Without a code could be fuel ..or spark related . Could clean the maf will cause your symptoms if dirty..and air plenum from air filter to throttle body is not sealed up air tight. The maf reads air flow any unmeterd air will cause problems ..get maf cleaner at auto parts..take maf off spray good..let dry..do not touch the filaments on the maf. just spray good. You know now to disconnect the battery first?? This will be a good place to start without a code.
Oh if it was the regulator you would get long start times..then no start. You have to replace whole spyder injector on your to replace regulator..cheaper.
The reg. connected to the spyder no vacuum line ..gets vacuum from sealed system under the intake. Seems this will be your problem did not start till you messed with stuff.