Looking for some kind of help on this guys. I have a '97 F150, 4.2L, nearly 150,000 miles and no proplems until this.

Its been pretty cold around here and this all started when I started the truck after being COLD, I turned the engine over a few times and as it started to fire I let off the ignition, it kind of sputtered then died, and thats when the light came on!

Went to the local parts store, they checked the codes, and it said "cyl. #3 misfire". So, I've now tried replacing all the spark plugs, disconnected the battery for a while, and everythings great, No check eng. light. I did notice that all the "old" plugs looked about the same (kind of dark/black), EXCEPT the #3, it was pretty "white" looking. I've also, now changed the fuel filter.

Drove over 200 miles, same deal, a COLD morning, starting it, it sputters and dies and the light comes on. Well, I've done this a couple of times, and about the same deal everytime, at starting up, the light comes on.

Couple other notes, truck seems to run like it has for A LONG TIME, gas mileage is about normal (a little under 18 or 17 mi/gal, highway and city.

PLEASE, ANY help, would greatlly be appreciated

 

Hi and welcome to FTE

How white was the #3 plug? Was it white or more tan?
White usually means it is running very lean or there could be coolant getting into it. I would start by checking for vacuum leaks around the intake manifold. You can take some spray carb cleaner and spray it where the intake meets the cylinder head, where the upper and lower intakes join, at the vacuum hoses etc. If the idle changes anywhere you spray carb cleaner at you've found a leak. You could also have a bad injector but there really isn't an easy way to test that at home other than by replacing it. Does the engine use any coolant? Ever see any white smoke? Hopefully not
Have you changed your fuel filter recently? It might be due. Was the P0303 code the only code that showed up? Did they scan it with the engine off and with it running?

 

Dave,
The plug is not REAL white, it is more tan/brown on one side and a little white to black on the other. I will try looking for vac. leaks (in the morning hopefully, it getting late).
Thanks, any other ideas, I'd love to hear them, although I would rather they stay away from that fuel injector though, this has been on my mind already.

Any comments on changing it out? I don't mind getting my hands dirty, but I don't want to screw myself, in the middle of it. I've got a repair manual (what I believe to be Ford's manual), which shows how, but I've never done something like this on my own. If you know what I mean.

Thanks,

Oh, forgot, no, never seen any smoke, and it doesn't use any coolant to speak of. I have added a little over the years, but I think I would be adding A LOT, if that was the problem, dont you think?

 

The plug being more tan than really white is a good sign. That and the fact that it doesnt use coolant means that you probably dont have a head gasket problem

Changing the injector is quite a big job. You have to remove the upper intake manifold and then the fuel rails. If you are going to do it make sure you have the manual handy and you'll want to pick up a set of upper intake gaskets before you start. You will also need "Spring Lock Coupling Disconnect Tools" to disconnect the fuel lines from the rails.

Hopefully others here might have some good ideas too.

 

OK, sorry for the delay, just got time to check for any vacuum leaks, and, not sure if I'm glad or not to say, I didn't find any vac. leaks.

Please, someone any other ideas, or someone else have this problem.

 

Could be the coil!