Rough idle and engine hesitation

[NotSquidward]

So I recently bought a 93 300zx na 2+2 it starts up every time but idles at around a 1000 rpm and then rpms start to drop and it dies. If you try to drive it, it has almost no power under 3000 rpm at which it sometimes backfires and then takes off like a shot of nitrous. All the injectors have been checked and I checked the fuel pressure before and after the filter and after the damper all of which were between 42 and 46 psi when I checked ecu codes it gave me 55 which means no malfunction. I have no idea where to go from here someone please help.

[nissanfreak12]

Check to see if you have an intake or vac leaks.

Does the idle bounce at all?

[DCaff300ZX]

LOTS to check here for this issue, if you are DIY inclined the fsm has a lot of tests and such to help you nail this down. Find the fsm in the "everything you need...Z32" sticky on the top of the page.

[NotSquidward]

Sorry it took so long to respond but the idle does bounce slightly, on start up it starts idling around 1000 rpm and then drops while twit himg all the way down. I also think your right about an air leak because it sounds like it's not getting the right amount of air but I haven't checked for vacuum leaks yet

[Ace2cool]

That's basically step one of the process. If you're introducing unmetered air, you're gonna have a slew of issues and any further troubleshooting will be basically wasted.

[DCaff300ZX]

Sorry it took so long to respond but the idle does bounce slightly, on start up it starts idling around 1000 rpm and then drops while twit himg all the way down. I also think your right about an air leak because it sounds like it's not getting the right amount of air but I haven't checked for vacuum leaks yet

As Ace mentions, there are steps to the process in order to accurately find the problem or even not be completely wasting time, so be sure to use the fsm and it's tests to solve your issue...or be ready to waste lots and lots of time, get nowhere and be really, REALLY frustrated and maybe do something you shouldn't do...

[NotSquidward]

Sorry it took so long to respond but the idle does bounce slightly, on start up it starts idling around 1000 rpm and then drops while twit himg all the way down. I also think your right about an air leak because it sounds like it's not getting the right amount of air but I haven't checked for vacuum leaks yet

As Ace mentions, there are steps to the process in order to accurately find the problem or even not be completely wasting time, so be sure to use the fsm and it's tests to solve your issue...or be ready to waste lots and lots of time, get nowhere and be really, REALLY frustrated and maybe do something you shouldn't do...

Thanks for all the help I changed some vacuum lines and that seemed to do the trick. car is in decent running condition now