someone else's injector settings work for you. Quote Link to comment Share on other sites More sharing options...
dexter72 Posted March 2, 2011 Share Posted March 2, 2011 Your bigger injectors are low impedence injectors right?. Quote Link to comment Share on other sites More sharing options...
mobythevan Posted March 2, 2011 Share Posted March 2, 2011 Out of curiosity, what is megasquirt showing for injector duty cycle if you log it? If your required fuel settings are reasonably close for the injector size you are running then the duty cycle should be reasonably accurate. If it shows above 85% under load then it is another feedback that your injectors are too small. Quote Link to comment Share on other sites More sharing options...
pdkoch Posted March 3, 2011 Author Share Posted March 3, 2011 The injectors where supposed to be rebuilt stock injectors upgraded from stock 285 to 325cc The duty cycle will go over 200 on certain parts of the table even during autotune. ...but does that mean from stock ecu->megasquirt injectors need to be replaced too or? im going to get these: http://cgi.ebay.com/ebaymotors/Nissan-280Z-300ZX-Siemens-575cc-Fuel-Injectors-NEW-/350339827062?pt=Race_Car_Parts&hash=item5191e18576#ht_1067wt_939 Quote Link to comment Share on other sites More sharing options...
Leon Posted March 3, 2011 Share Posted March 3, 2011 The duty cycle will go over 200 on certain parts of the table even during autotune. You just broke physics! Quote Link to comment Share on other sites More sharing options...
CamH Posted March 7, 2011 Share Posted March 7, 2011 You should figure out what you have wrong first. Throwing bigger injectors on it right now aren't going to help you. Quote Link to comment Share on other sites More sharing options...
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