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Old 08-08-2022, 04:54 PM   #1
AceKingNYC
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Member#: 406087
Join Date: Nov 2014
Chapter/Region: Tri-State
Location: New York City
Vehicle:
06 VF48 Wagon
WRB

Default Could a batch of bad gas cause all of this?!!

Hey all,

So i am in the middle of trying to figure out what is causing a rough idle, AFRs between 16-18, and the car to stall out when i give it gas during idle. I think I have it figured out but wanted to get some feedback on a batch of bad gas possible being the culprit, or if it was something building up over time.

2006 wrx wagon - perrin TBE, ID1000cc injectors, VF48 Turbo externally wastgated (turbosmart with GS piping), GS boost control solenoid, Walbro 255 fuel pump. Stock block internals, jdm 6 speed swap.

so the issues started while i was performing another repair:

I was having some pressure fluctuation on my clutch pedal so i swapped out the clutch master cylinder, bled it, adjusted the clutch pedal to a feel i was happy with. Drove the car around the block a few times. All was well with the world.

Then when I was leaving my friends house (where we did the repair), the car struggled to turn over. Eventually did but was idling super rough and my AFRs were going nuts, high 20s. So we began to diagnose. Since the TMIC had to come off, we double checked that it was on right, no leaks, all tight. Check.

We then thought maybe the throttle body was malfunctioning, swapped that out with my friends (he's parting his built FXT so everything was conveniently easily accessible or off the car already). With his on, same symptoms. So it wasn't my throttle body. Check

We check for vacuum leaks - find 2 tiny ones around clamp areas and button those up - but nothing major where this type of idling and AFR issue would be this bad. Check

We start feeling the connectors on the injectors and we cannot feel a ticking/pulsating on Injector 1 i believe (the one closest to the front bumper, passenger side). All others, we can feel ticking/pulsating so we suspect those are working as they should. So now we think it's an injector that is clogged or dead. We test the wiring with an injector test kit, all connectors are getting power. So, I swap out the injectors with another set of ID1000s (mine were the old design and these were the renewed design but from my research, the injectors are the same but just seat differently with the new design). Car idles better but AFRs are still wonky and giving it gas on idle i feel the car chokes big time, then the rpms kind of spike up a bit once i let off the gas.

We then swap out coil packs to see if there is an issue. Nothing. Swap out spark plugs. I last changed my plugs in Nov 2020. I had NGK OSC plugs and i put new OSC plugs in at that time. Plugs are SUPER black with buildup on there. (this is primarily a weekend car, and i drive it maybe once a week sometimes so between Nov 2020 and now I couldn't have put more than 5K on the car maybe?)

Next - take the walbro out of the gas tank. sock filter is super dark/black so i am thinking i've found my issue. We swap on my buddies walbro and filter and nada. Still! so now we are thinking, wtf is going on here.

yesterday he was fiddling with the car, and he told me he sprayed some carb cleaner into the intake (i think that is what he said, I was driving and i was trying to pay attention to the road bc i had a child in the car) and he says that when he did that the car idled much better and he was able to have someone press the gas pedal and it revved up to 5-6k without many issues. He said it was breaking up a bit but nothing like what we were experiencing before. He then suspected that there is not enough fuel reaching the motor and that the only thing we haven't swapped out is the in-tank fuel filter that sits above the Walbro. So, I ordered a new one today and will also tap into the fuel line with a fuel pressure gauge to see if there indeed is a lack of fuel making it to the clutch.

we have also looked at the o2 sensor. I only received a code when i unplugged the o2 and MAF if i recall. Other times i have read codes, there have been none but the car showed p0170 for the car running lean when i manually scan with my AP. As of now, it's not showing that code.

A few days before we did the clutch master cylinder, I filled up at my usual gas station, Shell, with 93 Octane. Right now the tank is 3/4 full.

Since everything that has to do with fuel has seemingly had an issue (injector possibly dead/clogged, black plugs, walbro sock filter super dark/back) can I suspect that the gas was total ****?

