ok whenever i have my a/c on, or defrost, right around, 1700, 1800 rpm according to my tach, which would be 1500, 1600 rpm according to the computer, it kinda studders, just for a split second though, i can just feel it.

anyone got any idea what it could be?

 

help please?

 

Mine did this.
Replace stuff in this order till fixed:
1. Verify fuel pressure is in spec.
2. Replace plug wires with MSD 8.5mm super conductors. Make sure they DONT arc by spraying a fine water mist on them and the opti.
3. Replace plugs with AC Delco and gap to .050".
4. Inspect opti for loose rotor button or just replace it with GM only. The cap will start bleeding off spark with age.

 

i had a similar issue that i fixed by replacing the coil wire

 

Guessonosis is plug wires, especially if this 1500-1600 rpm is while driving in lockup or with a stick.

 

yea it only happens when driving, its like a studder, for a second then its fine.

 

Does it start doing it after the car reaches normal operating temperature? or is it like that all the time?

 

Pull out your plugs. Tell us what they look like.

 

are you sure it just isn't the compressor kicking in and out? Sometimes on my car i can feel it kick in and out while driving at low speed when there is very little load on the the motor

 

that would be my guess

 

tannish brown, they do have close to 70k on them though......


i know i need to change them, i just need to find time.

 

replaced the coil wire... it seems to have amplified the problem.


any new suggestions?

 

PLUG WIRES

 

any reason behind that, replacing the coil wire has nothing to do with the plug wires, nor do you get anywhere near them, not that i am ruling them out

i would check the wire harness connector at the coil and maybe make sure you have a good connection at both sides of the coil wire

 

As the wires age the electrical resistance will usually increase. This will cause the spark to seek the route of least resistance. If there are any cuts, kinks, cracks in the insulating material then the spark will jump to the closest piece of metal causing misfires. Any corrosion on the wire termials will cause a loss of spark energy too.

I had a low end stumble that I traced to the OEM wires. I removed them and installed the MSD 8.5mm super conductors and the stumble was totally gone.

The LT1 uses a very high energy ignition system, it requires the paths for spark transfer to be in excellent condition. It is even more critical that things be excellent condition when moisture is present from driving in rain. My old wires got wet from normal driving and I saw sparks shooting out of the rubber boots and going to ground. This is typically referred to as arcing. I could even hear the popping sound when this was happening.