Jerrdog

Hello I have a 1986 z51 it's starting to have a hard starting problem in the morning,I try starting it without giving her any gas,but after it won't fire up I give it some gas and she will fire up but I can see some smoke from tail pipe for a few seconds. Not: sure how old plugs,wires and cap are? Should I do a tune up first? Any suggestions?

vetteoz

If it starts by " giving it gas " then engine is rich , which could account for the exh smoke
Opening the throttle while cranking the engine over shuts off the fuel because the computer thinks you are trying
to clear a flooded engine
I would be checking your fuel system 1st ; old injectors leaking fuel into the engine when standing maybe?

FWIW ,
you can't give a EFI engine gas ;there is no accelerator pump like on a carb to squirt the extra fuel in.
Opening the throttle while cranking lets in extra air = leaner

bjankuski

Not entirely true, up to 75% throttle it is increasing the pulse width with a multiplication table (You need to study the table to know what the factor is). At 80% it goes into clear flood mod and turns off the injectors.