Hi guys/gals,

lately I been having some sort of idling problem and I cant seem to figure it out.
First off when I started her up it sound weird, like I have a cam or some thing, she used to started up on the first key turn, but now she sits there for about 20 seconds before she starts, finally when she starts I sometimes get a cloud of smoke that smells like gas.

After she starts the idle will not go below 1500 while in park, then when I am driving she idles about 1000, I changed plugs with ac Delco plugs new wires and cap & roter, it almost sounds like my timing is off because she back fired once.

I have manually turned the idle screw all the way down but still get this insane idle, please help before I take her to the shop and get hit with a huge bill.

1987 Iroc-z28 5.7 ltr
no mods all stock.

 

Leaky injector maybe. You're going to need a fuel pressure gauge and a scanner to see what's going on.

 

Any codes?