Lean WOT - good at half throttle (Boosted)

[blackedout_taco_stidham]

What can cause the engine to lean out when boost increases, assuming that the fuel delivery is functioning perfectly fine, I wanna do everything I can to try and fix it if in case it actually isn't the fuel pump/filter. Before I turned the boost up to 8psi and was just running off the wastegate spring at 5.8psi, it was great, mid to low 12s AFR while at full throttle, not a single issue, then right BEFORE installing the AEM boost/controller gauge it started acting up. Anything will be helpful, thanks in advance like always guys! could a failing stock AFR sensor (bank one sensor one) cause this? i've read a lil bit about putting the MAF in a larger housing/pipe than stock, will that help, or only be a bandaid?

Turbo'd ~8psi
MAF pre-turbo in stock housing
FPR source from first (IIRC) barb on the throttle body pre-throtle plate

like i said all was good before changing anything, then right before ANYTHING was changed, this started happening, before upping the boost a whole ~2psi

one thing i may try tonight is turning the boost back down to just the wastegate spring and see if that helps...i have setting A on the AEM as ~8psi, and setting B as just the wastegate spring pressure, so according to TiAL its 5.8psi...ill report back, but if anyone has any ideas that may be leading to this please shout it, i've got a lil less than 200 miles before my clutch is broken in and i can unleash the beast!

[671taco]

Originally Posted by blackedout_taco_stidham

What can cause the engine to lean out when boost increases, assuming that the fuel delivery is functioning perfectly fine, I wanna do everything I can to try and fix it if in case it actually isn't the fuel pump/filter. Before I turned the boost up to 8psi and was just running off the wastegate spring at 5.8psi, it was great, mid to low 12s AFR while at full throttle, not a single issue, then right BEFORE installing the AEM boost/controller gauge it started acting up. Anything will be helpful, thanks in advance like always guys! could a failing stock AFR sensor (bank one sensor one) cause this? i've read a lil bit about putting the MAF in a larger housing/pipe than stock, will that help, or only be a bandaid?

Turbo'd ~8psi
MAF pre-turbo in stock housing
FPR source from first (IIRC) barb on the throttle body pre-throtle plate

like i said all was good before changing anything, then right before ANYTHING was changed, this started happening, before upping the boost a whole ~2psi

one thing i may try tonight is turning the boost back down to just the wastegate spring and see if that helps...i have setting A on the AEM as ~8psi, and setting B as just the wastegate spring pressure, so according to TiAL its 5.8psi...ill report back, but if anyone has any ideas that may be leading to this please shout it, i've got a lil less than 200 miles before my clutch is broken in and i can unleash the beast!

Try hooking up your FPR source post throttle directly on the intake manifold.

[blackedout_taco_stidham]

thats how it was when i first put the turbo on and the idle was very erratic, and bounced up and down and also the AFRs did the same thing (duh) i am going to give it a shot anyways since a lot of stuff has changed since the initial install. But also it does see boost where it is, it just sees nothing at idle/throttle plate closed, whereas if it is post throttle plate it will see vacuum at idle (~17-18) and will pull fuel accordingly...idk, we'll see, im gunna try it out in a lil while and ill report back. thanks for the tip, i hope your right! sometimes its the simple stupid stuff that gets overlooked and causes the biggest headaches...

[blackedout_taco_stidham]

I just swapped it over to my vacuum block which is sourced post throttle plate and the idle was good and smooth just like normal, so that's good, I haven't driven it yet, but I noticed the exhaust started smoking pretty badly, so I swapped it back and smoke slightly went away, but was still there, once again put it back on the vacuum block and the smoke stayed minimal, so that's kinda wierd, its idling at ~14.7, and doesn't really smell like gas...I've never smelt burning oil before, what does burning oil smell like, and what does burning coolant smell like as well? It's got me a lil worried now...

Sent from my PC36100 using AutoGuide.Com Free App

[Yodaforce]

What are you reading the AFR from and is it stand alone?

[blackedout_taco_stidham]

AEM UEGO wideband, and yes it is standalone, nothing else tied into it. Same thing with the AEM boost controller/gauge (its both in one unit)

Just took it for a test spin and it seemed like it would lean out at even less boost, anything over 2psi it would go lean...I'm thinking more and more that its gunna end up being a tired old fuel pump...or the fuel filter is clogged...damn

Also it looks like the smoke is gone, really hope it was a fluke...*crosses fingers*

Sent from my PC36100 using AutoGuide.Com Free App

[671taco]

Originally Posted by blackedout_taco_stidham

AEM UEGO wideband, and yes it is standalone, nothing else tied into it. Same thing with the AEM boost controller/gauge (its both in one unit)

Just took it for a test spin and it seemed like it would lean out at even less boost, anything over 2psi it would go lean...I'm thinking more and more that its gunna end up being a tired old fuel pump...or the fuel filter is clogged...damn

Also it looks like the smoke is gone, really hope it was a fluke...*crosses fingers*

Sent from my PC36100 using AutoGuide.Com Free App

I recommend to swap out the fuel filter first...then the pump next.

[blackedout_taco_stidham]

Originally Posted by 671taco

I recommend to swap out the fuel filter first...then the pump next.

I think that will be my POA.

Does anyone have any other ideas as to what it could be?

Sent from my PC36100 using AutoGuide.Com Free App

[671taco]

Are you still having exhaust leak problems?

[blackedout_taco_stidham]

Originally Posted by 671taco

Are you still having exhaust leak problems?

Nope, atleast not that I know of, I fixed the two I could feel/hear and it fixed my idle/cruise AFR...so Im assuming no

Sent from my PC36100 using AutoGuide.Com Free App