ChrisD

I'm getting a little bit of misfiring at 6-7k rpms but only if I lay off the throttle (usually it'll be in the races as I get ready to punch it, rolling next to someone). It sounds like a sputtering and the car lurches around a bit.. Unless I'm going full throttle it's very hard to sit around those rpms. The turbo shouldn't be spooled up since I'm not really on the throttle so I'm thinking it might be a fuel (too rich) or spark plug issue. Anyone have any ideas? I'm gonna call speedcraft tomorrow and see if they can shed any light on the issue.

cd

HITN9K

Sounds like you've got it nailed. Check your plugs or just replace them with 10-11 heat range plugs (colder burning). I'm sure Speedcraft would be able to tell you which ones will work the best for forced induction. Normally I recommend only NGK BCPR7ES-11, gapped at aroung .29. If that is not it, try removing 1-3 points of fuel on the V-AFC High throttle High VTEC setting. BE SURE TO WATCH EGT. 1-3 points to the neg should not be enough to run you lean but always watch you gauges. More than likely it is breaking up due to unburned fuel.

Summer

You also might want to do a search on the MAP sensor. This sounds vaguely like the problems being experienced by those who have had the MAP sensor problem. Having the sensor replaced has eliminated the problem in many instances.

S-

cjb80

I think you can be certain that the problem is fuel tuning not spark plugs.. If it only happens at a certain RPM and a certain throttle position it's definetly fuel, what you can do is go to a shop that has an air fuel ratio sensor and hook it up to your exhaust and duplicate it and you will see the sensor jump ethier lean or rich, then you can adjust the VAFC to compensate..

Chris

XXXRacing

I would say this is fuel related also...Most likely too rich...could be too lean too. I would play with your vafc and add fuel at that rpm first at light load and then if it gets worse, go the other way and subtract some fuel. Is always better to be rich than lean.