I have a friend with a 91 EB Bronco 5.0 and here is the problem... the engine is runing like crap. I have replaced the plugs, wires, cap, rotor, PCV, air filter. breather filter and fuel filter. When I pulled the old plugs out, they were wet and you could smell the raw fuel on them. The CEL is on, so I tried reseting the computer but that did not help. I'm thinking that it is the O2 sensor, but am not really sure. The truck cranks a little long, but will start and stay running, until you try to shift out of park. When shifting into reverse, the RPM's drop and it stalls. So the only way to move it in reverse is to two foot it.... one foot on the brake and the other on the gas. The same thing happens when shifting into drive... however, once you get moving everything is fine. Even when coming to a stop the engine has no problems with keeping running.
There is also another problem that could be related, but not sure... when restarting the truck after a stall... the guages 'flip' out. What I mean is they flucuate radically. Could this all be realted, cause I'm thinking that it could use an alternator as well. Considering it's got a 167,000 on the original.
Let me know what you all think so I can help her out.

 

If the CEL is on, Pull the codes, you can do it with a paper clip you can read how to do it here

 

if you can see and smell gas on the plug, maybe the spark isn't what it should be? might try replacing the coil and or TFI module located on the distributor. MSD makes a good replacement TFI coil that's only like $50. good luck.

 

look at the fitting on the fuel rail.....have the fuel pressure tested.....a faulty psi regulator will dump too much fuel into the engine wetting the plugs.

Another is a weak spark....coil or module

do get the codes pulled....