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p0108&p0463 suddenly car wont start 05 legacy 2.5


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My grilfriends 05 legacy refused to start this morning. engine turns and you can get it to fire once but wont run. i pulled the codes and got p0108 and p0463 the car had no engine lights prior to this morning.

 

p0108 comes back as Map pressure circuit high

 

and p0463 fuel level voltage high

 

The fuel gauge appeared to work till 2-3 attempts to start the vehicle then that dropped to zero. there is fuel in the tank, in fact its full the car was just filled up the night before. Apparently after filling up the car ran a bit rough at slow speeds but made it home.

 

Unlike my older subarus the MAP sensor is not on the strut tower. So p0108 is refering to the sensor in the intake by the airfilter? is there a way to test if this is bad. I can't find any vacume leaks or disconected hoses/wires.

 

I pulled the line before the engine  and turned the key foreward some fuel gushed out not a crazy amount so I am getting fuel and the pump is running. Spark plugs where done about 3 months ago. Should i order a new MAP sensor or blame the fuel pump getting "weak"?

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Since the fuel guage dropped that sounds like it may have blown a fuse. Check all the fuses and fusible links.

 

There is a problem with the 00-04 fuel pump assembly's that bleeds off the fuel pressure back into the tank. It causes poor drivability and starting problems, then eventually the engine won't start at all. Search for " fuel pump cap o-ring".

 

I don't know if they carried the same fuel pump design into 05, but its a possibility. I would check fuel pressure with a guage to be sure its ok. You could also pull the pump assembly to inspect it.

 

Try clearing the codes and see what comes back.

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did not check fuses yet will deffinetly in the morning. didn't think they would be blown since it was moving fuel when i pulled the line and turned the key to the run position. I do actualy have the pump out of the car as i was hopping something obvious would jump out at me but this assembly is nothing like my 98 rs what could i look for?

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I know the flaw in the 00-04 pumps is very obvious if you pull the pump. You know something's not right just by lookin at it. There's a round metal cap that will crack on the side by the tabs that hold it on and the oring that seals it will pop out.

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okay after pulling the pump that looked like a large complicated bucket compared to what I'm use to in my impreza I opted to replace and hope that was it. the car started after about 5-6 primes no problem drove around town and to work. started just fine 8 hrs later. this morning when starting the rpms dropped for a second and then returned to normal. so I sent her on her way to work with my gf and after she stopped for coffe it would not start again. so I have to drive 45 min after work tonight to see if I can coax one more start out and get it home.

 

as for rodent damage a few months back they chewed the firewall insulation I immediately set traps every day didn't notice any other damage

Edited by sirrobert09
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I don't know exactly which wires on an 05. On the older cars there were 6 wires, and the power and ground for the pump were the two largest wires.

 

Did you replace just the pump or the entire assembly?

i replaced the entire assembly since the gauge was being wiped out as well. This time the gauge still works but no wine from the pump after being driven for a day with many on off cycles then one drive to actual work and it doesnt start back up nor does the pump make any noise

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just an update tested the harness from the car got 12v tested pin 5/6 with a direct power of 12v pump made a click but would not turn. Returned for a replacement. Should be in tomorrow hopefully before I have to go to work.

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Does the fuel in the tank smell strange?

Kinda wondering if somebody bleached your tank.

Doesn't make much sense for a pump and the gauge sender to burn out at the same time, and then have a brand new pump burn out in a day.

I know aftermarket pumps don't have the best track record, but you usually get at least a few months out of them.

 

Might also check the pins in the connector for corrosion as that can cause the pump to run hot if it can't get the proper amount of current.

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okay so I just put the new new fuel pump in fired right up. If i causualy increase throttle it runs fine but if i hit the throttle fast it kinda chokes before reving up. Is it possible that my new plugs have been fouled just replaced them before winter? or is there something else i can check?

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Subaru OEM or aftermarket?

 

I remember the damper/regulator do-hickes now.

 

If you want to pull the plugs and check them it cant hurt. Next I'd probably put a fuel pressure guage on it and make sure that's up to spec.

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wasnt able to get ahold of my uncle with the pressure gauge..... did pull the plugs saw a bit of oil seaping through the spark plug seals replaced those and plugs  made zero difference still stutters and chokes when hit with full throttle or any amount of reasonable throttle from idle any thing over about 2,500  rpms it doesn't stutter from.

 

Tried running the tourqe app on my phone with it  just to see if i could find anything realy noticable aside from the the o2 sensor curves didnt realy match what I see on my other cars seemed more stable and flat then my wrx  with very little changes. Was listening to the injectors with  a screw driver to the ear could hear them all fireing sounded okay. any chance the pressure regulator by the firewall could cause the issues?

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So the battle still continues Replaced plugs and wires still no luck. when watching the timing advance and the torque app right when it stutters the timing jump from the normal idle of about 15 degrees advanced to any where from -9 to -2 soon as it passes that point jumps back up to 15-20.  So is the car detecting a knock at low RPMS and just pulling the timing like crazy?
 
Here is a video i took

 

 

https://www.youtube.com/watch?v=9xhoonBNixg

Edited by sirrobert09
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