Dead Cold Start Injector?
 

I have the 9th injector on my 87 GTA, and it has always fired up within 1 second of turning the key, then dropped to a steady idle.

Lately, it has fired off, stumbled and died, on a cold engine. Unless I blip the throttle.

It seems as if the cold start injector isn't doing its start job, as the only time it does that, is on cold starts. Once it has run, if I kill it & try to restart? It'll fire right off & drop to a smooth idle.

Could the cold start injector have gone bad somehow? Clogged? Dead signal? Fried?

Re: Dead Cold Start Injector?
 

Possibly, it's a fuel injector just like the other 8. I'd try ohming it first, that might tell you if something's gone wrong with the coil in it.

Re: Dead Cold Start Injector?
 

FYI - the cold start injector should be 4 ohms.

Re: Dead Cold Start Injector?
 

check the thermo switch that controls the ninth injector