LS1 Swap Car dosn't Start
 

I am putting a LS1 in a 2000 V6 firebird and the car will not start. I put a 99 computer, harness and gauge cluster along with a new fuel pump. I removed the EGR valve air injection and the rear oxygen sensors. I added long tube headers. The car has the air pump and the service vehicle lights on (not the service engine soon light). The car will hit but will not run can anyone help?

start with the most obvious and recheck all your electrical connections.

everything seems to be hooked up

And...
 

In with the above, add checking the key circuit. If the engine will 'hit", but not run, look to see that the run and start sides of the key are hot. You may have "fire" in crank, and when the key is released, there's no power.

Won't start
 

Like mentioned earlier, check the basics. Need a few new tools to work on a modern engine. First is the noid light to see if the injectors are working properly. Next, use a timing light to see if the plugs are getting fire. Use a pressure gauge to see if you have fuel pressure at the rail. If you have these then it's trouble shooting time. Did the engine sit long? If so maybe the injectors are clogged. Did you have the VATS programmed out?

Great advice! ^^^ I actually had the same thing happen on my swap, 10 minute fix.......

OK what is the proper way to check the key switch? Ok let me add I sent the computer out for a mail order tune deleted the VATS EGR & Air. When I try to start it I get 3 or 4 loud pops out of the exhaust, different now than before I sent the computer off. I also have 80psi fuel pressure? I am old school if it gets fire and fuel it will run this modern stuff has me going back to school, can anyone help

80psi sounds sky high, will injectors fire with pressure that high static? Will it fire with starter fluid?

I haven't tried starting fluid but I think the pressure is my issue it should only have 56 psi. I am looking for my problem

I am back to working on my swap still can not get it to run checked injectors and fire everything is working checked all grounds even tried another computer it sounds like the motor is out of time Put a scanner on it in live time while it shows the timing advancing and retarding up to 25 degrees so I pulled the front off the motor to check the timing chain and it dose have about 3/8" slack in the chain could this cause my problem I am not convinced this is my trouble ? anyone have any suggestions

1) key on - do you hear fuel pump prime for 2-3 seconds?
2) key on do you have 12 v at coils and all injectors?
3) what map sensor are you running? What map sensor in tune they need to match.
4). All grounds on back of head? There are 3 in a normal harness, also ground strap from. Block to chassis required.

If you have all of above it will fire for sure

Also can you hook up any scanner to obd2 port and see pcm is powered on w key on

The fuel pump is running coils and injectors are working (not sure what voltage they have) map sensor is right I know there are 2 grounds on the back will check for the third one and I do have the chassis ground. Any thoughts on the timing chain

you sure you have full 12V on all the power sources? if you tapped into firebird wiring, make sure it's a full 12V with on vs. 5V. I would tie all the pinks to the battery positive via fuse and try to start it to eliminate it as a problem.

I used an OEM harness so everything is stock but I will try that tonight

c100-101-105 from the stock harness you are using, I don't think they match 1-1 to the v6 car harness. did you repin any connections?

I used a computer and harness out of a 99 TA LS1 I changed everything from the firewall out

what about inside the car? what did you do with c220 -c230?

I'm not sure what that is but one of the harnesses went through the firewall and hooked up under the dash

I am almost 100% certain your problem is with the wiring in the BCM under the dash. You need to verify the pinouts between the V6 and V8 - these go back to the C220 and C230 connectors.