I bought an 86 trans am with a 350 swapped into it and the 9th injector has been deleted. I had a chip custom tuned for the car and even with the chip I struggle to get the car started when the engine is cold. Can anybody tell me why people do the 9th injector delete? Is there a benefit from it? I really want this car to be easy to start in the morning. Besides that, it drives great with the new chip and feels powerful.

Reasons for CSI/9th injector delete... the switch broke. the fuel line got damaged. the injector isn't working. the wiring got hacked. it's leaking. You want to tidy up the engine. You are upgrading the ECM/chip and will handle the cold start enrichment through the main injectors.

Benefit... if stock is working, why "fix it" to make a problem? It could have economy/emissions benefit, but I don't recall conclusions about that.

Did you tell your chip tuner about the CSI delete? Did they program for that, or assume the CSI is still there? How radical is the engine?... Does it need more cold enrichment than stock?

Thanks a lot! And yes I did tell the tuner about the injector delete. I also gave him the cam specs and told him that it's a 350 as opposed to a 305. He said that the chip would need to be tuned for the injector delete, the cam, and the 350's 22lb injectors