Rolls

I have had weird idle issues before with my idle going as lean as 17-18:1 when hot, but then dropping back down to 14:1 randomly. The fact that the O2 sensor says it is lean at cold start idle vs rich when warm could be evidence of that, wish I knew someone with a wideband as it is a pain in the ass to drop it somewhere just to check the cold idle. How reliable is the rich/lean condition of the O2 sensor, should it be lean at idle? You'd think when cold it would want a rich idle to be stable.

Ok today the idle was great again, started first go, no pops then after about 10 seconds would get an ever so slightly mild pop, idled great the entire way to work. log says ~1100rpm+-20rpm so stable, water temp was about 20c, tps 0.88, 30 degrees timing, 2.08-2.11ms injector, O2 still reading lean. After about a minute idle dropped to ~900 and timing dropped down 1 degree at a time to 26 degrees eventually to 15 degrees when warm. The only difference between today and yesterday is it is much colder this morning and I left the car outside, the other thing is I drove straight home without really getting over 60 last night. It is possible the plugs are just fouling up on boost maybe? Can try playing with the TPS but I think it is something else, it just doesn't make a whole lot of sense to go from almost undriveable to perfect over night and then back again.

We adjusted the trigger voltage to 1.0v I believe, you can confirm by the "closed throttle" being at 1 and when I touch the throttle and it goes above 1v it goes to 0 When we adjusted the trigger voltage below this it would just rev and hunt weirdly, I am positive it is in the idle mode when the throttle is closed as it isn't doing this.

here is the log ecutalk1362012_2.xlsx

When it has been running for a few minutes the timing drops back to 20 then 15 degrees at idle TPS is at 0.88v when idling, I can try adjusting this, is there a screw on the tps itself?

Did you turn O2 feedback off and lean it out at cruise? If you did that I could believe it, but with stock O2 feedback unless it is entirely highway kms with basically no boost Im sceptical.

Ok did a log when cold, when at 1200rpm the duty cycle is 1-2 and pulse width is 2.2ms, when it stumbles duty is 1 and pulse width grows to 2.5ms all the way to 3ms when it starts missing badly, timing changes from 30 to 34 when stumbling, acc duty increases slightly. Stab the throttle and it goes back to 1200 and duty at 2, pulse at 2.2ms, starts to stumble and go up to 2.8ms etc. Would this be as simple as just changing the cold start enrichment at 20-30c so it is slightly less rich? I'm going to buy a license next month so will have a fiddle then. So I am guessing the cold start is just simply too rich

no you don't

Hmm this morning it was much much better, I didn't drive the car yesterday at all so it must have been completely stone cold, still did a slight miss for 3 seconds then come good for 3 seconds but it didn't want to stall, just went from 1300rpm to 1000-1100rpm. Tonight it was back shit again wanting to stall from 1300 to 400rpm. I have my laptop back so I will plug in consult and do a dump of injectors/afm etc vs rpm when its cold see if it is an ECU or mechanical problem, I personally think it is fouling the plugs up from possibly too rich an idle.

Be interesting to see what kind of real world differences they get in terms of power and fuel usage at low loads.

whats happening in the sphincter of the universe ?

I work best at night, often write software when I am pissed that I wouldn't normally be motivated to do, then I get kudos from my boss and some extra money.

right back at you im a night owl, I went out tonight, then I came home, sobered up, and did a few hours of work as Im not tired for some odd reason, it is a public holiday tomorrow and I have zero things to do.

Seems like a misfire when cold, cannot figure out why though, really need to get a wideband in the exhaust to see if it is going lean/rich or if it is super rich at idle fouling the plugs. Bummer because I have neither a wideband, nor a nistune license.

Fuel pump is new and rewired to battery voltage, O2 feedback is enabled as well, just need to borrow a laptop so I can run consult again. Does anyone know what the "Fuel Dumper" is? as I did not get this part when I bought my fuel rail, is it a dampener of some sort? Perhaps this could be my issue.

Definitely a possibility, if I was to pull the plugs after a failed idle when I start it how could I tell if they are fouled easily? Actually the only times the car idled well was when we first put the injectors in, then it went to shit, and then I changed the plugs before the tune and it was shit after that, then came good for a week then went shit again. Maybe they have just fouled up badly.

Just got my policy renewed with just car 25 year old, car stolen about 6 years ago, no claims, no DUI etc, plenty of tickets R32 skyline with rb25 swap, rims, alarm, injectors, turbo $660 a year paid $55 per month $1.5k excess Agreed value: $12k

Why would you even bother taking it through if it had that much stuff obviously wrong with it?

Yeah I'll multi meter it all up. I just get the feeling it is something else as it did idle perfectly for a week twice, this hasn't been connected ever.

I meant I made 20kw extra due to the better flowing head in the neo, my turbo was right on the limit and out of flow but by removing a restriction in the head (33 to neo) I was able to make more power, if you aren't flow maxing your turbo it won't make much difference htough. Pistons usually break due to detonation, if you have a det free tune they will handle 400rwkw.

they also have a much better flowing head, basically the same as rb26 head just with shim over bucket instead of shim under bucket which can cause issues if they spit one out, pretty unlucky for that to happen though. Mine made an extra 20kw when going from an r33 motor to neo, 230 - 250kw with the same turbo.

neo is hands down a better motor, everything about it is better, plus it is newer, I wouldn't ever consider a 33 one. like what? everything from r33 is bolt on, you can even bolt the entire r33 intake onto a neo motor if you want.

Lucky you noticed it early, could have been much worse.

AWD will load the car up differently than RWD as well, probably not enough that it would effect the tune but it is plausible.

Ok made absolutely no difference with it plugged in or not, I tried unplugging the TPS, AAC, O2 sensor and none of them effected the idle at all. I held the revs at 1500 and it started to hunt between 900 then back up to 1500 then back down and pop and fart, got a lot better after a few minutes and when warm it went away, this says to me it isn't an idle problem, I can even feel it missing when cruising at 60 in 5th then come good then miss again, goes away when warm. I am starting to think I have a misfire or an injector not firing properly when cold, unsure how to diagnose this further though? I will put the consult cable back in and check the timing isn't shifting due to say a stuffed CAS or something as well. edit: Brand new plugs as of 500km ago 0.8mm gap with 6 heat range.