Since the 3L install, I've had this problem but only at sustained RPM's above 3250 (e.g. freeway driving at about 80-90MPH). Only seems to happen once the car is warmed up and has been running for at least 10 minutes or so. Seems completely sporatic. No pattern at all to it. The only thing that is consistant about when this happens is that it happens above 3250RPM.

It's almost as if I'm hitting the rev limiter, thats the best way I can describe it. Car bucks twice, like two quick hickups right after each other, or as if you somehow hit your rev or speed limiter twice, then is fine for awhile. Sometimes. Sometimes it happens again right away, sometimes I can drive for a good 20 minutes before it happens again. Always 2 bucks, or hickups, and always over 3250 RPM.

I've replaced the fuel rail and injectors when I upgraded to 19# injectors, so I don't think its in the fuel delivery. Fuel filter is about 8 months old. Doesn't matter if I have a full or empty tank of gas.

I'm beginning to think maybe spark? Either plugs, wires, or the coil? Anyone else have any thoughts?

btw, seems to happen more often on warmer days for some reason

When something similar happened to me on my non-SVT 2.5L, it turned out to be the subpar plugs that I installed. I put in Autolites two years ago and haven't had any hiccups since.

Is your car chipped?

I had this exact thing happen with my superchip... it had come loose by an ever so slight margin.

-Lance

Why yes he does. Superchip too. I think Lance is onto something.

Yup, I have a chip. I've checked that though, got 'er taped in there real good. Maybe I should try re-cleaning those contacts maybe.

I've ran a superchip for a couple years now, and only now have had these problems. Odd. I'll keep everyone posted.

Sorry to restore an old thread, but for archival purposes:

This issue has been resolved. Once I went with a XCal2 and burned my tune directly to the PCM the problem dissappeared. Seems that my PCM wouldn't hold onto a plug-in style chip like SCT or SuperChips very well.

I have the same problem at lower rpms, and I do have a superchip.