My car misfires when it's cold started, to the point that I can't drive the car until it's run for a few minutes and has a hard time idling. This happens when it's like 45 degrees or colder outside. When this happens I get an SES light, low res pulse circuit grounded. It's obvious in the exhaust that it's dropping cylinders, you can hear it clear as day. After it warms up it's fine. I'm running a delteq so I was thinking it was the cam position sensor in the opti since I used to get low res pulse circuit open codes... weird thing is, sometimes if I go over a bump the SES will flash for a split second and I do mean the blink of an eye, or when I'm taking off from a light it will stumble HARD, the light will come on, then it clears up when I drive it for a minute. So I'm not sure if it's a sensor or a loose wire somewhere. Anyone have experience with this?

Car is a '94 382ci. with the vented opti and a delteq, no spark box.

 

It would appear that you have an intermittent short to ground on the red/black wire from the opti. But what is weird is you don't have the problem after it warms up. That is, until you go over a bump or something. Why don't you unplug the harness going to the opti and check the red/black wire to ground with an ohm meter while everything is cold and wiggle the wire every where can. Be sure both ends are disconnected when you do this.

If you don't see anything there, try ohming it from opti end to PCM end and wiggle it all over again. It's on the black connector at the PCM.