Just finished up my '99 Legacy SUS EJ22E swap. Motor runs great, solid idle at 700 RPM and 3% load. Before I started it, I left the engine wiring connectors unplugged and rolled the motor over for oil pressure. When I first started the car it was running great but at a 2000 RPM idle, after a while it dropped down but shook like an old diesel. Front catalytic converter was glowing red but they are both in new and it had a break in procedure. I increased the engine speed to 2,500 RPM for the break in period ( 2 mins ). When I got it back down to idle speed, it roughened up and quit. Re started it and it would not idle. I held it at 1k RPM for a min and then it began to idle smooth at 700 RPM, engine temp does not go over 199* when the fan comes on or below 196* so I thought it just needed some running time. Drove it around some and it was running great, then as I came up a large hill, it lost a bit of power and then began to missfire above 30% load. I had a freeze frame for P0301 at 51% load 37 MPH, open loop due to engine load.. Now driving with the laptop and watching the load, I'm getting missfires right at 30% load and up. sometimes it seems to start around 28%

 

Codes are

 

P0301-4 and P1507. CEL does not flash all the time during missfires. I have not cleaned the idle air control yet but a solid 700 RPM idle tells me that's most likely not it

 

Current repair/ maint list is

1996 EJ22E swap- retained wiring, cam and crank sensors from EJ25D, all other sensors are from the 1996 engine

New head gaskets, timing set w/ water pump. Spark plugs ( NGK ) and a new coil. I reused the plug wires on the '96 as they are the blue NGK's and in good shape

Both front and rear Catalytic converters, both O2 sensors ( Bosch )

New Air cleaner element

 

Any insight?

Edited May 26, 201312 yr by matt167

Have you pressure washed the engine?

 

I've seen this problem with water in the spark plug wells.

Had a used engine that had a bad injector.  Rough idle.

Fuel Pressure?

Could it idle smooth with a bad injector?. It stays solid on 700 RPM.. As far as pressure washing, I have not but I did clean the engine up before install and that included carb cleaner and PB blaster when I cleaned the cylinder head mating surfaces..

 

They are grey top injectors and the EJ25 had red tops. should I swap them?. Have not checked the fuel pressure yet as I do not have an EFI gauge but I was going to get a fuel filter because that's the last filter that is before my ownership

Edited May 27, 201312 yr by matt167

Grey/red injectors shouldn't matter.

Hardly any difference between grey and red injectors.

 

The 1507 code may be present because the ECU was not allowed to set the idle speed during the initial startup. I would reset the ECU (unhook the battery for ten minutes), allow it to learn idle fuel/air mapping (don't use the throttle to keep it running, if it stalls just restart it), and see what comes back.

 

If the misfiring continues pull the plugs and check them for signs of fouling.

I Will do just that. Makes sense and hopefully it is the issue. I think it is ECU related because it runs so good otherwise.. Only other guess is that the timing jumped a tooth, but I think it would have a rough idle then

Edited May 27, 201312 yr by matt167

Well, I did just that and so far so good. The drive was not that far but I waited for the engine idle to settle where it had set before ( 700 RPM ) and made sure it was in closed loop before I took off. I was able to achieve 4K RPM coming up the hill. No CEL at all.. Hopefully all is well and it was a glitch from giving it gas when it needed to do it's thing

Went for a longer drive and it's still running fine. 4K RPM up the hill with no issue

Have you considered the knock sensor?

feul pump or injectors sat to long or main engine harness not pluged in all the way or engine main ground on intake or bad maf senser or bleed down valve train lifters sticking or out of time

Have you considered the knock sensor?

Brand new. When I watched it on my computer, ignition timing advanced until it started missfiring and then the timing pulled back so the knock sensor is working properly I think

feul pump or injectors sat to long or main engine harness not pluged in all the way or engine main ground on intake or bad maf senser or bleed down valve train lifters sticking or out of time

Could be the injectors had a hickup as the engine was a junkyard engine.. In any case it seems to run fine now, so that reset fixed it.