90 Miata Hesitation/Misfire
 

Hey guys,

I have a 1990 Miata that has a terrible hesitation at around 3k RPM until about 4k where it finally settles down. This happens under both light throttle and WOT, cold or hot motor. The RPM's also tend to fluctuate at idle. CEL comes on at 3k RPM and usually when it misfires as well. When I checked the CEL, the only code that I received was 26 Solenoid Valve (Evap Canister Purge). You can check out a video of this problem here:
Mods, as far as I know, include:

Turbo (obviously)
COP Setup
Charcoal Canister Delete
New Injector seals and Insulators

I've recently smoked the vac lines and did not find a single leak anywhere. I used a spark tester to test the spark at each plug and all seemed okay. Only thing that I can think of is a fuel issue.

Is there anyone that may have any idea as to what's going on here? I'm trying to get this figured out before the snow hits and was wondering if anyone had any clue as to what this hesitation/misfire may be.

Thanks!

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