AnWaRi996

I retried the glove thing with a slight variation and noticed that even with the car off (which should be zero signal), small amounts of air are exiting the IAC valve, which explains the fact that nothing is seen when the blade and IAC hole are covered together, but if the IAC is watched only, small amounts of air are leaking out. I don't really understand how this ties in with it all when the car is running though, as the valve should be open shouldn't it?

Yeah I noticed that. I taped a glove onto the end of the TB and forced air into a vac line but when i stopped the air didn't go anywhere, it acted like a perfectly sealed system. Is there a chance the idle valve is still functioning electronically but mechanically is actually in a different place than what the ECU sees it in?

Attached is a log of me covering the TB with a piece of cardboard at various intervals. At no point did the car die though. Feels like it definitely should've with most of (if not all of) the throttle body covered...? Thanks for your help so far! (edit: the cardboard was being sucked really hard despite the fact you said the idle valve was already closed?) no die.llg

Idling around 1500rpm now, still blowing a grey-ish smoke which I'm assuming is from burnt oil due to the rebuild - something about rings and seals settling in... What can we make of this? 1500rpm.llg

Testing it found a vac leak which when plugged up dropped the idle to around 2000 (with the idle valve connected), although target is set to 1500ish I think, smoking up a fair bit too. No more vac leaks anywhere. Can't help but feel like a valve issue at this point, as the ECU isn't really seeing anything and it's just overshooting targets, blowing smoke, and no vacuum leaks. That said, It's a fresh rebuild so I don't think a leak-down or a compression test will show anything so it might just be heads off and have a look? I don't know where else air could be coming in from.

The stop is already all the way out it looks like, so I guess we're potentially looking for another vac leak? Initially i thought my PCV could be stuck open but I'm running speed density so it would be giving me air into the intake before the sensor anyway? Really at a loss.

Attached the tune and another log without the IACV plugged in. It is the later 3 wire solenoid type. Unplugged, the idle dropped the a steady 2000ish and there was less of a fuel smell/smoke. I've also checked for resistance across all pins and there's no register of anything between any of them although I'm told there should be some sort of resistance between pins. Sounds like the valve is dead? WRX tune.pclr more logs.llg

It's a 2003 EJ207 tuned for on a WRXlink 5+. The idle valve has been replaced during a rebuild but not with a factory one, and since the rebuild it's been acting funny, so I haven't actually narrowed it down to that. I've checked near everything for leaks around the engine and can't find anything at all. The blade seems to be perfectly fine upon checking it. Is it just a matter of unplugging the IACV and seeing what happens differently? I'm of the belief these IACVs from this engine aren't adjustable anyway (correct me if I'm wrong) so it would entirely be faulty from the go? Is there an easier way to test the valve through Link software? Sorry about the barrage of questions, really at my wits end with this and just want to drive it at this point.

Hey guys, just trying to diagnose this extremely quick idle ramp up from start, basically shoots straight to 3k RPM instantly and hovers around there. Injectors, spark, and air are all good, which led me to believe it was an o2 sensor issue. When checking the log (which I've attached), everything seemed normal barring the mixture map, which is throwing errors saying that it's expecting .95v and is getting 0.00v from 200 odd samples. Does this indicate an issue with the sensor or even the sensor wiring? It's just a stock narrowband but I'm fairly certain it's meant to fluctuate? I also don't understand how to read the fuel table but when i click on one of the red mixture map squares, it highlights the 2500-3000RPM area, which is exactly where my idle is going to and is what's giving me this feeling. Attached are images of what I'm referring to alongside the log. Thanks in advance. potential issue.llg

Yep, injectors are clicking, all in order. It is a V8 engine and it was previously running on a trusted tune. If nothing is obviously wrong then I'm assuming it's a timing issue that will need to be traced back through possible wiring issues, maybe spark wiring is a bit muddled? Fuel is definitely happening, so is air, and it's a brand new timing belt perfectly lined up.

Hey guys, running a wrxlink 5+ and although my car was previously running (albeit horribly), after repairing the loom it wont start. not really sure of the cause so wondering if something is visible. Attached is the log and triggerscope. Thanks Log 2021-05-27 4;10;42 pm.llg Trigger Scope Log 2021-05-27 4;15;00 pm.llg

That's what I was leaning towards, are we able to take an educated guess on whether its the intake or exhaust side of the engine due to the symptoms? or just an air leak anywhere post IAT and pre O2? I have a feeling it's bent valves but a compression test later in the week will determine that.

The car has already been tuned and was running great beforehand

Yeah I'm just running the stock O2 right now. Later down the track I will, but surely it should show something irregular at the moment.

Hey all, I'm having trouble diagnosing a horrendous running car. As soon as it starts up idle ramps up to 1600 and it blows obscene amounts of black smoke. The plugs are sooty and it's misfiring but I'm not sure what I'm meant to be looking for in the logs (which are attached) I've noticed the O2 sensor on AN Volt 4 doesn't ever show a reading other than 0.0v although my understanding is that it should cycle between 0.0 and 0.7, which would mean that the car is only seeing a lean mixture. Could this then be a result of a faulty o2? Otherwise i'm not really sure how to interpret the log to diagnose the current issue. Really just unsure of what the ecu is seeing that is causing it to act this way and any insight would be amazing! 602985825_richrunandmisfire.llg