I have a 1991 Camaro. We have changed the spark plugs, which were carbon fouled, and have gotten a new battery. The people we bought it from said it was working great until they changed the EGR valve. Now I can’t get the car to start. When it did start the tach is usually around 15 to 20 RPMs. It would drive for a little bit but if I turned it off it wouldn’t start again for another couple of hours. Then if I put it in park for a little while it would die when I tried to drive it again. It wouldn’t start after that for a couple of hours also. It will not start at all now. My step dad thinks that something might be wrong with the chip on the key. Can anyone help me?

Have you checked the current EGR valve if the vac. line is connected? Check all the vacuum hoses for any cracks or leaks. I don'tthink the chip on the key is the problem because it would cause a no-start rather than a hardstarting.Remove andinspect your new plugs youjust installed. They may have becomefouled again preventing you from diagnosing your problem. You may have to reclean them.