Hey guys, wanted to know what you think may be the issue that is cropping up here.

I was at the autocross today and there were several areas where it wasn't worth the time to shift up to 3rd so I left it in 2nd gear and rode the rev limiter for a moment.

The two time I did this, when I got back on the throttle to accelerate out of the corner, the engine would stumble - almost like I only have 3 cylinders, and power was very low. It would do this for a short second, maybe two seconds, and then smooth out and go back to normal.

I have video of it, you can hear the stumbe when I get back on the gas at 0:17 and 0:40.

My thoughts are that my red line cut out is on the wrong setting and so when i'm bouncing off the rev limiter I'm maybe flooding the cylinder with gas, but I don't really know.

Video:
Engine stumble after rev limiter - YouTube

-Ryan

 

I'm thinking fouled plugs you had to clear out. What kind of rev limiter do you have, spark only?

 

I can't say 100% off the top of my head, I'll have to plug in tomorrow and check. I want to say it's spark only. So you're thinking it cuts only spark and therefore dumps fuel which foul the plugs?
-Ryan

 

Makes sense to me.

 

I had the exact same issue as you when at the local drag strip, launching in first gear then hitting rev limit for a second or so , getting back on the throttle in second gear had the exact same symptoms (felt like half the motor went on coffee break), split second later back to normal.

Solution : spark and fuel cut

No more stumble