Remote start, engine dies after 3 seconds

Here is the deal my RS stopped working after battery was disconnected for an extended time. Blew engine on 02 Grand Prix, battery was removed for 6 months- after engine was replaced and battery connected RS starts engine then dies after 3 seconds. Manual control of throttle- no change engine still dies. RS is Clifford 50.5x has a GMBP module connected. System worked before and nothing was really changed other than engine. Via key it starts and runs fine. Keyless entry works and it does start it for a bit- so the RS is working. Would I need to reprogram the GMBP again? I purchased the car this way so I have no idea how everything was installed. I have installed other RS units but have not used a bypass. Clifford manual says it is likely bypass or tach wire. When tach wire is disconnected engine does not actually run. Looking at the install manual for the GMBP it says to follow install "2" no programming- which is how it appears to be connected. LED on GMBP never lights up. Nothing under the dash was ever touched so no wires should have been disturbed. Any ideas?

Is the tach hooked up from the clifford to the vehicle. It should be a PURPLE / white wire on the remote start. It sounds like the the tach wire either needs to be programmed, hooked back up, or bothI drink current, eat ohms, and bleed voltage

Tach wire is hooked up and working. I think it is a purple wire w strip connected on a loom up by injectors. When that wire is not connected the engine tries to start but fails to really run at all. I changed the jumper to "tach threshold on" and engine will not run, learned the tach per Clifford manual- this is what it does. Using the clifford shutdown log it shuts down for "3 low or no tach" but without the tach wire connected it does noting. I am wondering if either the factory alarm is interfering or the GMBP needs to be re-learned and that the car is cutting power to the engine. I did notice yesterday the factory LED up by the windshield blinks. None of my other cars ever had an LED up there (just the spot for it).

Make sure the Gmbp is getting power when it goes to remote start. Power, ground, gwr..if the bypass isn't being powered during remote start the car will do as describedI drink current, eat ohms, and bleed voltage

I would re-program the gmbp module.I was going to say long tamper mode and turn the key on for 10 min.But since it starts with key fine that eliminates that problem.

Check the ground while running circuitI drink current, eat ohms, and bleed voltage

So do you guys take it that there is no way for me to program this since I am using it on a vehicle that is listed as "install 2" and it states "no programming needed"? The way that I read the install instructions there is no way to program it for my application. The funny thing is there is a purple wire tapped into the OBD2 port like in "install 1" so I wonder if the installer started the install then realized it was an install 2 and that was not needed- or maybe I am reading the install notes wrong and I need to hook it up via install 1 then later as install 2 after it is "programmed". I blew a brake line on the car so that has had my attention lately. I plan to go test it to make sure the GMBP has all working connections needed.

So not sure what happened but it started working. I fixed the brake line and an engine error code for evap system. Went to test the GMBP and the dang thing started. Really not sure what happened but it works so I guess I should count my blessings.