94 Passport Won't Start

[SierraTraderMan]

I have a 94 Passport v6 with 214k miles on it.

Three months ago it developed the following condition: a) after it was about 1/2 warmed up it would start to balk; b)would start blowing black smoke; c) gas mileage dropped; d) check engine light came on; e)gas gauge started acting up (would read 1/2 then drop to empty.

I tried the Seafoam routine: 1/2 in the throttle body 1/2 in the tank. No change.

About a month ago, I stopped driving it - now it won't start.

It cranks - so I tried to prime it with starter fluid. It acted like it was catching on a couple of cylinders, but would not fire up and run.

Changed the fuel filter - no change. Has about 1/2 tank of gas.

Any suggestions on how I can diagnose this?

[Cat Fuzz]

Just throwing out what came to my mind:

Check the fuel pressure regulator. If the diaphragm inside ruptured, you'd get to much fuel and also suck extra fuel in through the vacuum line. There might be gas in the vacuum line itself and that is your clue. Try pulling the fuel pump relay or holding the gas pedal to the floor while cranking. Either method will cut-off fuel allowing the cylinders to dry out. you could also have a leaky fuel injector or two allowing fuel pressure to continue pumping fuel into the intake manifold until the residual pressure bleeds off.

[SierraTraderMan]

Thanks for the reply - I check those and they were ok.

It occurred to me to check the plugs. The first plug wire and plug was covered in oil (I suspect the valve cover gaskets are leaking).

I changed all the plugs and bingo it started right up.

It's blowing white smoke now, which was not present before and I hope is the residual SeaFoam in the system.

I am wondering if I have a partially blocked oil return from the valve cover to the pan? Is there some method (such as using oil cleaner, then changing the oil - to break down build ups)?

The valve cover on both sides leaks - maybe the gasket is shot, maybe the oil is not draining properly and just sitting, thus leaking.

Any suggestions

[Cat Fuzz]

White smoke usually indicates that coolant is getting into the combustion chamber. That usually happens with a cracked head or blown head gasket. Seafoam in the gas would not cause this. It's possible that there is some condensation in the exhaust from sitting but it is unlikely.

The oil in the spark plug tubes is a pretty common problem. They actually make updated spark plug wires that keep the oil away from the plug. Napa has them.