78 280 idle mystery
Just finished a head job. Installed a msa header. Deleted egr.
Car started right away. Idled great at 1200, isles smooth at 850 once warmed up. Adjusted idle via screw to 800. All was good. Closed driver door. Car started idling rough and stalled. Wouldn’t restart without throttle application and would barely idle sometimes stalling.
Checked all vacuum hoses. Everything looks good. Car revs up but sounds like it’s misfiring. Checked valve clearance. All good. Car still idles rough.
Close door. Everything smooths out.
Open and close door. Car isles like **** again. Now I can’t get it to idle good again.
Another note. When idling good idle screen works as it should. When idling rough appears to make no change.
When I pull the pcv hose the idle increases but doesn’t smooth out.
I’m at a loss.
Also the car ran fine before the head was pulled. Failed manifold gasket necessitated head job. Nothing else on car was touched
78 280, possible black pearl