My 98, but your 2001 should be similar. I had a 2001 for about a year. The 98 put it shame, -so I sold it lol.

Yellow = Ac Accumulator Bottle.
Red = Look for harness to be resting on top, by this connector. Inspect if it is.

 

I checked the wiring harness and it's good but it was a good suggestion. I can see where that would be a problem. 3 codes were thrown today P0308, P0316 and P3000 (unknown). I'm going to take some time tonight and just start over. I'm going to pull cops, plugs, etc to make sure everything is dry and nothing is fouled. I'm also going to check the fuel system to see if the pressure is there and nothing is clogged. Maybe by chance I'll hit on something.

 

So far from what I have read, you have had misfires on cyl 4, 7 and 8 along with "random misfire" and "misfire detected on startup"

I would check the tire pressure....
J/K

But if the misfire is moving around that much, I would check fuel pressure. Or ecu, electrical issues.. Or the worst set of cop's Ive seen. You happen to pull the plug on any of the misfires to see what it looks like? Or instead of swapping cop's swap the injectors on that cylinder. You may have got some nasty's pass through your old filter before you changed it and are still causing issues with your injectors.

Also, you said in your first post you had been chasing a misfire before you swapped your plugs and cop's. Were there any codes before the cop and plug swap? And what did those plugs look like when they came out.

 

Toyz, the state of mind I'm in I almost bought into the "check your tire pressure" comment. You asked about codes before I did the cop swap. I did get a P0304 so I pulled both the cop and plug. Both looked fine but I swapped the cop with #1 and nothing on 1 or 4 since.

I went to check the fuel pressure earlier tonight and realized that my pressure gauge does not have a schrader valve connector. I went to buy one but can't find a connector anywhere. I even went to Advance to do the loaner deal and wouldn't you know it they didn't have another fuel gauge in house. See why I'm losing my mind?

I'm thinking as well that it has to be something with the fuel pressure or dirty fuel. I'm going to work on it again tonight and will let you know. BTW if you have suggestions on checking fuel pressure without the correct connector I'm game.

 

Yea, - you just clamp it when you don't have the fitting. It's done all the time lol.

 

Yea I sort of remembered that after I posted :o

 

Check a couple grounds. Important grounds. PCM ground on the firewall by the battery. Bolt should be be green. Clean the connector (wire brush). Wire wheel the paint off the firewall, wire wheel the bolt. Tighten it back up.

Firewall to engine ground. On the firewall/passenger side , above #4 coil. Clean the same way.

In case you have grounding Gremlins. Just those two. It's more less a chain for engine controls. PCM to Firewall/ Firewall to Engine.

Running out of stuff to check. I think I mentioned this already, -but disregard all DTC's other than your misfire DTC's. - Rule of thumb = Misfire first. Once that's handled, it most likely will get take care of accompanying codes that follow.

Also, always troubleshoot fuel system , pressure/regulater.

So, are you sure the springs are connected to the coil blades good? Should be able to give them a little tug without the spring coming off the coil.

Also, never force the coil onto the plugs by bolting down the coil. Twist back and forth to mount the plug. Dielectric grease is needed to mount the plug correctly. The silicone boots are weak, they will fold/buckle without a little grease to assist. It happened to me once, -on # 4 of course.
_______________________


Did you mark the bad coil in the set your removed, - the old set? ? Because you might wanna reinstall you old set to verify whether or not it indeed the new coils.

If you have to mix a Global coils in with the old set, just don't include coils that were on miss firing cylinders, -know what I mean?

If you don't make any progress towards figuring it out, - Compression test it. - After making sure it's not a wiring problem. Did you leave the battery connected while working on it ? If so, the PCM may be hurt and cause buggy coil drivers.

Something happened or , well. You had a miss on #4/ swapped w/#1 and that cleared it up. So, you had a bad connection right? Yea, you did. And this was with the Global coils correct ? Or was that before you installed the new coils ? Holey crap, bring that thing over here lol.

 

Okay...next chapter: Checked fuel pressure and sure enough it was low. When put under load the fuel pressure went down considerably more. Replaced the fuel pump, filter and cleaned tank, etc. Improved significantly BUT threw a code on #4 again. Put back under load and disconnected cops one at a time. Number 4 cop was fouled/cracked but plug was still good (important point...this was the only old cop on the truck as I used it for a test). Replaced cop with the new one and runs much better. That all said it is still misfiring under heavy load. The mechanic that replaced the fuel pump, etc. said that he believes the misfires will clear up in a day or two. His theory is that after the problems with fuel pressure that there are deposits that need to be burned out. If it does not improve in a day or two he wants me to bring it back.

So it's better but still misfiring and I'm not sold on his theory (could be convinced but just not there yet). I checked both the grounds and they were actually very clean; no corrosion at all. What do you think of his theory on the misfires clearing up?

PS - The mechanic (Jeff) went behind me and checked the cops to make sure they were installed correctly. I'm glad to say I at least past one test in my life :-). Oh and I have been removing the neg battery cable before working on it.

 

If you have deposits that are bad enough to cause misfiring, you should get a BG or Motorvac job done.

 

What's a BG? I looked up the Motorvac stuff.

 

I was chasing a misfire for the last 5 days and it was only getting worse...
#8 misfire...then #2 misfire...then the engine light was flashing on the dash and I said no more...
I added fuel system cleaner...heet...
took out the gms cop's and put old fomoco ones back in...
finally removed 3 week old (500 mile)e3 diamond fire 3.70 plugs and installed champion 7989's...(.045 gap)

she runs like a top again...no more missing...just stomp and go!!!

now I just have to send the e3's back to Jegs and hope I get some money back...

Oh..."DON'T BUY E3 3.70 PLUGS FOR YOUR 5.4L 3V"

Thanks

 

Well why do you keep buying crap ? - Not to many will even run E3's. Granitellies have long history of problems in the 2 AND 3V. "Neet" is just snake oil and now your running Lawnmower plugs (Champions).. Hell. Lawnmower's don't even run right on them half the time The way I see it, you are your trucks worst nightmare lol.

Yea, stomp on it and go. - While it still does....

 

We have a member with 6000 miles on E3's in a 3V, so those may not have been your problem. However, I've never heard anything good about the Granatelli cops.

Now we have mixed reports on both the Champion and E3 one piece plugs..........

 

This morning code P0308 for the second time. Pull cop again and this time it is obvious something is wrong. The bottom of the boot was ballooned on all sides symetrically which proves it was on the plug but also something happened. Pulled plug and it looked great. Had one more new cop and I put that on, fired the truck and it was better BUUUTTTT still freakin missing.

So we know the fuel pump was bad which obviously affects the fuel to the cylinders and #'s 4 & 8 now replaced. What the crap else could be going on? Changed PCM from custom tune to standard, back to towing, back to custom. Misfires no matter what I'm running. Grounds are all good. Cuss a duck.

For those of you that now all about Fords I own a Festiva (93) with 220k miles on it. That is now my primary car and while it's fun I'm 6'6" tall and 290lbs. I NEED MY ^&*%$((*&%%**&*^((&%%$$ TRUCK.

I feel a little better now.

 

I think your mechanic skills are the root problem with your truck. As you are trying to fix stuff you are creating more issues. This leads me to my conclusion.