1994 Miata 1.8L, BEGI S3 Turbo kit. exhintake mod on a BP4W head.
Tune: Fine, Running Fine, no stumbling, no problems.
Gave it a good romp going through Milton Keynes (UK) on a straight.
Afterwards, hit accelerator, engine dies.
Starts normal, idles normal. But under load, stumbles for 1 second before everything kicks in.
Offset the stumble issue by no-load tapping on the accelerator to get the RPM's up, but the stumble is still there.
Problem dissipates at higher RPM's. It's still there, but seems to recover from the stumble much more quickly. Once it's up to speed, it does what it's supposed to do (come on boost, doesn't lean out, etc...) Just shifting and hitting the pedal from idle.
Connected Laptop to test TPS for a flat spot, re-cal'd it, and checked the gauges in Tunerstudio. Goes up smooth, no issues. (With engine off)
So, pulled a log. Not a super long one, and not under load (I can get it to stumble at idle in the same way.)
Tried disconnecting the TPS entirely, tried tapping on it, wiggling it, etc...
Should note that it did this one time previous, on Christmas Eve, and fixed itself before I could get home to get a laptop on it...