63 Pontiac won't start when cold



1963 pontiac grand am, quad four fuel injected won’t start when cold. Will only start when starter fluid is used in breather. AFter engine gets hot it will start over and over again. Have replaced all electrical sensors and switches and the computer . Checked injectors for problems and about to GO BALISTIC. GOT ANY IDEAS???

Trying to help my neighbor who has been working on this for three weeks and he is a pritty good mechanic with 10+years auto experiences. THIS HAS US BAFFLED >>> HELP

The neighbor , Bill


They had choke and carb systems in 63 and no Grand Ams. If it is an 83 or something, first thing I’d look at after checking for fuel pressure and spark is the engine temperature sensor. If that is bad or the connection or wiring bad, it’ll crank and crank and crank before starting.

If it really is a 63, then suspect a leaky carb bowl, or inoperative choke.


the first step is to see if you are missing fuel or spark. You can’t tell using starting fluid since it will ignite just from the compression of the engine.

Try a cold start with gumout carb cleaner instead. If the engine starts, it is a fuel problem. If no start, it is an ignition problem.