1986 Pontiac Trans Am 305 TPI, bone stock with the exception of hooker headers. I was told my cold start injector and fuel injectors are faulty. They are original to the car. What is the proper way to test the injectors, and csi? Where can I buy a new CSI? Can I just buy a 9th. 19lb. injector for it? Also do I need to remove the runners as well as the plenum? I am also considering an adjustable fuel pressure regulator.... and recommendations?

 

Is the 9th injector only in the 86 car do it takes a while 2 start after sitting do it miss fire do u have a code up I think u can pull the injectors if u unbolt the fuelrail

 

85-88 TPI engines I believe. I have one on my 88.

I understand its possible to just block it off and recalibrate the ECM for the lack of the 9th injector.

It is indeed a separate part though. Not the same as the other 8.

 

I recommend removing the CSI altogether (via a block off kit) and either having a custom prom burned or find one from an '89 TPI with the same size motor. That's what I did, plus replace the old injectors with Bosch III's.

I tested my injectors by unbolting the fuel rail and lifting it (and the injectors) up just enough to place some clean paper towels under the injectors. Then pressurize the fuel rail and look for leaks from the injectors. You can do this with the CSI as well, if you carefully pivot the tube at the fuel rail.

You will have to remove the plenum and one set of runners to complete the above.

Hope this helps.