I had codes of P0302 and P0308, so I cleaned my MAF carefully, everything is still intact, changed my spark plugs, changed my ignition wires, changed my coil packs, and now I am getting P0301, P0302, P0303, P0307 AND P0308! I am running on 3 cylinders, the last change was the coil packs, and I connected them exactly like the ones that I took off, so I don't know what else I could do!?! I have intermittently had an error code of `System too lean (bank 1)` every once in a while, I don't know what else to check, can y'all please help? I have a 97 F-150 with the 4.6, I have changed plugs 5 times so far and wires 3 times, I have no idea what to do now. Please help!

 

I'll bump this one to the top for ya.

 

PM,

The first thing to fix is all other, non misfire, codes. So if you had a P0171, it must be addressed first. Here is a list of things to check. Fuel system: Excessive fuel pressure. Leaking /contaminated fuel injectors. Leaking fuel pressure regulator. Low fuel pressure or running out of fuel.
Vapor recovery system.
Induction system: Air leaks after the MAF. Vacuum Leaks.
PCV system: Improperly seated engine oil dipstick.
EGR system: Leaking gasket. Stuck EGR valve. Leaking diaphragm or EVR.
Base engine: Oil overfill. Cam timing. Cylinder compression. Exhaust leaks before or near the HO2 sensors.

When this checks out we can go for the misfire problem. BTW what plugs are you using and what are they gapped at?

Regards

Jean Marc Chartier

 

Thanks, WLF! JMC, I have Autolite Platinums gapped at 53, I had a set of Autolite Platinums gapped at 46 last change, hasn't made a difference, actually, when I started getting all of the misfires, I changed the plugs in the cylinders that were misfiring, and it did not make a difference. I wonder why it was only missing on 2 until I changed the coil packs (changed again, by the way, now I am only missing 4 cylinders instead of 5), I thought I would check the PCV valve next, I haven't found any vacuum leaks yet, and my EGR checks out ok on the computer, would it show up if it had a problem? I know on the computer itself, it says `EGR system ready` if I scroll through the components that it is checking, but maybe if it has a bad gasket, then it would show good on the computer. My O2 sensors are coming back fine, also, and unless it's very small, I don't have an exhaust leak, but I will double check it anyway. If I had bad injectors, it would make my plugs misfire, but I really can't afford to change my injectors out, I asm down to like 250 bucks now, I have already spent close to 500 on different parts. Made sure my dipstick was seated properly, changed my oil, made sure it was not overfilled, I don't know how to check my cam timing or my cylinder compression, but I would if I could. Especially the timing, it feels like a timing problem to me, it feels like the plug wires are just randomly plugged into the coil packs (not in the right order), because sometimes it will fire a little off, and it makes a really bad shudder. I have rechecked and made sure that I had the wires routed correctly and plugged in correctly, though. I don't know what to do. How do I test fuel injectors, and where is my fuel pressure regulator? Easy to change?

 

PM,

Before going any further; What did the plugs that you replaced look like? Were they fouled? Oil coated?

JMC

 

The number eight cylinder (the one that misfired first of any) was coated with oil (crud in general), the gap was bridged with stuff it was so bad. The ones that I replaced since then looked like they had burnt relatively clean though (no excessive carbon buildup, no crud on them). The gaps had moved from 53 to 54. They were clean as a whistle. I changed the number eight when it first started happening, though, and the new one that I changed out was clean, and now it seems the number eight isn't misfiring anymore, just the 1,2,3, and 7 (all of those looked good when I changed them out). The system too lean (bank 1) went away, too.

 

Sounds simplistic but may be bad wires. Try re-installing the old wires just on the plugs that are missing. Also remember to use non-conducting grease (spark plug grease) inside the boots to prevent firing to the block.
See if this helps.

 

PM,

I agree with WLF. try using a spray bottle of water and spraying the wires at night. If you see sparks those wires are at fault. If the plugs are not properly seated they will cause a misfire. Using a dielectric grease on the boot will allow it to slip over the plug treminal with ease. This will keep you from over excerting pressure on the boot and cracking the wire.

Regards

JMC

 

I will try it again, I will check them tonight with the spray bottle, it seems like I would have had it fixed by now if it was wires, though, I have changed them a bunch of times, but I will give her a whirl again. I will post back what happens with it. Thanks, y'all!

 

Any luck??

 

Just a thought, but did you reset the computer?

 

You could also check the camshaft and crankshaft timing sesors.

 

Try Having your cats checked. They could be pluged, I had a 97' with a 4.6 and had the exact problem. I chaned wires,coil packs and plugs after plugs after plugs, though the best plugs I found to work best were the motorcraft double platnums. I talked to some ford enginers I new and they told me they had a cronic problem with the cats plugging up on 97' and 98 ' trucks causing missfires and other funky codes, and said not to remove them but to repace them with new and emproved ones from ford beacouse It will sound right and even drive nice for a while without them but will cause problems later than you want to know. I trust these guys, they have worked for ford truck enginering for over 15 years and had a huge hand in the building of the new 97' to 03 ' design and the currant! Anyway When I found the cost of those cat I about S*#t my pants but that was my problem. They wre indeed cloged. My build date was 08-96 one of the first. It didnt happen to every one, but some . Ive sold the truck since then and went back to the early ones and hving fun . good luck and the price was $800.00 for the right and $900.00 for the left.


Mark

 

I had a P0308 misfire on cyl 8 and when I pulled the plug it too was fouled and had oil on it. Anybody know what could cause oil to be on the plug?

Anyway, I replaced the spark plug, coil pak, and fuel injector and so far my 2001 F150 4.6 is running fine. I think it was a faulty coil pak. I decided to replace the injector just to be sure.

Make sure the spark plug boots are seated properly and filled with dielectric grease or you may get another misfire.

Paul

 

Pickupman, you did yourself in by shotgunning the original problem and created more problems and total confusion for yourself..
Learn a lesson from this.
1. the maf had nothing to do with two cylinders missfireing, let it alone.
2. changing all the wires intead of just the 2 plugs, set you up for error.
3. spent money without proof of need.

a. go over all cylinder boots and make sure you use dielectric grease and use a twisting motion /feel that tells you the boots have engages the tops of the plugs and not jambed to the side.
b. verify the wire placement on the coil paks with known info.
c. reboot the PCM by power down or clear with a reader so you are not getting confused with 'old codes'. Always deal with the latest codes.
d. deal with a new set of codes and clear each fault and not try to include all in one shot.
e. if other codes are intermittant and donot show up at the moment, leave them for last after the most important ones are cleared.
f. after all this is cleared, you could still have other problems that are fouling plugs but have to get the imediate problems under control first to be able to judge that..

Unless you reform your logic thinking, it will give you a lot of grief until or unless you get lucky. You are dealing with a complex computer driven system with little understanding.
You must learn to work up the chain from the plug one at a time, for self service.
I'm sorry if this sounds a bit rough but you need to look at this from a different perspective.
Dispite all the efforts to help, some also cause you confusion.
A house is built from the foundation up and not just from a pile of wood.

Good luck.