Join Date: Nov 2009
Location: Redford, MI
Bronco Info: '96 Black 302 XLT - '94 Green 351 E. B. both are E4OD, 3.55 axles, 31 10.50x15
No air filter? that's not good. Put a filter in it, and then check it in a couple of days.
Also check to see if your PCV valve is working (it should at least rattle, but as they are only a couple of bucks, get one when you get an air filter).
The PCV hose reroute (if it has not already been done) is to put the vacuum source for the brake booster at the back of the intake manifold, and take the PCV vacuum source hose and put that on the fitting that the brake booster was using. This puts the PCV gasses/vapors more in the middle of the intake manifold. With the PCV gasses/vapors dumping into the intake at the rear of the intake, the oil vapors, etc. can cause excessive carboning of the two rear cylinders. If you need to make this change, make sure the new hoses are rated for PCV use. A good auto parts place will know what kind of hose to use. IIRC, it may even be marked for PCV use.
"The simplest solution is usually the best solution" - Occam's Razor
"The significant problems we face cannot be solved at the same level of thinking we were at when we created them." - Albert Einstein