i purchased a 78 monte carlo Vday.
runs great like a champ when i can get it to stay on.
only thing it needed was valve cover gaskets.

so i replaced the gaskets and now
when i turn the key it wont stay crunk more than 3 seconds

what could this be?

if i apply carb cleaner it will crank and seem to idle proper. (drove it yesterday no problems.)
but if i let it sit overnight it struggles to start and when it does,
its only for a couple Mississippi's

note that ive changed all vac lines, fuel pump, & filter.

my mech thinks its a ICM problem. any ideas?

 

anyone?

 

Have you checked the easy stuff yet like the battery/alternator/starter, and plugs and wires? Also, how's the compression on each cylinder?

 

EGR valve, or just maybe the dang valve on top of the valve cover. The correct word escapes me, maybe the hose running to it from the carb got knocked loose?

Mike