I have an '88 bronco xlt with the 302 in it. I recently was tuning it up because I suspected there was a fouled plug. I found that the #8 plug was destroyed, there was no electrode left. I ran a compession check and found all cylinders were within 10 psi (150-160) with exception of the #8 cylinder which had 0 compression. I then did a leak down test, it was the first time I'd done this, and when I applied air into the cylinder air was escaping out the tailpipe. I accidentally broke the vaccum lines for the coffee can (don't know the formal name). I had been driving the truck and hadn't had a problem. I switched the battery with a better one that I had around and replaced the PCV valve because I had forgotten that at the time of the tune-up. Now the truck is running o.k., considering the dead cylinder, but when the engine is idleing or coming down from higher rpms it dies out. It will idle but once it stumbles it really wants to die. I know this is kind of vague but I don't have any good ideas. So I'm wondering if this rings any bells or if anyone has any suggestions about what to do with the engine. Like taking off the valve cover or if a novice should leave that to an expert. Any ideas would help. Thanks By the way the engine was rebuilt about five years ago. It had been fairly well maintained. Which means not always on the numbers but usually pretty close like maybe 4,000. It never overheated or ran dry of oil.

 

[updated:LAST EDITED ON 03-Apr-02 AT 10:52 AM (EST)]If you have no compression on the #8 cylinder chances are you are right about a bad valve. The only way to fix this is to pull the head off. Changing the head out is very simple. As long as you have a torque wrench. Buy a Chiltons or Haynes manual for the torque specs and replacment procedures. Personally I would send both heads off and have them reworked. Chances are you may end up having to put a new seat and valve in the #8 exhaust. Or worst case you could have a burned valve and a hole in the top of the piston. Just remember to mark the lines and wires where they came from.