Mid rpm full throttle hesitation
 

Hi, I recently acquired my 7th/11th miata. A 97m with an FM turbo kit and a link ems. It was running fine at full throttle (not so great during normal driving) when I got it but had a few boost leaks. Now that I've finally fixed all of the boost leaks it drives incredibly smooth during normal driving but has a terrible hesitation along with the check engine light turning on then back off, Midway through the rpm range (5-6.5k) at full throttle. After turning the boost down to wastegate level the check engine light no longer comes on but the hesitation is still there. according to my aem wideband, the AFRs stay right at 10.0 during the hesitation which I know is a little bit rich but I wouldn't think it would be rich enough to cause the issue I'm having. I've tried replacing the plugs and wires with a brand new set of ngk bkr7e and blue ngk wires and the problem still persists. I also have tried going back to the default settings on the link and going through the steps in the manual to get it to where the autotune feature takes over only to get the same problem.


Any suggestions would be greatly appreciated!

The Link turns on the CEL when it detects knock. It also backs the timing off when this happens. So... it's detecting knock. Or it thinks it is.

It might be something as simple as a loose knock sensor. They're mounted near the oil filter and have a sorta coax wire if I remember right.

The AEM WBO2 bottoms out at 10.0:1. The air/fuel ratio could be 8.0:1 and the WBO2 would still show 10.0:1 because that is as low as the gauge can show.
Have you verified the Link ECU is set up for the input from the AEM WBO2 senosr? On the keypad is a screen that shows O2=. When set up for a WBO2 sensor that screen will show WBO2=.
Does the WBO2 sensor read around 14.7:1 when cruising? Does it display richer values when you accelerate at less than full throttle?
Did you check the ignition advance in the cells in which you feel the misfires?

Sorry for the delay but I figured out my issue the day after I posted this. I have 610cc injectors and didn't realize that the fm kits only come with 550cc injectors. After some adjustments it runs great now.

Thanks!