Idling problem

Yesterday, I went to start my 1992 GMC Safari XT V6 and I noticed that it wouldn't idle correctly. It kept pulsing until it would eventually quit. I kept trying and it wouldn't idle. I could get it to stay running as long as I held my foot on the gas, if it was in nuetral or park. I figured that I could drive it as long as I kept my foot on the gas. This morning, I drove it to the end of my road (little over a mile) unti I came to a stop sign and it quit on me. I put it in park, started it up, put it in drive and hit the gas and it stalled. Managed to get it home by pumping the gas pedal all the way. This evening, I kept working with it until I got it to idle correctly. It idles fine now, until I put it in gear. Then, I took the EGR valve off and cleaned it to make sure it wasn't staying open. Didn't help. Is it possible that the EGR valve has a hole in the diaphram? If it's not the EGR, then what could be my problem? When the van is in gear, it won't run even if I floor the gas. It just stalls out. When it's in neutral or park, I can rev the engine all the way. I can floor it. It does fine. I just can't go anywhere. Help please!

Is your engine light coming on at all? If it is then you can use a paper clip to get an engine code and that may help you narrow down the problem.

Nope, not getting a light. It's agravating the crap out of me. The other day, I had it running good, but when I tried to go, it stalled out. I've got it to idle in park and neutral and it will idle ALRIGHT in drive or reverse, but has very little power when trying to go or it just stalls.