98cobra+75280z Posted November 21, 2011 Share Posted November 21, 2011 So i have gotten my car to idle and drive resonably well. There, however, seems to be a couple things that i can t smooth out. Ill start by a describing my car '75 280z -'82 l28et -MS1 v2.2 with a GM HEI-4 module -Walbro 255lph pump -stock (260cc) injectors -stock FPR -FMIC with BOV -slightly larger (water cooled) turbo Issue 1. The car idles way to rich, i mean like afr's of ~10.5 to 11.2. what should these l28et's idle at? I cant seem to correct this and retain a good idle quality. I played with the fuel REQ and took it down and that raised my ARR's but once they hit like 12.5 or so i got some lean pops in my exhaust. This makes me worry that the car will lean out when i drive and get under some boost. I then tryed to lower the fuel in my VE tables, which kind of worked but not really. Is there any other options.? Issue 2. The AFR's swing back and forth from 11.2 to 16.0 when im cruising under a light load. this happens all the time when cruising even though ive been using autotune in megatune to try and get my VE table closer to match my desired AFR's. What can i do to get this to smooth out?? One additional question, I have a manual boost controller so im wondering how much boost can i push with stock injectors? this is of course only going to happen once i get these other issues handles. thanks guys.! Quote Link to comment Share on other sites More sharing options...
letitsnow Posted November 21, 2011 Share Posted November 21, 2011 Is EGO correction turned off? It should be while tuning. Is your VE table smooth around the cruise area? You may have to adjust timing to get it to idle leaner, I've got mine to idle pretty well at 14ish. Quote Link to comment Share on other sites More sharing options...
Leon Posted November 21, 2011 Share Posted November 21, 2011 The leaner you want it to idle, the more you must advance timing. Mixture burn duration increases as the mixture leans out. Quote Link to comment Share on other sites More sharing options...
98cobra+75280z Posted November 21, 2011 Author Share Posted November 21, 2011 Is EGO correction turned off? It should be while tuning. Is your VE table smooth around the cruise area? You may have to adjust timing to get it to idle leaner, I've got mine to idle pretty well at 14ish. What is your timing around 800 to 900 rpm, mine is set to be 20* BTDC. should i advance my timeing or retard it further? I wont be able to tune again until Wednesday so ill take a look to see if my EGO correction is off or not, Thanks for the heads up. My VE table is the same one from the FAQ section for the stock l28et, it seems smooth to me but i can post it later if you guys want to take a look at it. I can say there are no sudden jumps in it. Quote Link to comment Share on other sites More sharing options...
98cobra+75280z Posted November 21, 2011 Author Share Posted November 21, 2011 The leaner you want it to idle, the more you must advance timing. Mixture burn duration increases as the mixture leans out. What would you suggest i advance my timing to , just looking for a ball park area, right now at 800 rpm it is around 20* or so Quote Link to comment Share on other sites More sharing options...
Leon Posted November 21, 2011 Share Posted November 21, 2011 What would you suggest i advance my timing to , just looking for a ball park area, right now at 800 rpm it is around 20* or so I would do a timing sweep, from 10-20deg BTDC for example. Lean the mixture and find where it's happy at in terms of spark advance. There is no number set in stone, each engine is different. Quote Link to comment Share on other sites More sharing options...
letitsnow Posted November 21, 2011 Share Posted November 21, 2011 Mine seems to like 25 degrees at idle. Quote Link to comment Share on other sites More sharing options...
98cobra+75280z Posted November 22, 2011 Author Share Posted November 22, 2011 Mine seems to like 25 degrees at idle. what are your AFRs at idle? Quote Link to comment Share on other sites More sharing options...
letitsnow Posted November 22, 2011 Share Posted November 22, 2011 14ish, they've been a little erratic lately, but I'm nearly positive that I have an injector or two that's partially plugged. Quote Link to comment Share on other sites More sharing options...
FricFrac Posted November 22, 2011 Share Posted November 22, 2011 Mine didn't follow the AFR until I turned the EGO Sensor Type to Wideband - opps I also noticed my AFR reading in TS is about .5 off from the gauge..... and I also forgot about the bright blue lettering below the setting for the EGO that says "Remember to Calibrate and set Project Properties"..... doh! Calibrate sensor helps as well.... Quote Link to comment Share on other sites More sharing options...
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