I think my 3sfe is mis-firing. Options

[MiSillyCar]

Hey guys, when im at 3000rpm in 2nd and 3rd gear. my car likes to jolt.. meaning slow down and then speed up within 1-2seconds.. what could this be? i got new spark plugs a couple of months ago. could it be o2 sensor? or Dizzy??
Cheers

[Xander_X]

I've had similar issues with both one of my Integras and my Legacy Sport. Is this usually happening when it is raining or at least damp out? Even if it's not, check all your ignition connections. Both times for me it was the coil pack shorting to the chassis before it could get to the plugs and it REALLY liked to do it when there was moisture in the air as it added a conduit for the electrical short. I had a pin hole in my MSD external coil pack on the Integra, the Subaru has a stock 4 post individual coil pack but one post was bad. So check the coil pack, look for any little (and I mean LITTLE) burn spots on it. Check your dizzy cap, check for green corrosion inside on the rotor and all the contacts inside the cap. Check plug gap, check ALL over all 8 boots of your plug wires for burn marks as sometimes you get a pin hole in them too. You gotta remember electricity will travel the shortest distance it can find to a ground.

I've found the best method is to start the car, get under the hood and rev the throttle to the point it usually does it and look at your components. That's how I found the little pinhole in my MSD coil, I saw it arc to the firewall. Or if you feel it HAS to be in gear, put the front on stands, have someone get in and recreate it while you look around the engine bay. I've had to do that too.

This post has been edited by Xander_X: May 3, 2012 - 12:30 PM