Spent the past week doing a timing job both sides 2007 Explorer 4.0 SOHC . After I triple checked everything, it's not running right. It'l start up one time and run for as long as I press the gas when I let up, it dies and won't start again for an hour or two. I have the special tool to hold the main crank and the overhead cams in the correct position so I don't know why the timing would be off? I hate the thought of taking the engine out again .... the only thing I can think of is that the final time I set the crank at TDC for Cylinder no. 1, I did not hook up my homemade hollowed out spark plug with a rubber glove on the end which inflates like a ballon indicating the piston is in the compression stroke. Is it likely that the piston was at bottom dead center even though the keyway in the crank was at high noon when the two cams were set? Any way to test that theory before removing the engine a g a i n arg!