2000 F150 Triton 5.4

engine is ok at idle. Has a single cylinder misfire when under heavy load or 50% + throttle.

Not setting a p0304 yet, but went into mode 6 with the scantool. Found 8000+ misfires on cylinder #4. Swapped plugs, coils, boot and injector with cylinder #3. Misfire continues on cylinder #4. Also checked and found good back pressure at the exhaust. Verified good spark and checked fuel circuit with a noid light. Compression is 145-160 on all cylinders.

Any ideas?

oh yeah. Also checked for vacuum leaks. None found.

 

wow the exact thing is going on with my truck, but i did pull a p304 and did all those test.

 

After you swapped the stuff for #3, did you clear the previous code? It's a thaught.

 

Yes I did. I actually never set a code, just had a bunch of misses on #4 in mode 6.

After swapping the coils, I cleared the misfires and test drove again. I continued to gain misfires on cylinder #4.

This afternoon I started the vehicle up again and found the vehicle had a terrible mis that hadn't been there before. I set a p0302. Thought maybe I left an injector plug loose or the injector seal fell off. I went ahead and replaced coil on cylinder #2. I still have the original problem, but in mode 6 I no longer am getting misfires on cylinder #4. The ecm now detects the misfire on cylinder #1, 5, and 8.

I swapped coil #5 and #6. I then got misfires on #1, 7 and 8.

I'm wondering if I don't have faulty coils on different cylinders and maybe the ecm is detecting the wrong cylinders. (Even though #2 and #4 aren't even close together in the firing order.)

Tomorrow I'm going to order 3 more coils and start swapping them out to see if the misfires don't go away on the other cylinders.

 

oh yeah. I work for a GM dealer and can get AC Delco parts for wholesale on a cash ticket. Are the AC Delco coils as good as the OEM's?
They are a dollar more than OEM's on rockauto.com

 

Now my misfires are on cylinder #1 and #3. I had no misfires on 3 this whole time. Now out of 6300 misfires the only cylinders it detects are cylinders #1 and #3.
I'm starting to think these ecms have a difficult time figuring out which cylinder is actually setting.

 

mode 6 data on that scan tool sucks...where is the total missfire numbers?
does that scan tool have a screen to view power balance so you can drive and monitor missfires as they happen?

 

No power balance. I never purchased the enhanced stuff. Just wanted a cheap $150 scan tool I could use to graph sensors and check and clear check engine lights with.

I have a co-worker who has a $4000 snap-on solus. We looked up the same info on his and got the same results but never did a power balance. He has all the enhanced software on his, maybe that should be the next step?
Like I said I'm a GM tech. I'm really good with the Tech2 which has a misfire graph and a current misfire counter, this Ford stuff and mode 6 is all new to me. When I clear the light $56 resets to zero then starts climbing again. My guess (although I'm not to familiar with fords in mode 6) is that the total misfire is the 6299 #.

#56 is the only one that starts at zero when you cycle the key. All the others keep their value.
The "converted" info is what shows up if I go under Generic Info under a 2000 Ford F150. If I enter no vehicle info the scantool shows different values, even though the info translates into the same information.. See below. Same amount of misfires, just shows a different value.

 

You can buy a whole set of 8 OEM quality cops with lifetime warranty on Ebay for about 80 bucks. Search for DG508 and buy them from Global or Uneek.

 

have you pulled any plugs yet? what brand are they? multiple times i have ran into missfire issues with aftermarket plugs. Sometimes people get away with it but I can tell you from experiance motorcrafts work best. Chech that out and make sure when re-installing the coils you put a dab of dielectric grease inside each coil. If you still have missfires after that I would replace those 2 coils and retest again.

 

When I swapped the plugs, I found most where motorcraft. I found two autolites out of the 8. I was told two of the cylinders have been helicoiled a while ago, so my guess is the cylinders with autolites are the helicoiled cylinders. No excessive carbon build up, didn't appear to be running lean, etc. I'll go ahead and replace all 8. I've never seen a misfire jump around to different cylinders like this before, EVER. It's really frustrating chasing around a misfire that may be stored wrong instead of focusing on one particular cylinder. I think I'm going to just replace all 8 coils since I've had misfires on only 4 to start. Then a dead mis on 2, then a misfire on 6 and 8. Then a mis on 1, 5, 6 and 8. Now a misfire on only 1 and 3. If I didn't know better I'd think that fords ECM has a hard time detecting which cylinder is misfiring. (My guess is that Ford's don't throw p301-8's very often. Just p0300's.)

I don't really have time to wait for shipping. I can get Ford to wholesale the coils to my work and pay a 10% mark-up, or I can get ACDelco stuff for dirt cheap on a cash ticket. Do you recommend OEM over ACDelco? I know that we as a GM dealer put alot of delco parts on instead of OEM due to the fact that they are OEM quality, but cheaper.

Also thanks for the quick replys and help.

EDIT: I found those coils from Global. That's a hell of a price. Do they crap out as often as the Fords? Has Ford revised the coil to add better windings. etc or are OEM coils still built to the same specs as the originals which seem to fail?

 

I have no clue really about the ACdelco coils. But that doesnt mean i wouldnt use them. If you can get a better price on them I would use them its still a good known brand. But plugs I would stay with motorcraft.

Another thing to check would be for water in the fuel. Take a good litre or so from the schrader valve on the fuel rail and see if any settles to the bottom. Ive been bit by that before as well. Might be a good idea to check the fuel pressure while driving too.

 

We have a digital fuel pressure gauge. As long as I can find a Ford adapter I'll run a fuel pressure test. I'll also test for water in the fuel tomorrow. I haven't seen any problems in quite a while, but now that you mention it I remember few years ago we had a few issues with finding 15-25% ethanol in mixtures that where supposed to be 10%.

Maybe I can talk my co-worker into using the power balance test on his Solus.

The power balance test on fords is basically just a real time misfire counter that I can view while test driving correct?

 

Im not sure how it will display on your scanner, on a ford IDS it will show a real time graph and cylinders that missfire will drop down on the graph to a certain percentage depending on the severity of the missfire.

 

looks exactly like this, except this test is for cutting out injectors