hey guys went to the dyno day today with a chipped Ecu with fuel map changed and rev limiter extended first two runs were very lean up in the 14's the hole time i was told it needs to stay below 14 i then changed it back to the stock ecu and it was still running lean not as much but still way to much any one can help would be great fuel pump maybe??? o2 sensors are still only 6 months old?? 5sp man N/A Podfilter cheers simon
Yeah, fuel pressure. Either fuel pump, or fuel filter. Mine was between 14.5 at the start to 12.5 high in the rev range.
chrispy any way of testing or should i just replace and go for another dyno and elimate the hard way the guys there said i should get an aftermarket ECU $$$ to correct it but if not working properly with stock ECU something must be wrong.. Hey chrispy what mods do u have to get to 135kw??
You need to test the base fuel pressure with an inline fuel pressure gauge, if the shop you were at had half a clue they should of been able to do this for you. There is no use replacing the fuel pump until it has been determined bad...
Engine tuners are always keen to sell you a new ecu, funny thing that The ecu thinks that everything works correctly, so you have to make sure everything works correctly! Easy As 300ZXT said ahve your fuel pressure tested. If it is down change the filter, if it's still bad check your fuel pump (I'll have a good NA one for sale soon ) If the fuel pressure is OK then it is probably your injectors, have them removed and cleaned. That should fix it. As for my mods... There all in my garage <<<<<<<<< Quick rundown: Apexi cat back "High flow" cats Unorthodox racing UDP Thermofan instead of clutch fan 1 piece driveshaft Apexi pod JUN adjustable exhaust cam gears My new ECU is still sitting on my coffee table Next weekend I promise...
thanks chrispy nice zed byy the way saw it today watched them do your timing good mate too he didn't smoke the tryes to much hahahaha kiddin cheers simon
Pity about the somewhat damaged rear bar though (stupid trucks ) And the whole car needs a good polish, and a gonzo nose
not that lean dude mid 14's is not lean for a n/a, i think you have been hanging with too many TT boys
err err id say your wrong. optimum fuel burning takes place at lambda 1 or 14.7 on the AFR scale, actually closer to 15 for unleaded fuel. it is perfectly acceptable to run a n/a car at lambda 1 or even 1.1 which is high 15 afr. that is a lean, hot mixture which is great for economy and mixtures. it is true that more torque is produced by tuning to lambda 0.9 whis is 13. something afr. this is a rich mixture so it is not optimum as you say. getting into 12 to 1 AFR for n/a is pointless
.... what is the point of NOT tuning for torque ? I don't talk about optimum burning rates for fuel, i talk about optimum power production.
use the right words then. 14 afr is not "lean" 12 - 13 is not optimum, that is rich. and even tuning for torque going below 13 is pointless
ok, let's say you run 14.x AFR how much timing do you think you can add before you ping compared to 12.7-13.x ?
optimum afr for NA is 12.5 - 13 afr at full throttle, high revs. Have been told this many times, and any sensible tuner will aim for these figures when tuning an NA. At cruise or light throttle conditions, the afr should be around 14.7, as that is closed loop running. Cheers
To be fair to this workshop, we were there for a dyno day, with 22 cars to be run in a fixed time period. There was not time for diagnosis and tuning etc. The dyno day for simon has performed it's task of providing him information about how certain aspects of his car are behaving at WOT. "IF" simon want's to do things to alleviate this "lean" condition, he can now take measures suggested. It's all about education, now you can see the graph Simon, you have a start point. Karl will know more of the Stock NA tune than most, and he will correct me if I am wrong on the following point The stock ECU will be aiming probably in the 12s somewhere for an AFR in the top end of the rev range. If you are not achieving that, then there will likely be a fuel delivery problem of some sort. I'm not interested in getting into discussion over what is the most efficient AFR, all I am saying is that on a Stock ECU, you are not achieveng the AFR the ECU is designed to deliver.
dyno graph.. all good points guys but to show you my graph i start off on 14.5 and pretty hold that line till detination.. [/URL][/IMG]
yes I would say that an afr of 14 is too lean, especially at high revs. Ideally it should be around 12.5 - 13, for both performance gain and safety... get your fuel pressure checked, and ensure that your fuel pump is working correctly. Also check your fuel pressure regulator and make sure that is running... There are a lot of things I can suggest to you, but its hard to describe over the internet, especially if you're not sure what I'm talking about... my advice would be to tee up with a zed expert forum member in your state, and they will be able to help. Cheers
