I recently bought my 1986 rx7. The owner said it was cold natured. What he was meant is that when you start the engine cold it will keep dying untill it gets warm. The car idle's fine at 750 but only when the engine is warm. From what I have read my engine might just beed a new BAC valve. Any suggestions?

 

Maybe the thermowax was removed, is the aws hooked up?

 

sorry, I am a noob when it comes to this car since I just got it. Is the aws some kind of solenoid? and what is the thermowax? All I can say is the engine has been rebuilt and it drives fine. Just in the morning when its cold it doesnt want to idle.

 

One way t o tell. Fully warm the car up and let it idle. THEN while idling, pull the elect plug off the BAC.

The rpms should fall down some, but not a lot. IF it dies, then the bac is working for sure. IF the rpms drop down just a touch, it still a sign that it is working.

IF there is NO change in rpms when the plug is off, then I'd suspect there is no signal going to the BAC from the ECU or the pins inside the elect plug are pushed back and not making contact with the pins in the bacl itself.

So let's say there was a change in rpms meaning the bac is functional

Then I'd assume the water thermowax on the throttle body is not working or there is no water going to it. The thermowax should be cracking the throttle plates open a bit so the engine idles at approx 1300 rpm when cold, but as the water in the engine warms up the rpms should gradually come down to the seven fifty area.

The FUEL section of the FSM shows how to adjust the water thermowax. FUEL section. Free and online FSM available.

 

Yes check to see if there is a coolant line coming from the rear iron up to the back of the throttle body. If it was rebuilt it is a possibility the system was removed.

 

Thank you