I have a aps787 remote start on my truck when I go to start it it will turnover and attempt to start but die then keep trying to start but never stays running

With a scanner that can control output
Look for TPS % data
If it shows 1 or 2 % (no fuel pedal depress)
Reset it
It must read 0 % (no fuel pedal depress)
Run the engine to check if the problem is solved.

First make sure the batteries in your remotes are good. If they are good then I would say you have a defective unit.

This might sound stupid, but have you tried first replacing battery in remote, this could cause this instantly, just like a TV remote. First try that. Hope that solves it right away.

I take help from online websites that have this service like helping in repair some like reliable-store have instant help.. others are a bit slow which I don't prefer... rest is up to us.. U get free manuals

Prestige APS787 user manual

You can download the owner's manual via the following link:

http://audiovox2.info/docs/common/APS787/APS787_OM.pdf

This unit has gone through a few revisions, for other related manuals see the following link:

http://mobile.audiovox.com/findmanual/?findManual=787&x=0&y=0

where did you get it installed? what kind of car is it? unplug the brain of the security system and see if your car starts

You can click on this link,
http://mobile.audiovox.com/AudiovoxInfo.do?findManual=APS787+&x=12&y=9

it could be that he locked the car with the key and activated the car alarm try unlocking it with the remote and see if that works

try adjusting the shock sensor under the dsah. its a small black box connected to the alarm with 3 or 4 wires coming off it.