hey guys got my 2000 monte ss with 120k miles on her. shes been serviced and i always do early maintains on her and check my fluids daily ect. last thing i did to it was about 2 months ago now 1000 miles ago, i got zzp 10.5mm wires ngk colder plugs (recommended for sc applications) changed the oil with full synthetic mobile one 10w 30, stp filter, flushed my radiator, and got a new pod filter. yes my plugs were gapped correctly, yes i have all the right wire going to the right coils, yes they are all on checked today. anyways on my way to a carshow about 20 mins away or less, my car was acting up. i really dont know how to describe it. well first off if i go over 30 mph or so my car likes to pluseate? or act like its out of power kinda, and you can hear it in my exhaust sounds kinda like wampp wampp wammp then if i give it a tiny bit more gas its fine and it wont do it anymore. after than it was making like a popping noise kinda but you couldnt hear it in my exhaust but you could hear it under the hood sounds like a misfire and it will make the noise about 3-5 times then it will stop and wont do it. after all that bull****, ill be going around 60ish and if i let off the throttle my speedo jumps from like 60ish to 40ish sometimes even lower than that, then if i tap the gas again it will jump back up to my current speed. weird **** ive never seen anything like it. but its doing all the and it seams like it only happens when im on the highway, no check engine lights, no leaks, drips or anything like that fuild levels are good engine temp is good, oil pressure is good and i dont burn oil or coolant. SOMEONE HELP ME! only thing i havent done is take the plug out and check them.

 

Have your Coils checked. With a miss fire, if that is what is actually happening, you work back from the plugs, wires, Coils, ignition module. Could also be a bad Cam or Crank sensor.
Since you have no CEL, I recommend having a Live read, engine running. That will not only tell you if you have a miss fire, but it will also tell you which cylinder, cylinders have the problem. If a coil goes bad, you will ha e a miss fire on the 2 cylinders connected to it. Good Luck!

 

had a buddy of mine with a scan gauge 2 read my codes before i started dicking with it. code p0300(multiple/random misfires), so i swap the coil packs out with ones i know for a fact are good and have been tested. after i swaped them it seamed to idle better and you couldnt really hear the mis. got it read again and it threw the code p0306 (cyl 6 misfire). so its not the coil its not my wire. only thing i can think of is that my spark plug for cyl 6 is bad or its loose, or that the coil ignition module (what the coils sit on) is bad. can anyone tell me what else it could be other than that? anyone have the same problem or something close to it? open to any suggestions

 

Install acdelco plugs and see if it fixes the issue. Also idk how modded your are but if modded a decent amount I use auto lite 103 plugs. Regular copper core nothing fancy and they work great!

 

Double check your #6 plug wire making sure it is fully seated at the coil and the plug. While you have the wire off the coil, inspect the inside of the coil terminal looking for oxidation. Clean if needed. Have the resistance of the wire measured checking for excessive resistance versus the manufacturer's specs. Find a dark area and (with engine running) check for crossfire between wires. If you don't see any obvious crossfire, use a spray bottle and mist the wires while watching for crossfire. If they do crossfire, try rerouting your wires. Check the spark plug for proper gap. If all that checks out it may be your #6 injector. A quick way to check it is to swap it with one of the other injectors. If the misfire is now the cylinder you installed the suspect injector in you have found your problem - the injector. Before replacing the injector you may want to try running a high concentrate injector cleaner through the fuel system and see if that clears it up.

 

Just out of curiousity, what did you gap the plugs to?

 

to .60 i beleive

 

thought i had it all fixed. left work came home no problem. went to leave 5 mins later and it died in the middle of the street. pulled over and turned it off and then turned it back on, it would crank but woundlt turn over. but you could tell it was sparking. so i swaped the ignition module and that wasnt it. did the same thing if you tried to start it. so heres the problem some sort of misfire. its not the plug<wire<coil<module anyone know anything i can try. im kinda sol because shes my racekar and my daily driver. someone please help!!!!!

 

Did you already do the top swap, and if so who tuned the PCM?

 

i never did the swap, so im running a stock tune