after we swapped a sigle can vtec motor in my dx i began having idleing problems. when i'm at a stop light my idle goes really low and sometimes it even dies. its embarassing because sometimes i have to keep my foot on the gas just to keep the car from dying. my timing is correct and my plugs and wires are all fine, i do have a connector on the back of the throttle body that nothing is connected to. wat might the problem be?

 

does it stay running by itself when the car is cold? Or both warm and cold?

It could be that your IAC is unplugged, since you said a plug isn't plugged in. I would check that.

If that IS plugged in and your car only dies when it's warm, it could be the idle adjuster screw on the throttle body. It's facing the pasenger side and is just a flat head screw. When your car has a low idle, turn and adjust to raise/lower the idle.

Or it could be a vac leak

 

i was afraid it might be a blown head gasket

 

no, blown head gasket will lead to over-heating of your car, and white smoke from your exhaust

 

what exactly is IAC plug, i had a friend, who said look.

If i take this plug off your car, while its running and it shuts off than there is somthing wrong with it, and if the doesn't shut off than its fine, he did and needles to say the car died.

than he demostrated on his b16 crx, and showed that his car doesn't die when he takes that IAC plug out while the car is running.

What exactly is that ???

 

i searched everywhere no the throttle body for where to plug it can find any place. on my other throttle body the place where to plug it is there but on the throttle body that came with the motor its not there. they're different.

 

Well when you unplug the IAC valve harness it shouldn't die, it should should just idle really low because that is the base idle and is supposed to be somewhere around 500rpm? (maybe a little off on that one) I believe.

For those who don't know, the IAC valve is on the back of the intake manifold and has a wiring harness going to it. To adjust the idle, you unplug that and adjust idle screw to what it needs to be and then plug it back in.
If I have missed a step, someone correct me, this is how I've done it before.

 

oohh check your grounds!!!!!

I am willing to bet that when you did your swap you did not properly ground your harness, or your block, or where your starter is. Please check this, i hate to see you change all kids of stuff when all you needed to do is clean a grounding point.

check where the thermostat housing, make sure the 10mm is tight at the harness.

 

another thing could be the valves needing adjustment. If they are too tight, the car will want to die at idle because its not getting enough airflow.