My 1978 280 Z car

Thanks!

Actually it turned out that way. We kept talking the thing around and discovered that argneist's car was only running on cylinders 1-3, give or take. The problem, which argneist discovered, was that the EGR passage was eroded through to the intake manifold (i.e. bypassing the EGR valve and dumping exhaust into the rear of the manifold). We were all astonished. Kudos to argneist for sticking it out and discovering this weird issue! Oh, the end of the story is that he disconnected his EGR. End of problem!