I just completed my ls1 swap. I have a 99 ls1 from a Trans Am. It only has 4,500 miles on it. I can get it to turn over but it wont fire. I have spark and good fuel pressure. I disabled the vats from the ls1 but not the 91 camaro. The injectors are not pulsing. Any ideas? I also replaced the crank sensor and the ls1 is not throwing and codes.

 

I thought I would add I am using a full plug and play harness from Speartech. I have checked all my fuses and they are all good.

 

If the injectors are not pulsing its a VATS issue within the LS1 PCM. If the injectors are firing ( use the test light injector trick google it ) anyways if they are firing but not shooting fuel then verify your fuel pressure. It should be 58-61psi and no higher. Higher PSI at the rail can keep the injectors from opening ( they're just little servos in there ) and failing that? While cranking the engine over try tapping each injector on the side of its body one at a time with the end of an 8" or so 3/8" extension. When they sit for a long time sometimes the get seat stuck. A lot like a starter that needs a tap to shake the brushes a little before it will crank.

 

Cam and crank sensor good?

 

I tapped on the injectors and it fired right up. Thanks for the help, it sounds like it has been running this whole time.