legacycentral bbs

Hello everyone,

So after making the decision to swap my blown engine for a new one I've run into some problems.


Today was the first time I fired up the new engine and I'm having some big issues. So here's my problem. The engine races up to about 2500 at Idle.

When the car is first turned on I get Code 32 for my O2 sensor. I don't really know why this is coming out but I figure I can check the resistance and see what's going on.

After a few minutes the car will bog down to about 1000, and shoot back up to 2500 a second later. At this point, it will spit new codes:

24 and 22 IAC Valve and Knock sensor.

I know I need to replace my vacuum hoses, they're hard and cracking near the ends, I'll be doing that tomorrow.

I want to check the IAC valve, I was told that if it's functioning properly, when I unplug it the motor should die, I'm not sure how accurate that is. I've also got the FSM so I'll look in there for a diagnostic procedure as well.

The knock sensor, I figure I can just change to the Knock sensor on the engine I swapped from it was working up until the motor blew so I figure there's no reason it shouldn't be working now.

Am I missing anything here or am I on the right track for these issues?

Regarding the high idle, have you checked to make sure the throttle cable is not tight and the throttle plate is fully closed?

Does the throttle body have this screw on it?

http://www.main.experiencetherave.com/subaru/images/tb/

Check to make sure you don't have any vacuum leaks. Regarding the IAC valve, if you unplug the electrical connector the idle would typically increase assuming you were at a normal idle speed.

I recommend trying to tackle only one issue at a time. Try and get your high idle issue sorted out and then worry about the knock sensor code if it's still present. I recommend using the green diagnostic connectors to do the "active" check.

Josh thanks for the quick reply. I changed the hoses and the knock sensor just now that cleared up the 32 22 and 24 but the idle is still racing. Yes I do have that screw on the throttle body but I've never touched any of those screwes. I had to move my throttle body over to the new engine, but I never fiddled with any of those set screws. All I did was remove the TPS so as not to get it soaked with Cleaner spray.


Now I have a code 2. I'm about to start researching that. According to a Subaru Master Tech a Code 2 is nothing to worry about. He suggested resetting the ECU. I pulled the ECU fuse and tomorrow morning I'll go through the resetting process.

If that doesn't resolve it, I figure my next step will be to check the TPS for continuity and such and also cleaning the IAC valve.

Issue resolved.

I replaced the Idle Air control valve with the known working part from my previous motor. Immediately upon starting my Idle RPMs were around 1,000 to 750. The Idle was a bit rough but after some adjusting of the TPS everything smoothed out and came together nicely.

You do know that there is only one adjustment on the TPS you should make? The link below shows how to adjust the idle switch. You should make no other adjustments to the TPS other than the one listed below.


http://main.experiencetherave.com/subar ... sting3.jpg

So what I did was unscrew the set screws that hold the TPS in place and rotated it on it's axis until I reached an idle of about 750 rpm as the FSM suggests.... Is that wrong? What are the consequences of doing so?

I know that by rotating the TPS I'm opening the flange in the throttle body a few thousandths.

Did you adjust the throttle stop screw or the two screws that hold the TPS in place?

If it was just the two screws that hold the TPS in place you can always just follow the procedure I linked to in order to adjust the idle switch properly.

Legacy777 wrote:Did you adjust the throttle stop screw or the two screws that hold the TPS in place?

If it was just the two screws that hold the TPS in place you can always just follow the procedure I linked to in order to adjust the idle switch properly.

Just the two screws that hold the TPS in place, I was too scared to mess with any of the other screws on it.

Ok, then yeah you can just follow the instructions to adjust the TPS idle switch per the instructions I posted. See how things work after you properly adjust the idle switch. Reset the ECU once you've adjusted the TPS.