moosetrain Posted July 10, 2022 Report Share Posted July 10, 2022 Hi guys, Got a 300zx running link with nismo 740cc. Got it idling at near 14.7 However I had to use master fuel at 25ms, is this value too high? I am not sure if there is another issue present as others seem to have a much lower master fuel. I've attached the map and a log. Cheers. fuel25.llgx 300zx.pclx Quote Link to comment Share on other sites More sharing options...
remski2 Posted July 10, 2022 Report Share Posted July 10, 2022 For starters.... You need to fix your IAT. Its adding 4%. Also you should wait until all your trims are done, then tune the AFR.. Your log still shows Warm up enrichment active. Quote Link to comment Share on other sites More sharing options...
essb00 Posted July 10, 2022 Report Share Posted July 10, 2022 Your MAF is not reading correctly. Check the connections/wirings. What's your reference for having 14.7 AFR? You do not even have any lambda sensor selected in your tune file - only NB o2 sensors (as GP analog) which also are not having any calibration table set. Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 11, 2022 Report Share Posted July 11, 2022 Yeah 25ms master is unusually high for 750cc injectors based on the rest of your set up. I would generally expect it to need about half that. So it suggests you are getting much less than 750cc of flow - either the injectors are smaller than you believe or something like the fuel pressure is very low. 5 hours ago, essb00 said: Your MAF is not reading correctly. Check the connections/wirings. Maf is not being used in the fuel calc. Quote Link to comment Share on other sites More sharing options...
moosetrain Posted September 19, 2022 Author Report Share Posted September 19, 2022 Hi guys small update on this one. Got all my parameters wired in IAT, fuel pressure temp etc. I have it idling at 14.7 AFR at full temperature. My final master fuel ended up being 38ms.. My fuel pressure was perfect for the entire time @43psi . Thinking I got sold dodge injectors. Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 20, 2022 Report Share Posted September 20, 2022 Yeah that seems very odd. Whats the effective PW showing at idle? Quote Link to comment Share on other sites More sharing options...
moosetrain Posted January 7, 2023 Author Report Share Posted January 7, 2023 @Adamw it was about 3ms at 14.7 afr. Quote Link to comment Share on other sites More sharing options...
Adamw Posted January 7, 2023 Report Share Posted January 7, 2023 Can you attach your tune and a log of it idling. Your idle PW is longer than it should be but I dont think it is wrong enough to need the master at 48ms, so I suspect you probably have multiple issues. Quote Link to comment Share on other sites More sharing options...
moosetrain Posted September 12, 2023 Author Report Share Posted September 12, 2023 Wow time flies. @Adamw See attached logs of car idling + map. 33ms master is what the final number ended up being. I have affirmed fuel pressure, and smoke tested the system. These injectors may potentially NA injectors from this master ms value. idlewithblip.llgx basemap12_9.pclx idlinglog.llgx Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 12, 2023 Report Share Posted September 12, 2023 I would say your injectors are <300cc/min based on those logs. Quote Link to comment Share on other sites More sharing options...
moosetrain Posted September 13, 2023 Author Report Share Posted September 13, 2023 Thanks @Adamw, out of interest how did you determine this? Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 13, 2023 Report Share Posted September 13, 2023 I plucked some numbers out of your log and put them into a spreadsheet I occasionally use to validate fundamentals. The bit down the bottom uses PV=nRT to approximate air and fuel mass flow from VE. So assuming a typical VE of about 60% at your small throttle opening, I had to input an injector flow rate of 245cc/min to get a similar PW to what your log shows at the same RPM/MAP/Temp. castillaricardo and moosetrain 2 Quote Link to comment Share on other sites More sharing options...
DerekAE86 Posted September 15, 2023 Report Share Posted September 15, 2023 On 9/13/2023 at 11:01 PM, Adamw said: I plucked some numbers out of your log and put them into a spreadsheet I occasionally use to validate fundamentals. Would it be possible to get a copy of this spreadsheet? I'd love to fiddle to get a better understanding of how the VE fuel equation spits out the final ms value. Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 18, 2023 Report Share Posted September 18, 2023 Excel file attached. Note it is simplified compared to the ecu, it doesnt consider fuel temp or the charge cooling effects of the fuel, fuel press etc, but it will give pretty similar values in most cases. Injection Calcs.xlsx DerekAE86, Confused, castillaricardo and 2 others 5 Quote Link to comment Share on other sites More sharing options...
moosetrain Posted September 23, 2023 Author Report Share Posted September 23, 2023 On 9/18/2023 at 10:02 AM, Adamw said: Excel file attached. Note it is simplified compared to the ecu, it doesnt consider fuel temp or the charge cooling effects of the fuel, fuel press etc, but it will give pretty similar values in most cases. Injection Calcs.xlsx 14.51 kB · 10 downloads Replaced the injectors with some brand new Deatsch Werks 740cc injectors. Car idles at ~ 1 lamba at 17ish ms master fuel, which seems still wrong. From what I work out the number should be closer to 7ms. Using this file (plus the tune and log attached), I've come to see the injectors are 370cc ish. Struggling to think what else is the problem. I updated the dead time with the supplied values, is there something else I am missing here? lognewinjectors.llgx newtune740cc.pclx Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.