Carbureted LSX forum - car wont stay running HELP

fired new engine for first time. You can pat the gas and it will fire every time but goes dead almost immediately. Doesn't matter if you keep giving it gas.

What should I look for?

I have fuel pressure and fuel in the Carb, it sprays fine when you hit the throttle.

Could it be a sensor? I reused the old ones

Did you get your alternator mounting firgured out or are your firing it up without a belt in place? The MSD box requires a solid 12v source so if your batt is being knocked down from rolling the motor it might not have enough left to fire the box for long........again, assuming you dont have the alt working.

Thanks. I had the msd wired to a 12v source with key on, but its losing power. I hooked the msd to a good 12 v source and it fired right up. Now I gotta figure out the wiring issue.

And yes on alternator, I finally ground on the bracket and the bolt head and it works great. Thanks for your help

There was a problem with the factory 12v source dropping?

Yes zone, haven't had time to pin point, but believe its ignition switch

Run the 12v lead directly to the battery (just for test purposes) and see what happens

Pretty sure that is what he did to make it run.

The switch may be bad, unless it has a resistor to drop from 12 to whatever.

Yes, right now I have it on a toggle switch which will work for now.

Next problem is car has battery in trunk with master disconnect, which doesn't kill the car cause of alternator. I notice they make a disconnect with wires for an alt but mine doesn't have it. Is there any way I can use the one I have? Like run a wire from lug of alt to battery?