swap problems

[clean3rdgen]

I just swapped in a JDM B20A and now I have a jumping idle. Any ideas to what is causing this?

[sofast]

I dropped my B20a in earlier this week. I fired it up with success yesterday. check it out

http://www.cardomain.com/memberpage/528935





Check all of your vacume hoses. Are you using the JDM intake manny? If so did you plug #16 vacume hose from the vacume box. #16 is supposed to go to the egr. Here are a few more other fixes

1. Air in the coolant lines -- there's a bleed screw near the temp sensors on the thermostat housing. a 12mm wrench will open it. Let the engine heat up and open that screw every few seconds until just solid coolant comes out.

2. Idle screw set too high -- if the idle is too high, the ECU will try to compensate by cutting the injectors. this causes the annoying bounce. Disconnect the 2P connector from the EACV. This will throw a check engine light and cause the engine to run funny. It should stabilize. Then adjust the idle screw until the warm idle is at or near 770. Turn the car off, reset the ecu, and reconnect the EACV.

3. Fast idle valve -- coolant flows into this valve and operates a wax ring. the wax ring contracts or expands with the temperature of the coolant. The operation of the wax ring gives you the increased idle when cold. If this wax ring is bad, or the valve is just old and loose, then too much air will "leak" into the intake manifold, causing another high idle situation. again, the ECU will try to compensate by cutting the injectors. This will continue causing the bouncing. if you've tried the other options, there's an easy test for the fast idle valve.

Take a ceral box, or anything made of the same kind of cardboard. cut a piece of the cardboard to fit between the FIV and the intake manifold. Place the cardboard piece between the FIV and the intake manifold and bolt the FIV back on. Let the engine heat up. If the bouncing goes away, then you know it's the FIV. If the bouncing is still there, then it's something else. Don't be afraid about the cardboard...I had that piece of cardboard in there for over 7 months with no problem. Was it smart to drive around with it in? no...but, it works as a test. Once you know what the problem is, take the cardboard out and put it all back together the way it was.