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Replaced all plugs and coils, still getting 13mpg


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I'm still getting an intermittent CEL for misfire on cyl 2 so to me it makes sense there's something wrong with only that cyl. Also my other mechanic thought the same thing, the pistons ring is bad.
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Wha do you fuel trims look like? A vacuum leak can cause the misfire as well as a bad injector. Both of those will affect your fuel economy as well. Ijust finished up a 2 month long witch hunt for a vac leak bc my idle LTFTs were at like 12-13, cel for cyl 1 misfire and I was getting crap boost numbers. Now after I found the issue, no cel, LTFTs are arpund 3-4, mpg is 23-24 and im hitting target boost every time. All for 8 bucks total in parts.

 

Take your time do it right my friend

 

Sent from my SPH-L720 using Tapatalk

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I could be wrong in this and im sure others will chime in but I thought normal relative psi was -9 to -12. Are you burning oil? When was the last time you checked the dip stick? Do you have an android device? If so there is a $25 Bluetooth obd 2 adapter that can be used with the torque app. A datalog would be real helpful right about now.

 

Sent from my SPH-L720 using Tapatalk

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yeah that's what he thinks, bad valves or piston rings

 

the plugs look fine

 

I'm going to try and get a datalog wednesday, I have the cable just need to get the right drivers set up (assuming the cable works)

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I don't think its rings! Valve seat will make it idle poor when cold. Then seem okay as it gets up to temp. That's at first. Over time it will burn the hole seat and kick misfire all the time! Seen this more times then I can count! Same thing with my GT. Poor fuel mileage and misfire code always the same cyl. If you have over 100,000 miles on that eng its time to adj the valves witch no one does cause of the cost to pull 4 cams and changing shims! You can do a leak down test on that cyl. Pull the heads and send them out to be reworked. At the same time check the end play in your turbo. If your still running stock VF40 you will most likely find end play and want to change out your turbo.
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This matches my symptoms!

I'm at 98k miles, I hope the turbo isn't bad.

 

upon further reasearch it sounds like the valves are burnt

I think the previous owner was an idiot and didn't take car of the car

 

what would/should a shop charge to do my valves?

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So you know, I'm the owner operator of Range Automotive in Somersworth New Hampshire. And I spent 25 years working for Subaru before opening my shop in 2007. If your turbo is okay and you have not done the timing belt do at 105k? Your looking at about 2,500.00 Parts labor and machine shop. If the timing belt, water pump and pulleys have been done you can knock 500.00 off that. Keep in mind if it needs to be ripped down now is the time for things like timing belt, water pump and pulley set as well as a good time to upgrade your turbo. God speed makes a 16G turbo for under 500.00. Hope this helps!! Good luck with it.
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This matches my symptoms!

I'm at 98k miles, I hope the turbo isn't bad.

 

upon further reasearch it sounds like the valves are burnt

I think the previous owner was an idiot and didn't take car of the car

 

what would/should a shop charge to do my valves?

 

 

Burnt valves are not caused by the previous owner not taking care of the car, they are caused by the timing flaw in the OEM MAP.

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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Burnt valves are not caused by the previous owner not taking care of the car, they are caused by the timing flaw in the OEM MAP.

 

that sucks, was there a recall? does the lemon law apply?

also am I going to have to retune the ECU if they pull the block?

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that sucks, was there a recall? does the lemon law apply?

also am I going to have to retune the ECU if they pull the block?

 

No recall. Not safely related.

Lemon law doesn't cover second owners or much beyond a truly troubled car.

 

You'll retune if you want to keep the car running well.

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It's an emissions thing, they keep the USDM turbo cars in closed loop (lean AFR's) longer while in boost. Because of there is not enough fuel to cool down the combustion = burnt valves.

 

This is the table you modify in your tune:

http://images.rvsmods.com/var/albums/Cars/LGT/Engine/ECU/Tuning/CL-to-OL-Delay/CL%20to%20OL%20Delay.PNG?m=1391928907

 

You can see the AFR difference instantly (and torque gain):

http://images.rvsmods.com/var/albums/Cars/LGT/Engine/ECU/Tuning/CL-to-OL-Delay/CL%20to%20OL%20Delay%20DynoGraph.png?m=1391928907

05 LGT 16G 14psi 290whp/30mpg (SOLD)

12 OBP Stock 130whp/27mpg@87 Oct

00 G20t GT28r 10psi 250whp/36mpg

22 Ascent STOCK

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Here's the thread about the flaw in the MAP. Mike told me of this back in 2008,when he first tuned my wagon. 5th gens have the same issue.

 

http://legacygt.com/forums/showthread.php/dangerous-cylinder-trims-5th-gen-lgts-193842.html

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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Here's the thread about the flaw in the MAP. Mike told me of this back in 2008,when he first tuned my wagon. 5th gens have the same issue.

 

http://legacygt.com/forums/showthread.php/dangerous-cylinder-trims-5th-gen-lgts-193842.html

 

Thanks looking into it!

05 LGT 16G 14psi 290whp/30mpg (SOLD)

12 OBP Stock 130whp/27mpg@87 Oct

00 G20t GT28r 10psi 250whp/36mpg

22 Ascent STOCK

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  • 3 weeks later...

So I took it to my mechanic and he wont do the repair because he thinks it's too risky. He thinks the pistons are scored and some of the other valves could be bad other than cyl 2. He thinks I should just replace the engine because I'll end up paying just as much to fix everything else.

 

Is this a valid concern? I could take it to someone else, fix the valves and sell it (maybe) but I'll be out the $4k I already put into it. It looks like reman'd engines are around $3800 which I can't really afford. I don't know what to do.

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My click here link has what you should do, new ej257 and rebuild your heads. Even that was a load of money...

 

Can you do some of the labor yourself ?

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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no I don't have the tools or means to do any of it unfortunately

 

also what's a good place to get a reman'd longblock? I've only seen a few places, with a google search, that even have these engines

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