Shifting and idle issues with EJ20 swap, and OBDII port doesn't work

[Dake]

Guys, I'm at a loss and need some help. I just finished swapping an EJ20 into my daily driven 2003 Forester to get it on the road again. It's an eBay engine that I pulled from a t-boned 99 Forester 5 speed. The 99 ran, drove, and idled fine. My 03 automatic did too, but overheated fast.

We swapped the EJ20 into my 03, retaining the 03's intake, airbox, ECU, etc. After the ECU re-learn process it runs and idles fine, until I go to drive it. When I shift into reverse the RPMs dip to under 500 for about 5 seconds until it realizes it's in reverse, then they go back to proper idle. In drive, it shifts at all the wrong times and won't downshift if I floor it. When I stop again and put it in park, the idle shoots to 2500+ and doesn't go back down until I turn the car off for awhile.

Also, weirdly, the OBD2 port won't work. I tried to scan the CEL and the scanner wouldn't detect the car. I've checked grounds, fuses, and connections especially those related to a non-working OBD2 port. I haven't gone too far down that road yet because I suspect something worse is going on.

Something must be getting confused in the ECU/TCM department, right? I'm starting to worry that this engine and trans are not compatible. Anyone have any ideas?

 

[Bushwick]

As far as OBDII ports go, I've had a Ford and Saab both run into issues where the wire crimps at the back of OBD connector (car connector) can back out slightly. Seems to be a design flaw. It'll work perfectly, then won't work/connect to the scanner. FWIW, both cars in question had the exact same issue of of crimps backing out, in two different states, with completely different scanners, years apart.

 

My advice to rule the connector out, is unscrew it from the under dash, etc. and let it hang. All the crimps on the wires SHOULD be in unison, like soldiers in a row. If any are even slightly off, it can lead to a no connection issue. In the two cars I had this happen with, I'd go ahead and insert the reader connector, then manually push each crimp forward into the OBD II port. Every time the scanner would then read it.

 

As far as shift points go, you had an ej25 dohc? And now have an ej20 sohc? Shift points I imagine are very different considering their powerbands are different. Hopefully someone more knowledgeable can help.