Running Rich on Idle - A/F learning -16%

[Booki]

Hey all,

 

Thought I would post my issue here, I struggling to find the issue.

 

I have a MY09 Forester XT.

 

I have had the engine out and recently put it back in with the list of the following parts;

 

Full list;

Brand new Shortblock from Subaru EJ257

Reconditioned Heads

VF52 Turbo

3 Port BCS Grimmspeed

3 inch Turbo back exhaust

TGV Delete

Air Pump Delete

PSR Silicone Turbo Inlet

Throttle Body Coolant Bypass

Dual Catch Cans

ARP Head Studs

FelPro Permaseal MLS head gasket

Standard Fuel Injectors/Fuel System/Pump

 

It recently only had a TBE, VF52 and 3 port prior to the new block/reco heads and other items. The car ran fine prior with the same tune. Idled fine and the AF learning was -3% give or take in all area's.

 

Now the car is back together, the idle is rubbish. It just doesn't sound right. I believe its running pig rich with -16% on idle.

 

But actually driving the car, it seems fine? Just the idle sucks and on od occasion it kind of "misses/hesitates" around the 2000-3000rpm range with light throttle.

 

So something up with the idle area of the car.

 

I believe its mechanical, but yet to find any mechanical issues. Have checked everywhere for vacuum leaks, sprayed soapy water around all connections and yet to find anything obvious.

 

Pulling my hair out here.

 

 

 

[MTBwrench]

Are you testing for vacuum leaks starting pre or post turbo?

I see you say standard fueling, were any of those components recently changed?

What tune do you have loaded, is it a custom tune and does it account for any changes?

Have you verified your MAF and/or O2 sensor are functioning properly?

Are you sure you have proper fuel pressure, and proper vaccum on the reg?

Are you sure it's not misfiring and dumping fuel out the heads, causing the fuel trims to go wonky?

 

Pulling that much fuel means you are probably right, it's running pig rich, but a lot of questions need to be answered still. Unfortunately, it's super hard to diagnose these things over the internet... I'd sort though all of the questions above and see where that gets you. I dealt with the exact opposite issue(running far too lean at certain RPM's) for the longest time, only to discover it was my fuel pump failing. It wouldn't flow much at all at certain duty cycles, but act fine for others.

[relative4]

It recently only had a TBE, VF52 and 3 port prior to the new block/reco heads and other items. The car ran fine prior with the same tune.

 

Confused... can you please clarify what has been changed since it was last tuned?

[Booki]

Are you testing for vacuum leaks starting pre or post turbo?

I see you say standard fueling, were any of those components recently changed?

What tune do you have loaded, is it a custom tune and does it account for any changes?

Have you verified your MAF and/or O2 sensor are functioning properly?

Are you sure you have proper fuel pressure, and proper vaccum on the reg?

Are you sure it's not misfiring and dumping fuel out the heads, causing the fuel trims to go wonky?

 

Pulling that much fuel means you are probably right, it's running pig rich, but a lot of questions need to be answered still. Unfortunately, it's super hard to diagnose these things over the internet... I'd sort though all of the questions above and see where that gets you. I dealt with the exact opposite issue(running far too lean at certain RPM's) for the longest time, only to discover it was my fuel pump failing. It wouldn't flow much at all at certain duty cycles, but act fine for others.

 

 

Thanks for the reply! Will try and answer these as best as I can.

 

 

I have tested for boost leaks pre turbo with a homemade boost leak tester - couldn't see anything obvious. That said I puton a boost map and it hit 18psi no issues at half throttle, so I don't think there is any boostleaks.

 

 

The fuel system is 100% standard, injectors, regulator and pump.

 

I have been working with my tuner and he has scaled the MAF to bring down the rich learning afr condition on idle. He said this was unusual for the mods that have been done to the car.

 

The MAF and O2 are functioning correctly to my knowledge, I swapped the MAF off another identical forester to see if it made any difference. The O2 sensor reads the same as my Wideband sensor.

 

Fuel pressure has been tested, approx 36psi on idle, goes up to 42psi from memory when I plug the vac line to the regulator.

 

I don't believe its missfiring, the idle is a little rough I would say but not as bad as say if I unplug a coilpack.

 

 

 

My current situation is now the MAF has been scaled, the trims are acceptable. But from what I have read from many others, TGV Deletes, air pump delete and a turbo inlet shouldn't make my car run rich on idle.

 

So its a bit of a mystery

[Booki]

Confused... can you please clarify what has been changed since it was last tuned?

 

 

The original tune was for a VF52, Turbo Back exhaust and a 3 Port.

 

Since then I have swapped in a EJ257 shortblock from subaru, removed the TGV's with KStech weldless delete kit, Airpump delete and added a Turbo Inlet, throttle body coolant delete, catch can and ARP headstuds.

