'94 Roadmaster Won't Stay Running

I've searched the forums and hav'nt found this problem come up yet so here goes. As it says in the title my roadmaster won't run. Sometimes it fires right away and sometimes it takes a bit of cranking to fire. But it never stays running past letting go of the key for more than a second or two. The check engine light isn't on and i've checked for fuel and spark and have both. I'm not very good with fuel injection and computerized engines. I've always been a carb guy myself so if anyone has had this problem or may have some suggestions please help. It has the 5.7 with the 4L60e if that helps. Thanks in advance for any help you can guy's can offer.

Check for injector pulse, you can use a noid lite, the autostores sells them. The noid lite will show that the injector has voltage and ground. If no ground look for rpm signal. Also, use a gage and check fuel pressure, some of the national brand autostores used to loan out a fuel pressure gage, if you don't have one.

I needed to correct something, if you have good spark, there should be an rpm signal. With opti-spark ignition, there is no bypass ignition, according to my info.

Thanks i'll give that a try.