94 zr1 missing @ start up (help!!!!)
 

My 94 mis-fires at start up. When warm the problem goes away. I do have a 02 sensor code. However, the system is open loop when the motor is cold. Thus I do not belive that this is the problem. Also, at start up, its running a little rich. I was thinking that leaky injectors could be the problem, but, the same problem exists if I park the car for a week. I'am thinking that this is ample time for the fuel to evaporate from the cylinder. Therfore, I do not believe that a leaky injector is the problem. Any ideas?

Thanks
Jeff

Re: 94 zr1 missing @ start up (help!!!!)
 

First, hello and welcome to the forum Jeff.

I'm not sure what is going on exactly, but on the injector front, don't assume that all injectors leak the same way. For lack of a better way of putting it, they can just leak a little, to filling up the cylinder with fuel which is what recently happened to me.

:cheers:

Re: 94 zr1 missing @ start up (help!!!!)
 

could be a cracked insulator on a plug. or a bad coil pack. check the spark by pulling a plug wire while running and use a spare spark plug, grounded against the plenum good luck!!

REPLACED COILS, AND PLUGS AND PLUG WIRES ARE IN GOOD SHAPE.
ANY OTHER IDEAS?

Describe the mis-fires at start up for us. Would you describe it as a backfire possibly?

This probably is not the only issue if a problem at all, but have you checked the map sensor hose to make sure it has not blown off?

The map was the first thing that I checked. I was wondering if a temp. sensor could cause these problems at start up. Has anyone experienced any problems with a faulty temp sensor?