my van runs rough like there is a miss, no power and stalls. no 2 post on coil pack was fried plugs were fouled. replaced coil pack, crank sensor, tps, aic valve, some hoses vaccum lines were shot replaced them. took the valve covers off, even cylinders looked good but even odd cylinders looked dryer with corrosion. now im onto the timing chain need any tips you got to get the crank sprocket off.