vacuum, intake, or timing?

[CaspersFoxes]

my car's running a little rough since the rebuild. it spits and sputters at around 4k and it idles rough once in a while, so rough some times that it kills itself

 

[408WBlackCoupe]

Check all Vacuum lines and spray around the intake to check for leaks. Doesn't sound like timing to me.

 

[CaspersFoxes]

will do, appreciate it!

 

[HISSIN50]

You don't happen to have platinum plugs do you? On some cars, they can cause a low/rough idle and cutout at 3500-4K RPM.

 

[TokyoJoe]

Carb or EFI?

4k sputter sounds ignition related. Plugs, wires, cap all in good condition?

 

[CaspersFoxes]

actually i do have platinums, and its efi, i got a new cap and rotor and accel wires

 

[CaspersFoxes]

You don't happen to have platinum plugs do you? On some cars, they can cause a low/rough idle and cutout at 3500-4K RPM.

is there a plug you recommend?

 

[Mustang5L5]

Stock oem copper motor craft plugs