I've been working on my 88 5.0. When I start it, it runs good but as soon as I let off the clutch it stalls. Nothing I do stops it. It has never done this before and just started the other day. Is there some kind of adjustment with the saftey switch or something that may have gotten out of wake. Again, I start it with the clutch to the floor and as soon as I start to let off it stalls. I can keep on the gas and nothing helps, just dies. Any help would be appreciated, thanks.