Intermittent leaning out

Wabbitkilla · November 7, 2007, 07:38

Right,

On the whole i'm a happy bunny (killer s:wink: :wink: s:wink: )

But i'm having an intermittent problem which shows itself as a stumbling or hunting tick-over on occasion while i'm out and about. If you're just doodling along in traffic it can seem a little hesitant too.

When I stop and allow the engine to idle the afr (innovate) swings around to the 18s and wobbles around a bit. Sometimes it'll eventually settle back to the 14.7 area, other tiimes I blip the throttle a couple of times till it settles. It nef=ver throws a cel relating to fueling, ignition or anything!

I've read that this can happen sometimes with e-manage, so it might just be one of those 'features'.

So i'm going to;
1. Reset the ecu.
2. Clean the maf (& reset the ecu)
3. Check with my new obdii reader to see if the O2's in the manifold are wandering (is this the cause or a symptom?)

Do you think i'm looking in the right places?

SteveJ · November 7, 2007, 08:22

Using the obd-ii reader, you will probably see that the car is in open-loop at idle - the O2's are not being used to control fueling - only the MAF.

Running lean at idle isnt a major problem.

Sounds like you may have a sticky IAC valve - a reset of the ECU should cause it to relearn how the valve behaves but will leave you with a high idle speed for a while whilst it does it.

Wabbitkilla · November 7, 2007, 09:58

IAC - now there's a good point!

I guess i'll take the intake off and try and get some carb cleaner in there too. May as well blast it all while it's on the ramps for oil change.

cclarke99 · November 7, 2007, 22:51

I'd certainly agree that a sticky IAC is a good place to start, but I thought the engine operates in closed loop mode at idle if it is warmed up. Without it, you might fail the MOT because if it is lean at idle it will give a high CO output. If you're looking at the ODB, it might be worth checking the coolant temperature is high enough. It might be high enough so that the idle up is inactive, but too low for closed loop control.

Tem · November 8, 2007, 04:53

Quote from: "Wabbitkilla"e-manage

I'd start by taking that off. If the stock ECU makes everything ok, you know it's the e-manage/tune.

spit · November 8, 2007, 08:18

+1. Periods of lean idle seems to be one of those things with EM. Perhaps this is why it features an anti-stall option? You could try shoving some small +ve values in the UL corner of the airflow map to coax more fuel through, but its more of an art than a science s:wink: :wink: s:wink:

Is idle an area you can set to learn from target AFRs on the EM-U?

Wabbitkilla · November 8, 2007, 09:27

You can set ANY area for the EMU to learn from AFR's s:wink: :wink: s:wink:

However this being of an intermittent nature, that seems like a sledgehammer to crack a nut. I don't think it's really much to do with the EMU, but more likely the IAC or a NB going adrift. Trouble is catching it in the act. All I can do is clean / squirt everything and make sure all is perfect and then troubleshoot with the OBDII.

spit · November 8, 2007, 09:51

Thinking out loud then ... in which case I'd suggest a MAF clean for starters. If its under-reading idle airflow the ECU will start to withdraw fuel. You'll go lean, the engine will stumble, airflow will continue to drop (and be mis-read), and you'll spiral in that lean state until you blip the throttle.

Wabbitkilla · November 8, 2007, 10:03

Excellent - sounds like a job for saturday s:wink: :wink: s:wink:

Sounds more likely that and/or the IAC as it occurs while driving too, but only when pootling rather than accelerating.

SteveJ · November 8, 2007, 12:36

Quote from: "Wabbitkilla"Excellent - sounds like a job for saturday s:wink: :wink: s:wink:

Sounds more likely that and/or the IAC as it occurs while driving too, but only when pootling rather than accelerating.

Does it feel as though the engine has stopped when on partial-throttle over-run - that seems to be a common thing with the eManage especially when larger injectors are in use, as it tries to subtract air in order to reduce the fueling, to the point that the ECU no longer registers air flowing over the MAF so it shuts the fuel off

As Ste suggests, it may be worth adding fuel in the map in the top left corner to counteract this.

Wabbitkilla · November 8, 2007, 12:49

Ah no - that's normal behaviour for the standard ECU.
But thinking out loud, it's similar - however THAT particular behaviour is normally remedied by a single push on the throttle.

VVT-i · August 4, 2008, 19:19

Hmmm.. I am now getting this problem, I'm getting a CEL on Idle (I can't remember the code now s:(

s:( ) and the WBO2 (Innovate) starts going to 16 - 18's, I also noticed that Idle was lumpy so I had a look in the engine bay... congratulations to me!! I spotted and (I think) fixed my 1st vacuum leak.. a small hose had come off so I reconnected it and Idle sounds a lot better, I reset the ECU but the AFR still goes to the 16 - 18's and the CEL comes back, but if I blip the throttle slightly it goes back to the 14.7(ish)

I read on the instruction manual for the Innovate that after 3 months you should re-calibrate it.. will this help if I done it? reading the instructions it seems quite a straight forward job.. even for an inadequate monkey like me s:(

s:(

The AFR readings are fine during normal driving and boosting.. it only happens at Idle, this is kind of pointing me towards what I've read here and to what spit told me last week, it could be the EMU idle control settings thingy. This is something I don't want to mess around with myself as knowing my luck I will delete the entire map lol. so if that's the way to go I will be booking the car in somewhere to get someone who knows what they are doing to do it. Also, reading on here about the IAC valve (Idle Air Control Valve I assume?) could it be possible that it's sticking on mine as I had lost 2 litres of oil on the 250 mile drive to the camping trip? if so, where is it and how do I clean it?

My thinking is this...

Reset ECU (done.. cel etc came back)
Check for vacuum leak (done, fixed, cel came back) will check for more loose connections though s;)

s;)
Reset the Innovate
Clean MAF
Clean IAC
Get the EMU Idle thingy set

Would the above be the correct order in which to do things.. or is there any other things I can do?

Oh!.. I don't think I've ever used so many EMU's, IAC's and CEL's etc in one post s:lol: :lol: s:lol: I must be learning something.

spit · August 4, 2008, 19:45

Davy - after my experience from the weekend, it may be worth cleaning out the IAC. A bit of a pain as you have to clamp a couple of water hoses off to remove the throttle body ... but it makes a helluva difference having a working IAC s:wink: :wink: s:wink:

I doubt your innovate has drifted too much if its reading sensible stuff under boost, so picking up from your sequence of stuff to do, I'd be inclined to do what you're planning and go with the cleaning regime before hitting the EManage.

Anti-stall on the EM is a comparatively clumsy 'fix', and it may not solve an issue that is lurking elsewhere, so save that as a last resort s:wink: :wink: s:wink:

evileye_wrx · August 4, 2008, 20:25

I fixed my idling/ stalling problem accidentally when I noticed one of the wires into the Emanage wasn't connected properly. Pushed it back in and no more problems since.

Phil

enid_b · August 4, 2008, 22:20

i was gonna say "then dont have your windows open when cornering at speed." but then i read on a little bit s:(

s:(

J

VVT-i · August 4, 2008, 22:40

As I am completely inept and keep loosing/dropping bolts etc is it OK to use something like this...

m http://cgi.ebay.co.uk/BG-406-Profession ... 0063760631 m

... if so, I take it I squirt it into my Induction kit AFTER the MAF? and how much would I need to use and would it reach the IAC valve if I do it this way or would I need to take off one of the throttle body pipes?.

What do I use to clean the MAF as this stuff says to use after the MAF?