I have read numerous threads on this but have not found exactly what my
97 Ford f-150 4.6 V8 is doing.
Last night I drove home from work and my truck ran fine.
This morning I start it up and it is running real rough as if it is not running on all cylinders. I drive down to the store hoping it will start running smooth but it just spits and sputter all the way to the store and also about half way there the Check Engine light starts flashing. I took it to Advance auto parts and they put the reader on it and it showed "Misfire # 1 and 3. (he did'nt give me any codes)
I replaced the plugs and wires with ford parts about a year ago. The truck has 156,000 miles on it and this is the first trouble I have had with it. It has been a great truck.
My biggest question would be is how can it run fine the night before and then the next morning have 2 plugs missfiring.
Women are like that. Sometimes you don't know if you should take a bow or run away!
Water in the fuel, injector plugging etc might be a cause or even moisture in the plug wells for those cylinders, can cause fast changes.
Look beside the alternator and below the upper radiator hose on the passenger side. Follow the wires that go to the passenger side plugs, they will be running off the coil for that side. Sorry this was the best photo I have of early 4.6.
Thanks for the pictures, I changed the passenger side coil pack and it still runs rough. I added some heet water remover in gas tank to see if that helps. I pulled the #1 plug ( I guess it is # 1, first plug on left facing the engine) it was black and gunked up. I cleaned it and put it back in started the engine and still rough. I pulled the number 2 and 3 plugs and they were both clean. Could the egp or epr or epg valve (whatever is called) be causing this? Because that showed up on computer check but the guy at advance auto did'nt seem to think that was any big deal. Is that the valve on the back right (facing engine) of the intake manifold that has a metal hose going down to the exhaust manifold?
A black and gunky plug is never a good sign when you pull 2 more and they are clean - unless the plug itself, the wire, the coil, or the fuel injector is bad. At 156k, it's very possible you fried a valve or ring.
EDIT - What torkum said.
2003 F-150 XL RCSB 2wd 4.2 M5OD 3.55 LS
I brought my truck by the shop but they can't get to it until wednesday.
I do have one question,
I i pulled the little grey conector off of the #1 fuel injector and nothing happens, and then I pull the one next to it and engine runs even more rough.
Does this mean the injector on #1 is bad and not getting fuel or that it is not getting fire.
I have replaced: both coil packs, plugwires (lifetime warranty) plugs (Autolite plat.) EGR valve, fuel filter and air filter.
When I run it and then pull #1 plug, it is clean but does have what looks like oil or gas residue on it but if I put the plug into the plugwire and ground it I get a good spark.
Also I have no smoke coming from tail pipe.
I just trying to figure it out before I bring to shop,
Do they make a compression tester that will reach down into the deep hole where the sparkplug is? I am almost leaning towards the bad injector because I just pulled the plug again and looked at it and it is really dry except for a little oil, I mean not enough to coat the tip of your finger, but no gas smell.
Also when I pulled the plug wire and left the plug in the engine and ran it to test the plug wire the engine did not really change any as far as the roughness went.
I am going to try another garage tomorrow and try to get it look at earlier.
Thanks for your help and I will update what I find out.
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