i have 86 GXL manual, the previous owner had the emission eliminated, electric fan on radiator, everything else are stock, has 84k miles.
it idle up and down from 500 to 1500, once i unplug this white clip(shown in picture), it idles normal, which is 750 rpm, so i drive her with this clip unplug.
it drives normal, the only thing is, it will die on me while i have the A/C on and the water temp is higher than the normal temp, which the niddle points at the middle at water temp gage.
anyone know what cause my idle rough? i had been tried so many different solutions, such clean IACV, change the whole throttle body, checked vacuumm leak, no vacuum leak.
thanks for reading. and sorry about my english. :P

http://www.flickr.com/photos/23732694@N03/4561706961/

 

The plug you have disconnected belongs to the Air Bypass valve which is used for the 3000 rpm startup which lasts for 17 seconds so it's not really vital to have it hooked up. With regards to the car dieing out that would be related to the BAC. While cleaning it is good it still might not be performing up to spec. If you were to slow down the speed of the fan as you come to a complete stop does that help to prevent the car from stalling and does the car always stall with the A/C on whether the car is warmed up or not? If worst comes to worst you might want to bump up the idle a bit to see if this helps at all.

 

if it gets real hot outside and i have the a/c on, the water temp would slowly raise close to mid range of the temp gage. mean while if the car come to idle, it will drop to 2-300 rpm then engine dies on me, i notice if the water temp gets high, and i dont turn off the a/c, the engine is kinda like lack of power to run the compressor. once the engine shuts down, i have to turn a/c off and restart engine, drive it with a/c off, the temp will then slowly drop.
should i get a better radiator, something like toyo, and set the idle rmp higher, to like 8-850 rpm?

 

Running the A/C will result in the engine getting hotter as that is the trade off and not so sure that getting a different radiator will help to prevent the car from bogging down as it's basically a function of the BAC. Bumping up the idle might help. After driving the car and the car is turned off check the BAC to see if it is vibrating as it should. If it doesn't vibrate then it indicates that it is not working properly. Also if you could possibly idle the car with the A/C on where it doesn't kill the engine then pull the electrical plug from the BAC and see if the engine dies or practically stalls out or not as this would be another indication of the BAC is working. Lastly, maybe you need to flush the radiator properly and refill it in addition to replacing the thermostat as a precautionary reason.

 

My old engine started to overheat when i ran the A/C because it had a very tiny coolant seal leak. After 155k miles, the seals themselves where fine, but I had 3 cracks into the cooling jackets of the front iron. My A/C has freon in it, but is a bit low so I haven't ran it since I got my new engine, since I don't want to risk overheating. Brand new rad and thermostat.

I'd check for coolant abnormalities. Bubbles and air pockets are NOT good. A good running engine with the system free of air should not bubble or "plop" bubbles at all. At idle, with a funnel in the radiator caps place, should get hot enough to steam up a bit, but no perturbations should occur.

 

if i turn a/c on, idle stable at about 1500 rmp instead of rev up and down, i just remember that i had this tested couple months ago, not sure if still doing the same thing now, will check when i get home.

 

and this white clip does not directly connect to the IACV(part#N326), its wire leads down to the throttle chamber. BAV = IACV(part#N326)? cuz IACV(part#N326) has blue plug.

 

The Air Bypass solenoid is not the same thing as the Bypass Air Control solenoid. When looking at the throttle body from the driver's side the BAC is on the left and the Air Bypass is on the right. The plug you disconnected goes to the solenoid on the right.