the car had remote start which worked great before the swap, now with the ls1 the remote start will turn the car over and even run for a split second but then shuts off.

any idea what could cause the difference?

 

It would be my assumption that the LS1 PCM doesnt like the fact that the key isnt in and the ignition switch isnt on. So that when you use the remote start its sending power to the PCM and the engine which allows it to start for that moment, but then the constant power flow that would usually come from the ignition to the PCM when the ignition switch is on stops and the engine doesnt want to run anymore because the PCM isnt getting the power that it needs. Why that would be different from the old motor that was in there is beyond me, but I am sure it has something to do with the cutom wiring for the LS1. Thats how I see the problem being... but I could be wrong.

 

interesting... thanks.

 

Did you happen to get this problem worked out?

 

no unfortunately it's on the back burner right now, basically looking for suggestions for when i go to fix it here in a few days but i appreciate it.

 

The VATS on a 4th gen car is different than the VATS on a 3rd gen car, on an LTx and LSx based car, the VATS turns the fuel pump off instead of whatever it does to a 3rd gen car when there is no key in the ignition. From what you are saying, this is exactly what it sounds like. Before I had the VATS programmed out of my PCM, I started the car, it ran like 2-3 seconds (from the rails being filled by the prime) then shut off after it ran out of gas.

 

in theory that sounds great, the problem is i have it turned off in order to by pass the key and it's still doing it? definately double check it all though, good suggestion. thanks.

 

most remote start boxes use a tach input.
assuming you have that hooked up, the remote start box needs to be set for the 4 cyl pulse that the LS1 produces.

right now, it starts, and doesnt register that the car is running, and kills it...


if that is set correct, then it might not like the LS1s 5v "tach" signal when its expecting a 12v Tach signal.

 

it is set, never hurts to check again though.. appreciate the suggestion.