I have a 95 Ford Aerostar with a 3.0 engine I just replaced both cylinder heads. after I got the engine back together , and started the engine I noticed right off that it was backfiring through the intake manifold. after shorting out a couple cylinders determined it was the number five that was the culprit . Now I checked the heads out as well as the valves and appear to fine so all I can come up with is the valve is sticking . Now my question is what can I do to get it to unstick ?
Thanks in advance for any and all advice.