At this point, when I receive the in-tank filter - I plan to siphon out all of the gas, and unplug the fuel lines and crank all of the gas out of the lines and refill it fresh.

it's been an interesting few days trying to troubleshoot to say the least. Sorry for the super long post.
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Old 08-08-2022, 06:58 PM   #2
blurred
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Location: Toronto
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Go back and remove/reinstall your tmic. Check your intake/inlet as well. Sounds like you have a post maf leak and resulted from improper reinstallation of the tmic. All of the other stuff you did was most likely unnecessary.

I know you said you checked it, but its very easy to have it look and feel on but you missed the outlet for instance or tore the turbo inlet etc... this is why I suggest a full re/re to ensure you seat it correctly and/or find a torn coupler etc... Basically just re-do your work

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Old 08-08-2022, 07:51 PM   #3
AceKingNYC
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Default

I did. I removed the TMIC several times. Checked and felt around the hoses to ensure they were fully on. I even swapped my GS TMIC for my old sti tmic just for kicks (with different hoses). The inlet and tmic were on, no leaks. Itís def not tmic or inlet related, everything there is as it should be


Quote:
Originally Posted by blurred View Post
Go back and remove/reinstall your tmic. Check your intake/inlet as well. Sounds like you have a post maf leak and resulted from improper reinstallation of the tmic. All of the other stuff you did was most likely unnecessary.

I know you said you checked it, but its very easy to have it look and feel on but you missed the outlet for instance or tore the turbo inlet etc... this is why I suggest a full re/re to ensure you seat it correctly and/or find a torn coupler etc... Basically just re-do your work

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Old 08-08-2022, 09:24 PM   #4
blurred
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Quote:
Originally Posted by AceKingNYC View Post
I did. I removed the TMIC several times. Checked and felt around the hoses to ensure they were fully on. I even swapped my GS TMIC for my old sti tmic just for kicks (with different hoses). The inlet and tmic were on, no leaks. Itís def not tmic or inlet related, everything there is as it should be
Well running lean like that means air getting in after your maf....

If you want to check injectors undo each clip one by one, if idle doesn't change thar one is an issue.

For coil packs or plugs put a fresh set of plugs in, run it and then check them to see which cylinder has an issue.

I'll still go back to you have a vacuum leak. Maybe bpv isn't hooked in properly or you didnt put the gasket etc etc, many other things to check. You can speed it up by spraying brake cleaner on each injector, each hose, each coupler, etc to see if you can change idle wheel finding the leak


Edit: didn't realize you haven't ruled out fuel pump, fix that troubleshooting item first.

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Old 08-16-2022, 04:53 PM   #5
AceKingNYC
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Member#: 406087
Join Date: Nov 2014
Chapter/Region: Tri-State
Location: New York City
Vehicle:
06 VF48 Wagon
WRB

Default

so just to update the threat:

car is all fixed now. It was the in-tank fuel filter. the top half seems to have almost spun and dislodged from the metal bottom, so fuel was pouring out of the side and not allowing enough fuel to travel into the block. Part number: 42072FE020
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Old 09-28-2022, 12:51 PM   #6
TheOtherDave
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At idle what are your MAF readings.


Should be ~ 2.5 g/s *RPM/500
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Old 10-01-2022, 02:24 AM   #7
All4s
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Short answer is yes it can happen from bad gas. Did you go to a new or different gas station than normal? Trying to pin point parts is the wrong answer. You drove in the gas station just fine. Then when you took off it hesitated right away ya? Did it rain there recently?
I do not recommend draining it out yourself unless you know exactly what your doing cause you will blow yourself up. Drain the tank the ghetto way get most of it out. You can crack the lines open as well. Wait till everything is dry! Put 5 gallons of 100 octane drive light see if it changes hesitation. Good luck

Last edited by All4s; 10-01-2022 at 02:31 AM.
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Old 10-01-2022, 02:28 AM   #8
All4s
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Ive never heard of a fuel fiter doing that. Sounds like its clogged from bad gas. haha
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Old 10-01-2022, 02:49 PM   #9
umscooby
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Default

Im just confused about the original issue before the symptoms arose. "Pressure fluctuations in the clutch pedal" huh? Can you elablorate? "Adjusted the clutch to a feel I like" Again, huh? How did accomplish this or what did you "adjust"

Thanks,
UM
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