i have a 1987 iroc z 305 tpi. it won't crank when cold (overnight). the only way to crank it is to hold down the accelerator 1/4 to a 1/2 inch and it takes several times to get it cranked. no computer codes are coming up.
cold start valve or cold start switch maybe??
any suggestions on how to check or solve this would be greatly appreciated. thanks!

two things to check. cold start injector.
And if that dosent do it then you probably have a injector(s) leaking down.

what about the IAC? its a valve that opens at start up to let air by because the throttle plate is closed.its also used if you have A/C when the motor senses the drag it opens up a little more. with you depressing the throttle a little your letting air by. hope this helps.

This is typical of low fuel pressure. You will likely need to replace the pump. Ray