Post Rebuild issues

[xX6TheGoose9Xx]

Over this last summer one of my cylinders was doing a compression of 0-20 both cold and warm. Rebuilt heads (machined and held vaccum) and swapped shortblock with new crawford OEM shortblock. Got car back 2 weeks ago and on the drive home threw code p0021. Replaced that oil valve, no issues, drove it around after that and no issues. Week later drove it around and have both misfires in cylinders 1-3. Shop double checked work was holding compression and everything. Everything is stock except for cobb AP and grimspeed tmic. Would it just be the coil packs they're new OEM but sat for 4-5 months. Any help is greatly appreciated.

[Tehnation]

oh sounds like my issue. Looks like an issue with the passenger side of the intake possibly.

 

Better check for a vacuum/boost leak, maybe near the intake manifold and tgv gaskets. Cap of the intake with a 3" pvc rubber cap and band, then push some air into the system and listen for leaks. Soapy water helps to isolate the area.

Do you have top feed or side feed? Probably side feed, can't remember how those work, but I would inspect that as well to make sure they are seated properly.

 

To test the coil packs swap one from passenger side with driver side to see if the code moves.

Edited January 19, 2022 by Tehnation

[silverton]

https://motoiq.com/the-dreaded-subaru-p0011-and-p0021-dtc-codes-dont-let-them-wreck-your-turbo/2/

[Pleides]

Did you take your banjo bolt filters out when rebuilding the engine? They shouldn't be there from new, you DEFINITELY do not want them in your car when your rebuilt engine sheds metal as it breaks in.

[xX6TheGoose9Xx]

Have yet to check vaccum leaks or any sparkplug work. Injectors are side feed DW 1000cc injectors( forgot to mention that)Did a datalog before replaced oil control valve tuner said that oil valve was halfway open halfway closed. SOOO replaced that oil control valve, still throwing code. I personally made sure to take banjo filters out during rebuild in both avcs and turbo lines along with new copper washers. Yesterday was really cold out battery died (one year old) replaced battery let it idle for 10 minutes and now whenever I stop it idles out and dies. This weekend I will disconnect battery and verify the right idle learn procedure. I'm going to also check the spark plugs for oil on electrode and spark gap. On cold start the Cobb AP cylinder 1-3 roughness will spike up to 10-15, but after several minutes 0 roughness on both. Theres no blue smoke, and it smokes a fair bit but its a single exaust and its been colder than usual the last couple of days. Feels like a nightmare. Will work on it this weekend. keep posted, thanks in advance!.

[Max Capacity]

After resetting my ECU, I always drive the car, I don't let it sit and idle.

 

1000cc injectors and stock downpipe ?

[Infosecdad]

When relearning idle, I follow the recommended steps for turning off all accessories, headlights, etc. Start it and just let it idle for 8-10 min, then it should be fine there.

 

Cold start and Cyl 1-3 might point to a TGV issue, since those are used when cold and it's on the same bank. Could be the TGV's themselves or a gasket.

 

Did you get an OEM OCV? We've seen several aftermarkets fail out of the box, it's one of the parts that should be OEM (like thermostat, radiator caps, O2, etc).

[xX6TheGoose9Xx]

Its stock downpipe, but it has the single exaust conversion. I checked the spark plugs and theres no oil on them. I checked for vaccum leaks and couldnt hear anything. I redid the idle relearn procedure and drove it and it was fine. During the idle relearn, when I did the hot start, check engine light came on along with all four cylinders misfiring and the random misfire code. I checked all the roughness and the highest count on cylinder one was 4 and on the other cylinders it only got up to 1-2. As soon as I hit the road no roughness at all. On the AP the A/F ratio is right 11-12 under load and 14.7 during idle and light accel. Been talking with family friends, they were telling me the wiring harness itself could be bad. Since theres no distribtor, and brand new coil packs spark plugs and fuel injectors it may just be the harness itself,grounding to something. Ill post a photo later. I dont have any issues with It leaning out so I think I could rule out a fuel pump issue. The harness is the original 17 years old and has dirt and grime all over the connectors. Otherwise I feel like Ill be wasting time and fuel trying to reset the code and drive until the monitors are set only for the code to come back up on a cold start. Its a brand new shortblock, could the misfires just be from that inital crank and the rings not being 100% seated yet.

[xX6TheGoose9Xx]

All of the sensors are OEM

[Tehnation]

I keep forgetting about working tgvs, I deleted mine. Do the tgvs throw a code when they are bad? Or could they not work and cause a misfire code without triggering the tgv code?