bad fuel regulator?
 

Does a bad fuel regulator cause the engine to have a rough idle? It feels like the injectors are clogged when starting up. So the car would have a hard start. And when started up, the car would have a rough low idle. Feels like the engine would just die. I already changed the fuel pump, fuel filter, and even added some of those fuel injector cleaners in the gas tank and the problem still presist.

Re: bad fuel regulator?
 

Are you throwing any codes, is the engine light on? Have you checked to see if you are running either lean or rich? You can pull a the plugs to check. A rough idle can be a number of things. Also what do you mean by rough idle? Is the idle going from 1000-2000rpm, is it going from 1000-500rpm? What car, engine, any mods, help us out a little.

Re: bad fuel regulator?
 

no its not a "bouncing" idle. its just feels like the injectors are clogged and the idle is extremely low. like 400rpm. completely stock d16z6 engine. no mods

Re: bad fuel regulator?
 

ive got a wild idea. how about cleaning the injectors?

see general discussion for the HMT method.