90 2.9 fouled 1/2 plugs, smells, rough start

[lyttek]

1990 2.9, 5spd

5 months ago I replaced cap, rotor, wires and plugs. It would start just as soon as it turned.

1 month ago it started cranking a bit before starting.

1 week ago it started rougher, and is now missing on 1 cylinder consistently, and while driving, I can feel another kick in and out, like a bad wire or plug would do.

Pulled all the plugs. (platinum) All drivers side plugs are black, lots of buildup. Center plug smelled strongly of gas. Replaced that plug yesterday.

Passenger side plugs are nice and clean.

Pulled center driver plug again today; it's caked with soot already, so running rich.

Is there anything common between the drivers side plugs? Would a too-rich problem cause the hard starts as well? What to look at next?

 

[2.9XLT]

Are you getting bad mpg? If you are then the injector might be stuck open.

 

[Big Jim M]

Find the exact plug that came from the factory and install a set of them!! ALL other plugs are a crapshoot when you buy them. NO PLUG can do more or better than the original plug.. All a plug must do is to fire and stay clean at the temperature that Ford built the engine at.
Just because the plug you buy is in a bright red box doesn't make it better.. Platinum only makes a plug last longer.
I'm betting them plugs are too cold or your engine isn't running at the temperature it needs.
Big JIm

 

[lyttek]

Here's the thing:

ALL the plugs on the drivers side show signs of it being rich... that's what baffles me. If it were just one, I'd think stuck injector... but three? I just mentioned the center one specifically to show how fast it seems to soot up heavily.

I'm beginning to think I might have a bad set of wires. It wouldn't be the first time that problem has cropped up. I've been running platinum plugs for years in this truck with no problems, and the plugs on the passenger side look like they're brand new.

I'll be tearing into it tomorrow to see what else I might find.

 

[Psychopete]

Check to make sure that your fuel pressure regulator hasn't ruptured - after it's ran, do you have fuel in the vacuum line from the FPR to the upper intake?

Pete

 

[lyttek]

Check to make sure that your fuel pressure regulator hasn't ruptured - after it's ran, do you have fuel in the vacuum line from the FPR to the upper intake?

Pete

BINGO!

Now I'm wondering how much fuel might have gotten into the oil :forehead slap: