I Purchased an 05 Legacy that Barely Runs

[SubaruLemon]

After 233K miles, my current Subaru WRX is at the end of it's useful life so I decided to try my luck with a Legacy GT. I found an 05 GT with ~80K miles and a decent body. However, the previous owner told me that it needed head gaskets. I felt the price was fair given the assumed condition of the car so I took the bait. 

Problem is, I'm not convinced the car needs headgaskets. We have performed a head gasket test with the kit that looks for combustion gas in the coolant, tested negative several times. No bubbles in the coolant. Looked inside the cylinders with a scope, no signs of water, the cylinders actually have a ton of carbon build up in them. Compression is around 115-120 for all cylinders, a little low, but I think it should still run fine. 

So what are the symptoms? When you first start the car cold, it runs absolutely terrible. It barely runs, very rich exhaust, smell of unburned fuel, engine shakes terribly. No change in the engine RPM or performance if you hit the accelerator.  If you try to drive it, it does not move. It does this for about 10-15 minutes until it warms up. Once it's warmed up, it runs a lot better, but still has a misfire in I believe cylinder 2 (front left) but you can drive it. There is no change in RPM if you disconnect the coil pack or injector from this cylinder, car is essentially running on 3 cylinders when it's warmed up.

 The timing belt was changed 8K miles ago, so I don't think it's that, as I'm not sure the symptoms would improve when it's warmed up. In addition, the previous owner said it ran fine for a year after the timing belt job. It appears the previous owner also installed four new coils and installed a new used fuel injector in cylinder 2. I did a compression test, about 115-120 psi in all four cylinder. Scoped the cylinders, has a ton of carbon in them, two are very bad (#2 & #3), but no evidence of moisture/water in them. Changed the plugs - no improvement. Checked the fuel pressure when the car is cold, ~45 psi. I also checked for power, ground, and or signal on the coil wiring and  injector wiring using a test-light, seemed okay. The only codes I'm getting now are cylinder 2 & 3 misfire once it's warmed up and running. I was getting a code for the intake runner/flapper as that wasn't installed correctly but we corrected that and the code is gone. This evening I pumped the coolant system up to 15 psi and left a gauge on it to see if it drops. I also took the O2 sensor out of the exhaust before the turbo to see if it ran better incase one of the cats were clogged - no luck. Not sure if it matters, but the oil also kinda smells like gas. 

I'll probably try to swap the coil and or injector  in cylinder #2 tomorrow to see if that helps the car run better once it's warmed up. 

If anyone has experienced any similar symptoms or have any ideas, your help is appreciated. 

Thanks, 

Bobby 

 

[seanyb505]

Sounds like a good plan on the injector/coil swap. Only swap one piece at a time, and know you're looking for the problem to show up elsewhere not be eliminated. 

[Max Capacity]

These cars are finicky if you don't use the right brand of parts. OEM or NGK coils, NGK spark plugs. gapped at .028"

Is your tranny a 5mt or 5eat ?

You'll want to verify it's not a Gates timing belt kit, they are junk. Aisin, is the only one you want.

You'll want to verify the small black o-rings seal between the plastic intake manifold and TVG's have been changed to the newer (2007) larger orange o-rings. zoom in to the second photo, above #2 injector, see the orange tab.

Use MAF cleaner to spray up inside the MAF sensor on the air intake tube just after the air filter.

Make sure both engine ground wires are in good shape, they area a known issue. You can make your own. third photo.

 

[KZJonny]

Poor job installing the timing belt, and it has skipped a tooth? (Ie, ran fine for a while but if tensioner + belt guides are not installed correctly…. It may have jumped a tooth or two on the 2/3 side?)

Not likely if auto. Possibility if MT.

[Max Capacity]

You can find the 05 service manual here,

https://people.csail.mit.edu/ilh/vacation/

[KZJonny]

Also: fingers crossed for you dude. Finding a low mile LGT that only needs new coil + plugs + maybe timing is a steal. (Assuming you got it for blown head gasket pricing.)

Good luck!

[SubaruLemon]

Thanks for all the suggestions guys. Also, the car is an automatic unfortunately. 

Cylinder #2 seems to be intermittent when warmed up. Yesterday, you could hear a difference in RPM when the existing coil was disconnected. I swapped the coil anyway and no real improvement. I took the new coil out and put the existing one back in last night and now today there is no change when the coil is disconnected. 

Anyway, I've been focusing mainly on how bad the car runs when the engine is cold and not warmed up. Again, you can't drive the car when it's cold, there is no change in RPM when you give it gas. I happened to notice with my scanner that the MAF is measuring ~16 g/s at idle and the fuel injector pulse was also high, 6 ms. Once the car warms up and starts running better, the MAF measurement drops to ~3-4 g/s at idle and the fuel injector pulse drops down to 2 ms. If I increase the RPM to 3K (when warm) I see roughtly the same MAF measurements of 16 g/s and also a higher injector pulse, similar to when the car is cold and running terribly. I was hoping maybe a faulty MAF but this didn't really add up since the engine does run better, still misses but is better, when it's warmed up. i has a spare so I swapped MAF's with my WRX, no change in the legacy and the WRX ran fine with the Legacy MAF. 

Regarding the intake manifold gaskets, I'm not sure what color the manifold gaskets are. However, i sprayed the area with carb cleaner and no change in RPM. I then did a smoke test, which only showed me that my intercooler is leaking where the aluminum heat exchanger meets the plastic end. 

The next thing I tried was a vacuum test. When the car is cold and running bad, there is less than 5 psi of vacuum. However, once the car warms up the vacuum increases to ~16-18 psi of vacuum and the engine runs better. Was thinking maybe the valves aren't seating until it warms up, or maybe the timing belt did jump a tooth. But if the timing did jump, I'm not sure why it would get better to the point that you could drive the car ,with a misfire, when it's warmed up. Maybe the valves aren't seating when cold but once it's warmed up, they seat somewhat better. Grasping at straws at this point.  

Bobby 

[seanyb505]

Can you perform a leak down test?

And did you switch injectors around? 

[SubaruLemon]

 

5 minutes ago, seanyb505 said:

Can you perform a leak down test?

And did you switch injectors around? 

I think I can perform one, just have to figure out TDC on each cylinder. 

I did not switch the injectors around yet, will probably try that soon. I did listen to injector 2 with a stethoscope and could here injector 2 clicking, doesn't mean it's not clogged. 

 

[SubaruLemon]

22 hours ago, Max Capacity said:

You can find the 05 service manual here,

https://people.csail.mit.edu/ilh/vacation/

Thanks for this, will be very helpful. 

[Max Capacity]

Your welcome, make sure your in the correct section for GT engines. 

[SubaruLemon]

So we checked the timing belt, which was off one tooth. When we started the car, it ran perfect BUT the alternator belt was still off. The car was put back together completely (alternator belt on) and the car runs terrible again. If I disconnect the harness from the alternator, the car run great. However, as soon as I plug the harness back into the alternator, the car barely continues to run. I also used jumper cables to ground the battery to the frame and to the engine, no improvement. 

Has anyone ever seen this? Any ideas? 

[Max Capacity]

Wow, that's a new one.  First, I'd check the battery terminals and harness to the ALT.

You might want to PM cardoc over on outback.org.  You can get him from post #6 here, https://www.subaruoutback.org/threads/evap-line-fuel-tank-repair.563007/#post-6428842

 

 

[subisubisu]

15 minutes ago, SubaruLemon said:

So we checked the timing belt, which was off one tooth. When we started the car, it ran perfect BUT the alternator belt was still off. The car was put back together completely (alternator belt on) and the car runs terrible again. If I disconnect the harness from the alternator, the car run great. However, as soon as I plug the harness back into the alternator, the car barely continues to run. I also used jumper cables to ground the battery to the frame and to the engine, no improvement. 

Has anyone ever seen this? Any ideas? 

Please clarify - did you correct the timing belt to be aligned with the marks so that now it runs well with the alternator belt off?  Or did you leave the timing belt off by one tooth?

Probably not your situation, but elsewhere in the forum you can find mention of a practice of setting the timing off of the marks when swapping the cylinder heads for ones from a more recent engine.  If yours is all-original it won't apply to you.

 

[rhino6303]

20 minutes ago, SubaruLemon said:

So we checked the timing belt, which was off one tooth. When we started the car, it ran perfect BUT the alternator belt was still off. The car was put back together completely (alternator belt on) and the car runs terrible again. If I disconnect the harness from the alternator, the car run great. However, as soon as I plug the harness back into the alternator, the car barely continues to run. I also used jumper cables to ground the battery to the frame and to the engine, no improvement. 

Has anyone ever seen this? Any ideas? 

Your alternator could have a bad diode and be leaking ac voltage. It's a fairly simple test. In theory, the ac signal could be screwing up the crank signal causing misfires and such.

https://youtu.be/1c8uD1C6WNk?si=kfd-ZCnT-t1VqrfD

[SubaruLemon]

16 hours ago, Max Capacity said:

Wow, that's a new one.  First, I'd check the battery terminals and harness to the ALT.

You might want to PM cardoc over on outback.org.  You can get him from post #6 here, https://www.subaruoutback.org/threads/evap-line-fuel-tank-repair.563007/#post-6428842

 

 

Thanks, I plan to do some more trouleshooting today on the harness. If I have no luck, maybe I'll send him a PM. 

 

16 hours ago, subisubisu said:

Please clarify - did you correct the timing belt to be aligned with the marks so that now it runs well with the alternator belt off?  Or did you leave the timing belt off by one tooth?

Probably not your situation, but elsewhere in the forum you can find mention of a practice of setting the timing off of the marks when swapping the cylinder heads for ones from a more recent engine.  If yours is all-original it won't apply to you.

 

Yes, we corrected the timing belt alignment and it seems to run fine with the alternator belt off. I'm not sure if the timing belt adjustment made any improvements or not as we just stumbled upon this alternator issue causing the car to run bad. 

I believe the engine to be original. 

16 hours ago, rhino6303 said:

Your alternator could have a bad diode and be leaking ac voltage. It's a fairly simple test. In theory, the ac signal could be screwing up the crank signal causing misfires and such.

https://youtu.be/1c8uD1C6WNk?si=kfd-ZCnT-t1VqrfD

 

I tried replacing the alternator with no luck. Found some guy on another forum with a similar issue in his outback. He found a bad 7.5 amp fuse blown in the fuse box for the signal wire.  

[SubaruLemon]

So I found the alternator fuse, which was good, replaced it anyway and no improvement. Compared voltage going to the alternator car off and running, which was similar to what I had on my WRX. 

Next I moved to the ECU, which appears to have been replaced once before (Marker Writing on Side). I opened it up and looked at board and noticed the hot spot shown below. 

 

[KZJonny]

On 12/26/2023 at 2:51 PM, SubaruLemon said:

So I found the alternator fuse, which was good, replaced it anyway and no improvement. Compared voltage going to the alternator car off and running, which was similar to what I had on my WRX. 

Next I moved to the ECU, which appears to have been replaced once before (Marker Writing on Side). I opened it up and looked at board and noticed the hot spot shown below. 

 

Old eyes. Small photo. Can't see the hot spot.

I think you said you are an AT car? (EDIT: Yes, I see that you are, I can read, apparently.) Worst case, let me know I have an 05 AT ECM kicking around the parts bin somewhere, and will never own an AT car. If you need it, I'd do mates rates + shipping.

Edited December 28, 2023 by KZJonny

[Deltaking]

Ok just a question. You have physically checked the coil cables... My car had strange things happening and I have misses mainly on cyl 2 & 3 yet I found that coil 4 cables were torn and I could actually hear an arc sound as the open wire was arcing on the engine case. I soldered it up then taped up all the coil pack wires as well as the clip which clips onto the coil pack.

 

On the spark plugs just double check them too I had a fail as well on that... I was give a spark plug not OEM but NGK and it was installed and the car still ran bad... make sure the reach of the spark plug is 26.5mm and that it is a 5kOhm spark plug.

Edited December 28, 2023 by Deltaking

[SubaruLemon]

On 12/28/2023 at 11:47 AM, KZJonny said:

Old eyes. Small photo. Can't see the hot spot.

I think you said you are an AT car? (EDIT: Yes, I see that you are, I can read, apparently.) Worst case, let me know I have an 05 AT ECM kicking around the parts bin somewhere, and will never own an AT car. If you need it, I'd do mates rates + shipping.

Wish I seen this sooner, I ordered a used one offline on Wednesday Moning. If for some reason I don't recieve it, I will reach out. Thanks for the offer. 

 

On 12/28/2023 at 1:22 PM, Deltaking said:

Ok just a question. You have physically checked the coil cables... My car had strange things happening and I have misses mainly on cyl 2 & 3 yet I found that coil 4 cables were torn and I could actually hear an arc sound as the open wire was arcing on the engine case. I soldered it up then taped up all the coil pack wires as well as the clip which clips onto the coil pack.

 

On the spark plugs just double check them too I had a fail as well on that... I was give a spark plug not OEM but NGK and it was installed and the car still ran bad... make sure the reach of the spark plug is 26.5mm and that it is a 5kOhm spark plug.

Thanks for the suggestion. I haven't heard heard any arc sounds and the wires look in good shape, but one could use a new plug. Unfortunately, I don't think that's my problem.  

Will double check the plugs if the computer doesn't work. 

[silverton]

On 12/14/2023 at 5:23 PM, SubaruLemon said:

Compression is around 115-120 for all cylinders, a little low, but I think it should still run fine.

That's a bit low there buddy. Even if we're aiming for the middle spec of 156.5, you're 24% under. but doesn't really explain why it falls on its face with the alternator harness plugged in.  Have you replaced the alternator yet? Have you checked voltage at the alternator while its running? Or the battery itself?  Battery starts the car, alternator keeps it started.  a battery will keep a car running for a short time though.

Edited December 29, 2023 by silverton