When I drive my car, right about 5700-5800 I get one hard jerk, like stumble. it is not the rev limiter, the rev limiter is set to 6400. What could this be? Car has new plugs, wires, msd digital 6 ignition. Perhaps bad coil?

 

I've got teh same prob and can't figure it out. I know i have alot of arching so when i get some time i'm gonna solve that prob and go from there.

I'd just start with the plugs, wires, filters, etc. and see where it leads ya.

 

i had the same problem, it was exactly as you described it. i put in an LT4 knock module and with 5 mins the problem was completly gone. hope this helps

 

Yea like I said, the car has new plugs and wires...The car also has an lt4 km. I wonder if it could be knock or false knock causing the computer to pull timing...I might want to scan it...

 

I have the same type of thing, but it's a series of light, annoying hesitation from about 5500-up. As far as I know my 120K mile car's Opti is original, so that may be it. I changed the wires with new factory ones and installed Bosch +4 plugs at 75K, but it's pretty recent my car started doing this. I posted a thread about this last nite and my 1 response was to replace my plugs because they are supposedly not that good with mileage, so I may try some NGK TR55's.

 

car also has new opti...

 

check to make sure the plug wires are all the way on the terminals at the opti. I had a similar problem which I described in a thread a few pages back and that is what it turned out to be. Luckily I already had a new opti waiting because the terminals were all corroded.

 

it could very well just be a arching issue, did you replace the coil wire?