rough idle,low vaccum

[hcm1957]

I have a rebuilt 350 270 hp engine. Original quadra jet rebuilt and runs rough. Have low vaccum. Help

[maxwedge]

Wow pretty general. vacuum leaks obviously, valves too tight, timing wrong, for starters.

[danielsatur]

Do a smoke test to pinpoint any vacuum leaks.

[hcm1957]

Timing is on, Lifters are adjusted correctly and no vacuum leaks around intake.All vacuum lines are plugged. still have rough idle and can not adjust idle mixture screws

[maxwedge]

Compression test next. Or short out one wire at a time see if one cylinder does not change the engine speed or roughness.

[DeltaP]

My 2 cents: Faulty or incorrect PCV valve or hoses. Poor valve seating. Restricted idle passages. Bad coil. This is in addition to everything else mentioned.

[hcm1957]

Thanks for your 2 cents. All new hoses and pcv, heads where redone and running hei.