 

Those mods to my knowledge should not have made the car run rich

[Booki]

So after all that trouble shooting (Boost leak tests, checking for vac/intake leaks, re plumbing my catch cans, spraying everything with soapy water, checking fuel pressure), I think it might just be the MAF needed to be scaled to suit. as I could not find any intake leaks at all.

 

This brings me to another issue with the car - Sometimes on startup, it smokes.

 

Not just a little, but in my opinion quite a lot.

 

At first I thought it was normal condensation type smoke, but it kind of lingers in the air. This has happened two or three times since the car has been on the road (about 7 days or so now).

 

It doesn't happen instantly after startup, but after say 20 seconds or so it will start to smoke.

 

See the vid, I only just managed to capture it on my phone, it was a bit worse then the video shows but calmed down when I started recording.

 

I am thinking maybe my turbo is on the way out? but at this stage I am only speculating. I am not sure how to diagnose a bad turbo just yet, but the rest of the engine is as new (brand new short block and reconditioned head from a machine shop)

 

Definitely open to opinions/theories from the more experienced Subaru owners out there

 

[solidxsnake]

What does it smell like? If it doesn't smell like oil or coolant, it's probably not a big deal.

 

FYI, my car has been doing this for the last couple of months that it was driven. Smokes at startup, smells like oil, but doesn't smoke after 10 sec or so. No smoke at WOT. I know I have a leak somewhere on the block, and I'm fairly certain the PCV valve needs replacement, but beyond that I'm not seeing absurd oil consumption or performance issues. If your smoke doesn't smell like oil/coolant and you're not seeing any consumption, it's probably nothing to worry about.

 

[ame=http://www.youtube.com/watch?v=hduvZ_BFdYc]SMOOOOKE - YouTube[/ame]

[relative4]

The original tune was for a VF52, Turbo Back exhaust and a 3 Port.

 

Since then I have swapped in a EJ257 shortblock from subaru, removed the TGV's with KStech weldless delete kit, Airpump delete and added a Turbo Inlet, throttle body coolant delete, catch can and ARP headstuds.

 

Those mods to my knowledge should not have made the car run rich

 

TGV delete, air pump delete, catch can... should not affect the tune.

Throttle body coolant delete... (shrug)

New engine. New engine? Really? Yes. The tune will need adjusting.

Apparently, the tune has now been adjusted, and you're now fine?

[relative4]

Sometimes on startup, it smokes.

How long after the engine rebuild did this start? What was done to the heads? What prompted the engine rebuild?

What is the history of the turbo? Have you checked the shaft for play?

[Booki]

TGV delete, air pump delete, catch can... should not affect the tune.

Throttle body coolant delete... (shrug)

New engine. New engine? Really? Yes. The tune will need adjusting.

Apparently, the tune has now been adjusted, and you're now fine?

 

 

Yes brand new Subaru EJ257 Shortblock. I figured the most streetable option (longevity, reliability important factors) was too just buy a brand new motor from subaru. It worked out cheaper then getting my existing shortblock rebuilt with forged internals.

 

All that seemed to be adjusted was the maf scaling. The car drives great bar a few niggling issues - the idle is kinda rough. Like it kind of shakes a tad. Its not as harsh as misfire but maybe a tiny miss every now and then on idle.

[Booki]

How long after the engine rebuild did this start? What was done to the heads? What prompted the engine rebuild?

What is the history of the turbo? Have you checked the shaft for play?

 

 

It smoked maybe after the second or third startup after the rebuild.

 

The Heads had been reconditioned by my local cylinder head shop - they got shaved flat, hottanked/cleaned and valves adjusted - I did check the valve lash after bolting the head on, some were not in spec according to my measurements (going off subaru FSM) but they assured me the specs/clearances are fine. Took there word for it, they have been doing it for 20 years as to myself who has been doing it for 20 days.

 

Reason for the build was due to loosing coolant. eventually traced it to contaminating my engine oil. Long story short I believe it was due to 10 seconds or so it ran hot (reason being from a airlock when installing the VF52). By the time I put in new internals, measured everything, got everything flat I just opted to buy a new shortblock.

 

The VF52 turbo I picked up used, unsure of km's, or condition. There was the normal amount of shaft play, did not see any damage on the sides/fins of the turbo so slapped it in. The car ran great, builds boost fine and seemed to run alright! The turbo had only been run in my car after the overheat (as thats when it was installed, and my "friend" i left with the car failed to tell me how much actual coolant came out during the turbo swap)

[Booki]

What does it smell like? If it doesn't smell like oil or coolant, it's probably not a big deal.

 

FYI, my car has been doing this for the last couple of months that it was driven. Smokes at startup, smells like oil, but doesn't smoke after 10 sec or so. No smoke at WOT. I know I have a leak somewhere on the block, and I'm fairly certain the PCV valve needs replacement, but beyond that I'm not seeing absurd oil consumption or performance issues. If your smoke doesn't smell like oil/coolant and you're not seeing any consumption, it's probably nothing to worry about.

