Some background to start.

This is a tubeframe 2009 MX-5 with a streetport 12A. MSII firmware 2.687, 51mm throttlebody with 4 - 2nd gen injectors with a 27MM SIR (single inlet restrictor).

On a quick upshift, 2nd to 3rd etc, as I go back to full throttle I get nothing. If I pump it a few times it comes back and the wide band shows 21.0 during this. If I roll into the throttle slowly it's ok, not optimum for racing.

Never had this issue with the other car, Suzuki Swift 1300 DOHC.

What do I need to look at?

Thanks
Jon

 

One other thing. At first I thought it might be the SIR, but I had a Weber 48 IDA and it never did this so I don't think it's an SIR issue.

 

Any particular reason you're using the standard code? Not running igniton or staged injection?

Generally when that happens it's because of accel enrich or the bottom of the table isn't tuned, or the opening time is wrong.

Ken

 

A log would be great.

Are you running speed density or alpha-N fueling algos? As Ken said, the first thing I'd look at is your AE settings. I've used mapdot on many rotary installs, and all but two of them worked very poorly. IMO TPSdot is the way to go. Start lean, and work your way up in AE values until the engine becomes responsive and crisp. I'd recommend setting two gauges up in MT: spark advance and duty cycle - you should see both jump up rapidly upon throttle jab.

Also what is possible is that your overrun or low-load VE values are low, so when you come back on throttle you need to re-wet the walls. Rotaries like to be nice and saturated with fuel during tip-in to avoid leanness.

 

I must mention that MAPdot is tougher to dial in but, in my experience, is very workable. I'm not sure where MAPdot was mentioned in this thread - did someone edit a post?