Ok, so I got the silver bullet working on 6 cyls after the really really really overfueling thread. Took it to be dialled in correctly on the dyno on sat. Having some kind of issue with idle stability due to inconsistant afr's. Being that I had these injectors installed on the red zed and running well, I had a decent starting point with kval and latency. Idle afr's are fluctuating from really rich (10:1) to really lean. When idle stabilizes afr's are 'normal' (likewise when idle afr's stay steady idle is smooth). Then with any throttle input afr's go instantly rich (10:1). Give it more throttle and afr's normalise again. At cruise loads, afr's seem ok, again until any slight throtte input, then afr's go really rich again, and if I increase throttle afr's normalise again. The only changes to the car have been the injector (and connector swap) and also gone from single afm to selin and twin afm. AFM voltages are expected values using both single and the selin setups (in both AVE OR ADD modes). I did a BLT after the first plenum pull and it was good. Haven't done another since the last plenum pull, however I am not expecting any vac leaks (but I will have to confirm). Issue seems to very intermittant, as on the dyno, the tuner was able to do a run, come down to ide and idle fine, make changes to map (still idle fine), do another run and come back to idle and then it would idle like balls. I am thinking it is wiring related, possibly an injector (or 2 or 3???) is earthing out when it shouldn't. Maybe I am overlooking something stupid? School me on what contributes to idle injection and light load richness please. Any other things to check or ideas appriciated. Mike :zlove:
Only 1 x o2 strangely enough. The plug for the passanger side has be zip tied together so it can't be connected, I assumed for a reason. Very small about of the map has o2 feedback active. (about 8 cells) Could this be contributing?
I found O2's gave me some funny results. I unplugged them and everything worked a bit better. Could have just been my dodgy tune though
I had a similar problem with my AFRs according to Dave at UAS (back when he was working there) and he blamed it on the twin intakes slowing the intake air and making the maf sensitive to gusts of wind. That was his theory anyway. It improved a lot with switching the Selin to average instead of add (and making the corresponding change in nistune). He also recommended I shield the intake pods better which I didn't do - idle is still a bit rough but doesn't worry me because still pulls like a freight train at (wot) which is my main concern.
Interesting, I'm having a similar idle problem and also have a Selin twin MAF converter. I also ignore it because it runs fine at load
Yeah I tried going back to the single t intake and it didnt change anything. Afm voltages were as expected, on single and dual with selin in add and ave.
My suggestions on how to fix this problem Clicky 1 Clicky 2 Clicky 3 And if Cara lets you have some more nickels Clicky 4
stock ecu? without 2 working 02 sensors you cannot set the idle map properly hence the hunting.. what injectors?
Nistune. Jecs 1000cc. Had them running fine in red zed so I had a very good starting kval and latency
That is all very interesting and all, and I won't rule it out. Having said that, when it was on the dyno I reverted back to a single stock intake to try and rule out the selin being an issue. Idle did not improve. However the plugs could have been fouled at the time causing incomplete burn and low afr's. I have purchased another AEM wideband, so when that arrives I will be able to compare bank to bank to try and isolate the issue.
