Just finishing up on a lsx swap in my 86 c10. I got everything hooked up and engine started, but it will only run a couple of secs and goes dead. Starts right up but dies after a few secs. Thought it could be a fuel pressure issue so I checked it and it came out good. I have narrowed it down to the fact that the injectors quit firing because if I spray starting fluid in the intake it will keep running. Could this be the vats system killing it? I ran the codes on the computer and it says that the computer came from an ls1 car. I took the computer of of a 5.3 truck though so I figured that it must have been tuned for the truck engine and that vats was probably turned off. Maybe I was wrong. What do you guys think?

 

Doesn't matter what the PCM is out of, the VATS needs to be turned off.

 

Yeah I know. Just figured that being that it wasn't in the original vehicle then someone may have already turned it off. Guess not. Thanks

 

Sounds like you need to do a security relearn/crank relearn.

http://www.nelsonperformance.com/passkey.htm

 

That won't help at all since his 86 truck doesn't have a BCM or key sensor. He needs VATS turned completely off for it to ever work.

 

Yup. Factory theft deterrent kills the injectors.

 

Whops I just skimmed the post and thought it said he swapped PCMs. I didn't know about the components of the VATS though, but a quick google search filled me in