Rough Idle Problem
 

Hi Guys & Gals,

I'm having a problem with a 1980 Non Turbo zx. I started off having a idle speed problem, it was idling way to fast after warmup around 1300 rpm, I started by changing all the vacuum hoses under the hood, replaced the air regulator, set the timing & TPS to spec according to the FSM. That didn't take care of the problem. Next after some additional trouble shooting I determined that the BCDD that is mounted to the lower portion of the throttle body was defective. I was lucky enough to find a new old stock OEM throttle body and installed it, and the fast idle problem went away. Now however I"m having a problem with rough idling. The car is hard starting in the morning but runs ok once it warms up. I suspected the fuel pump might not be delivering fuel to the system at the right pressure, and I can't here the fuel pump activate when I turn the key to the "ON" position like on all my other ZX's I'm a little confused about the fuel pump...... since it's electrical I thought that if the pump is not energizing that the car would not start at all? I am planning on putting 12 volts directly to the pump at the connector to see if I can here the pump running to determine if there is a problem in the electrical circuit or if it is the pump itself. Any other suggestions?

Have you already checked the fuel pressure? Fuel pressure regulator? Cold start valve?

Rough Idle Problem
 

The cold start valve is operating fine, I don't have a fuel pressure gauge so I guess I will have to either borrow one or buy one. How do you test the pressure regulator? with a vacuum gauge? and what about the fuel pump
not energizing with the key in the "ON" Position? I have 3 other zx's and I can
here the fuel pump activate when I turn the key.

I appreciate your response.

Thanks,

Phil