ls3 engine swap rx7 keeps dying despite being at a performance garage for 7 months.
The battery was recently changed to a 750cc battery, it was suggested maybe I have a bad sensor, battery disconnect or battery(dont think thats it, as it was recently changed and the new battery is covered under warranty in the car). so my guess is its a bad sensor, vats or battery disconnect or potentially a alternator?
Engine swaps are fraught with peril especially when electronics are involved.
You need to be more specific about what you mean by the engine "keeps dying" - doesn't crank, doesn't start, fires up and then quits immediately, fires up and quits at random, bogs down on the road, etc.
On the face of it sounds like the "performance garage" doesn't know what they heck they've been doing for the last 7 months.
fires up and then quits immediately. now the efi I have installed won't turn on when I turn the car on.
What kind of fuel injection system? We don't normally get involved with that kind of custom job here and deal primarily with people keeping their regular stock vehicles running. However if you provide more details perhaps a member here will be familiar with your setup and may chime in.
its a ls3 with the fuel rail on the intake manifold.