ok so the random multiple misfire has been eliminated for the time being. We put my old crank sensor in the "new" engine, (after changing the ignition switch back to my original with no luck) she has more power now (not as much as i would like her to have, but more than what she did have), doesn't misfire until 4000 rpm on the dot. i slowly take the throttle up and right on 4 she kicks back about 500. the blinking check engine light does not come back on (before it did) and my exhaust no longer smells like it did before. anyone have any ideas as to what would cause this?
P.S> plugs, wires, air filter, fuel filter, coil packs are all brand new.

 

Your cat isn't clogged is it? Sounds like the park rev limiter is enabled when in drive....

 

Turbo is right, it could be a clogged cat or a bad Cam Positioning Sensor. I would also have the Ignition module checked.

 

Crank sensor relearn? Frayed/Loose wires at crank or cam sensor? Backpressure forcing spent gases into intake through EGR passage? Vacuum leak somewhere? Adequate fuel pressure? It sounds like the engine is going into 'protection mode' to prevent it from leaning out.

Double check the crank sensor wiring. It has to be routed a certain way or it is very easy to crimp the wiring and short it out.

 

the clogged cat is still a possibility, but we have replaced the ignition module and that made no difference. it also misses in reverse. i took it for a longer run yesterday and she miss fired at all speeds again. we replaced the crank sensor on the back of the motor and the miss fire at 4000rpm was the only thing it did after revving it and taking it for a cpl mile run so i thought that it was fixed (cold engine run, not hot till i got back) How do i do a crank relearn? i was told to have the dealership reprogram my computer, but i read somewhere else that someone did that and it didn't help. we have done a compression test and all cylinders were the same, we sprayed it down to check for vacuum leaks and found none (i was really hoping it was that simple) what gets me is that every time we change a part, it runs better for a bit and then progresses to worse the longer it is driven, back to the same old miss fire in idle and speed and loss of power which then trips the blinking engine light. my engine light does not ever stay on to bring up any codes set that would indicate a problem with one sensor being the problem so i dont even know where to start. the codes so far just from the blinking light have been miss fire at 3, then it changed to miss fire at 2, then it changed to random multiple. changing the crank sensor so far was the best help, i actually got some power back and she ran better aside form the miss fire at 4rpm and in reverse....then after a half hour drive that ruined all hope we were going in the right direction. we never hear any arcing, but im not ruling out spark just yet. all wires seem to be free and clear from damage. oh and ill add in that when i was revving it i had my hubby stick a paper at the end of tailpipe to see if when it miss fired it would suck the paper in and it did not.( i read somewhere that doing that would indicate something...but i couldnt remember what exactly it was)

 

Check the cat. At night after driving if the cat is really clogged it will glow from being so hot.

Don't rule out a pcm issue either. I had an electrical gremlin in turbo monte and it ended up being the pcm itself.

A case learn has to be done with actual pcm tuning software (hp tuners, dhp) if you don't have this a dealer or someone that has this tuning software would have to do it.

 

Last spring I discovered that my PCM had a Cadillac V8 program in it causing all types of intermittent sensor problems. I took it to the dealer. The Reprogramed it with an Updated program for the 02 Monte SS. I've not had a problem, PCM wise, since. Cost: $118.00
I'm saying the same thing as Turbo. Don't Rule out a possible problem with your PCM. Check your cat. If it is clogged it will cause miss fires because the exhaust gasses can not get out of the cylinders.if your PCM isn't reading the signals from the crank and cam sensors correctly it will cause random miss fires.

 

looks like im going to have it taken to the dealer. i dont think the cat is the problem because it will miss fire upon start up and the cat doesnt have enough time to even get warm?Theres just too many things that could be the issue, im tired of trying to pinpoint the problem, its been giving me issues for 2 months now. part after part after part, i can only handle so much before i threaten to drive them off cliffs .....if she wasnt so damn pretty sitting in my driveway taunting me.....

 

if a cat is clogged it is clogged no matter being hot or cold so yes it could be clogged while cold causing the issue. all i was saying is once its warm and driving a bit preferably up a hill so there is some load on the engine gurry up and look under the car to see if its glowing. if its glowing that means exhaust gasses are backing up and not flowing through so its getting hot and the car cant "exhale" so its choking aka missing..... just a thought this may not be the issue but worth checking out.

 

your local to me i just seen. drive down here and i will look under the car and see if its glowing. i also have compression and leak down testers we could try diagnosing it more if you want. if it can make it here.