 

 

Hmmm, it looks kinda similar smoke but not quite as dense and doesn't really have much of a odor. If anything it smells like regular exhaust.

 

The car didn't do it this morning though, so im not sure!

 

I have deleted my PCV valve, so thankfully don't have to worry about that!

[relative4]

You deleted your PCV valve? Please go on.

[Booki]

You deleted your PCV valve? Please go on.

 

What do you mean?

[relative4]

OK, I see you mean you replaced it with a catch can. Well, a catch can problem is also a possibility, but more likely the problem is with the engine itself. How many miles on the build? If it's very new, the rings could still be bedding, otherwise, well, bad build.

Or of course it could be the mystery turbo. Always a risky choice, that.

[xt2005bonbon]

Do you have the BtSsm app or use romraider to log? Have you been monitoring the 'roughness count' per cylinder at idle? Cause you've been mentioning a few times the car has been idling a bit rough..

[Booki]

Do you have the BtSsm app or use romraider to log? Have you been monitoring the 'roughness count' per cylinder at idle? Cause you've been mentioning a few times the car has been idling a bit rough..

 

I didn't know there was a way to monitor the roughness count per cylinder?

 

I had been "monitoring" the slightly rough idle by the super accurate bum dyno! I just don't remember the idle being not as smooth as before.

[Booki]

OK, I see you mean you replaced it with a catch can. Well, a catch can problem is also a possibility, but more likely the problem is with the engine itself. How many miles on the build? If it's very new, the rings could still be bedding, otherwise, well, bad build.

Or of course it could be the mystery turbo. Always a risky choice, that.

 

I am scared it might be a bad build from Subaru...the headache in returning it - I can only imagine.

 

It's done approximately 400km so far on the build.

[xt2005bonbon]

I didn't know there was a way to monitor the roughness count per cylinder?

 

I had been "monitoring" the slightly rough idle by the super accurate bum dyno! I just don't remember the idle being not as smooth as before.

 

With romraider or the btssm app, or even the accessport, you can monitor misfire per cylinder sometimes called 'roughness count' or something like that. I'd say log these. Hopefully, they stay at zero at all times. Occasionally, you may see a count of 1 or 2 and then it goes back to zero. If it is occasional (keyword here), then there should not be anything to worry about. But, if it keeps showing up and the number creeps up (particularly in a given cylinder), then you may have to do some troubleshooting.

 

When I got my heads refreshed (valve clearance reset) by some small shop, I then began to monitor these parameters and noticed that cylinder 2 kept showing a count of 1-12 at warm idle. And I recall the car shaking a bit at idle. People kept telling me that's normal Subaru behavior. Yeah right. Fast forward 10k later, I checked the clearance and they messed it up in that cylinder. After I fixed it, all good.

 

additional note: a misfire CEL shows up when the misfire count begins to pass a count of 30-35. Once, I had an injector that was not seated properly, the misfire count was going crazy looping between 1-99 .

[Booki]

I will definitely monitor this on my next drive.

 

I have similar symptoms to you, car has a small shake at idle sometimes. Not all the time, like it snot consistent just a bit of a rock say every 10 seconds or so? Havn't timed it to be honest.

 

I will be very annoyed at the shop if thats the case, as I did question them with the readings I got at home - and was told that the clearance's had been set and were set correctly

 

Unfortunate part is, it will be a engine out job to reset them IF thats the issue.

[xt2005bonbon]

Unfortunate part is, it will be a engine out job to reset them IF thats the issue.

 

Not necessarily. I've done it twice with the engine in place. You'll get a strong back for sure after that .

[Booki]

I wonder if the engine bay sizes are a bit more forgiving in the earlier series cars you have.

 

The 2009 Forester XT is pretty tight near the valve covers!

 

Even removing a valve cover with the engine in the car looks like a nightmare!

 

Fingers crossed its not that, but i am leaning towards it....I still have all the measurements recorded when I checked the valves after the shop had adjusted them.

 

Didn't drive the car today, hoping to take it for another drive tomorrow to see if the smoke is still there or not.

[Booki]

Started the car today.

 

No smoke on initial startup, but then started smoking about a minute after of run time.

 

Not alot of smoke, but enough to know something is not right.

 

When revving the car you can see some smoke coming out, as well as just holding it at a constant rpm (ie 2000rpm)

 

Something is not right I believe, either the heads or the bottom end.

 

The one time I choose not to build a motor - Buy a new block from subaru for convenience and get the heads "professionally" done. Someone hasn't done there job correctly.

 

I am going to try and find out where the issue is, maybe a leak down will help me.

[xt2005bonbon]

What is the color of the smoke? blue? white?

[Booki]

It is a white/grey smoke.