2004 cavalier rs problem

I'm having an issue with Crmestopper RS830 RS with a GMSL bypass in a 2004 Cavalier. When using the RS, sometimes it will work on the first try, sometimes it will take 2-3 times, and other times it will take 10-15 times to get it to stay running. It seems to acting like the anti-theft is being bypassed. It doesn't matter what the weather or temp is. I tried running it tachless and in tach mode. I've replaced the brain as well as the bypass with the same results. I went as far as checking all my connections for bad solder joints. Luckily I have an understanding customer. Any help would be greatly appreciated.

I'm using the ground out when running wire. I've done alot of these cars and for some reason this one's being stubborn.

It may be the wiring and not the modules you need to replace. Sometimes the wires at the plugs don't make contact with the pins or you could have a broken wire inside the insulation. I would suggest try replacing the critical circuits that could cause this. Powers. ground, tach, etc., until you find the problem.sparky