Ah, limp mode?
My Z goes into something like limp mode randomly (only after startup). It will rev, but very, very slowly - making it near impossible to drive to work. Sometimes a quick shutoff and restart after a minute will get it back going to normal. Sometimes it takes like 10 minutes (which I obviously can't do in traffic). Frustrating, but no error codes or lights... which is what's strange about it.
And I don't redline it like you.
