Hi guys. I'm doing a motor swap in my buddies 97 legacywith a ej25. I got a 96 ej25 motor in and it runs but is surging at low idle. Then eventually will die. I had the motor out and re did all the gaskets. I am stumped. Can anyone help??

Sounds like the IAC hose, large 1" one is off.

All the vacuum lines are hooked up. The big ones and the small ones but still runs like there's a big vacuum leaks but I can't hear anything hissing

idle controller

or

vacuum leak - ifhooked up it could sitll be a cracked hose, etc

 

spray some carb cleaner around while it's running - if oyu hit a leak it'll surge like mad.

If it has the box airbox that attaches to the throttle body make sure the bottom clips are seated together properly.

 

Throttle cable too tight can cause problems with initial startup, make sure it has a little bit of slack so it's not pulling the lever.

 

Did you remove the fuel rails from the manifold? If so did you replace the fuel injector o-rings and the fuel rail o-rings?

This is just a remote possibility, but have you checked to see if the ECU numbers are the same?  According to Subaruparts.com, they are different numbers.
The '96 EJ25 DOHC was a one year only engine with hydraulic lifters rather than solid.  The valves are significantly shorter on the '96.

 

Just a thought.

It's a timing issue. I've retimed it and now I can't get the cams to not move when I'm putting the belt on. I get one side fine and move to the other side and then everything moves agai. But with the ecu. I've heard of people having the 96 motor on the 97 ecu. And the fuel rail I've replaced the injector gaskets I've replaced every gaske.

Thanks guys!

pointing me in the right direction is a big help. Thanks again!

It's a timing issue. I've retimed it and now I can't get the cams to not move when I'm putting the belt on. I get one side fine and move to the other side and then everything moves agai. But with the ecu. I've heard of people having the 96 motor on the 97 ecu. And the fuel rail I've replaced the injector gaskets I've replaced every gaske.

Thanks guys!

pointing me in the right direction is a big help. Thanks again!

 

You need to hold the drivers side cams.

 

Spring clamps and a couple 17mm wrenches help/

But then I put tension on the belt and they spin

What do you do with the wrenches? I've used the clamps