2006 5.4L Intermittent Dead Miss

[bskouby]

Hey all, I posted this over at F150online, but I thought someone over here might have some insight into this. I am gryphon custom tuned, so there could be something I am missing here. This is what I posted:

------------

I'm having an intermittent issue with my 06 FX4 5.4L that I thought someone might be able to shed some light on. Some background about the truck first.

It is Gryphon tuned (custom 87 performance and tow tunes)
No CAI, stock filter
True duals, no mufflers, maggie X pipe, stock cats
47,000 miles
plugs changed around 44,000 with replacement motorcrafts (SP507 I think, but I cannot remember right off the top of my head).
new motorcraft COPs

Last spring/summer I started noticing a hesitation/lugging/slight miss at about 45-50 MPH. This issue NEVER threw a CEL or stored a code. This issue would repeat in stock tunes, canned tunes, and gryphon custom tunes. After doing some research on this board, I concluded that I probably had a bad plug and/or COP. Since I had no idea what cylinder the "misfire" occurred on, I just figured it was best to replace the plugs and COPs.

I ended up breaking off two plugs (cylinders 1 and 8) but was able to extract using the Lisle tool. The plugs looked OK. After putting the truck back together, everything ran great. That is, until recently.

For the last few weeks, the truck would intermittently start having a "dead miss". This normally occurs when the truck is at full operating temperature. Sometimes it will happen at speed, sometimes it will happen when idling at full stop. Many times when the miss starts, I can lift off the accelerator and get back on it to clear the issue. Sometimes it will continue to miss until I shut the truck down and restart.

My first though was the tunes. I reset back to stock and ran a couple tanks of gas through. No issues. I then switched back to tranny tune only, and ran for a while. No issues. I then loaded up the performance tune, which behaved for some time (probably at least 300 miles) and then it started missing intermittently again. I loaded the custom tow tune, same issue.

Even though the problem shows up when tunes are loaded, I don't think it is a problem with the tunes themselves. I *think* I still have a problem with either plugs, COPs, or injectors. I also think that the tune is just aggressive enough on timing or fuel/air to make this problem surface.

I'm still not getting a CEL or a stored code when this is happening, so I cannot narrow it down to a cylinder or bank. The only thing I haven't tried is loading the canned tunes. I'm not sure this is really necessary, but for testing purposes I probably should.

Any ideas what to look for? Should I pull the plugs one by one and check them out? Could we be looking at an injector sticking closed? What I find weird is that I can drive for literal days and weeks without any bad behavior, and then one day I have several instances in a single day.

And it is a true miss. The exhaust note gets real flat, truck starts to shake. Oh...and finally....the fuel economy completely sucks. However, the fuel economy always sucked on this truck, and it is winter here.

Any insight would be appreciated. This truck runs like a raped ape 98% of the time. It is just the other 2% that is really annoying me.

Thanks!

----------

Also, I pulled and cleaned my MAF using the CRC electrical contact cleaner spray this past weekend. I did notice that there was a bit of a clear oil like substance all over the MAF housing. I do not run an oil impregnated filter, but it is possible the previous owner did though (I bought it used at about 30K).

I also replaced the fuel filter. The filter looked original, and the fuel I poured out of the filter was slightly darker than normal, but not bad overall.

The truck does run/idle smoother than before, but it did not correct the "dead miss" issue. I still don't get a CEL, so I cannot narrow it down to a cylinder or bank. I'm planning on pulling the COPs and plugs this coming weekend and see if I can spot anything out of the ordinary.

The issue still only surfaces when under tune. If I run stock or the tranny only tune, it will not miss. This still leads me to believe that there is a weak point somewhere, and the tune is pushing it over the limit. I am going to check for a cracked insulator on my plugs, and take a close look at the COPs. I am running motorcraft COPs, and I have the 8 original COPs sitting on my work bench.

The miss does seem to start under load at right around 45 when the truck shifts into OD. This is why I originally changed the plugs and COPs earlier to address this issue. However, the issue has worsened now and will miss even at idle (however, it has never to my knowledge started missing at idle, it is usually after missing at load first).

Any other thoughts out there? Anything I can look for this coming weekend? I'm also leaning towards an intermittent injector fault, but not sure how I can check for that.

[88Racing]

You might want to check the connectors to the cops to make sure they are fastened correctly...
Cop boot springs are installed correctly...
Not to much dielectric grease on the cop boots....

[Lariat4x485]

I have been having the same problem. At about 55 - 60 mph my truck starts shaking, engine light turns on. After that i read the dtc, I had 2 trouble codes. The first one said Cylinder 8 Misfire and the second that there was an error reading the trucks computer. I cleand my air filter, change fuel filter and tomorrow im changing the spark plugs and the connector. Any helpfull info what might be wrong???? Thanks in advance..

[bskouby]

Originally Posted by 88Racing

You might want to check the connectors to the cops to make sure they are fastened correctly...
Cop boot springs are installed correctly...
Not to much dielectric grease on the cop boots....

Yup, all that is part of the plan. I'm going to pull all of COPs, clean the boots AND springs of any dielectric grease, and then re-grease them.

I will probably pull the plugs and check for cracked insulators or other suspicious things. It would be nice to narrow this down to a cylinder if possible. Not getting a CEL and codes is making this hard to track down. And if I cannot get this tracked down soon, I will have to detune this bad boy so I can be sure my wife can drive it without it giving her any trouble. After a Grypon tune these things are total slugs in stock trim.

[bskouby]

Originally Posted by Lariat4x485

I have been having the same problem. At about 55 - 60 mph my truck starts shaking, engine light turns on. After that i read the dtc, I had 2 trouble codes. The first one said Cylinder 8 Misfire and the second that there was an error reading the trucks computer. I cleand my air filter, change fuel filter and tomorrow im changing the spark plugs and the connector. Any helpfull info what might be wrong???? Thanks in advance..

Man, I wish I could get a CEL to help track this down. Anyway....

If you are changing the plugs, and this is on an 04 up to an 2007/early 2008 (I cannot remember the exact cut off) 5.4L 3V you need to be sure to take extra care when changing the plugs. Just do a search for the 5.4L 3V spark plug threads here and at F150online, you will find tons of information. Be prepared for broken plugs, heart stopping moments, and a bunch of busted knuckles.

If you have a 4.6 I don't think you have any worries, well, other than the busted knuckles.

[88Racing]

Originally Posted by Lariat4x485

I have been having the same problem. At about 55 - 60 mph my truck starts shaking, engine light turns on. After that i read the dtc, I had 2 trouble codes. The first one said Cylinder 8 Misfire and the second that there was an error reading the trucks computer. I cleand my air filter, change fuel filter and tomorrow im changing the spark plugs and the connector. Any helpfull info what might be wrong???? Thanks in advance..

What motor and year of truck?

[88Racing]

Cheap place to get cops is on eBay......look for global store and the part for the 5.4 3V is DG511....I think....
http://cgi.ebay.com/ebaymotors/NEW-I...Q5fAccessories

[Lariat4x485]

My truck is 2006 f 150 5.4 engine

[bskouby]

I've decided that I am going to do the following this weekend.

1. Pull and check all of the plugs for damage/di-electric grease in the wrong spots.
2. Clean and re-grease the COPs and boots.
3. Pull and check the CAM position sensors.
4. Pull and visually inspect the VCT solenoids for any damage.
5. Check and and clean fuel injector rail connectors.

If I find any issues I will replace/repair and then test drive. If the problem is still present I will do the following:

1. Return truck to stock tune
2. Confirm that the problem is not present on stock tune (which it has not been since I replaced the plugs/COPs).
3. Update the gryphon via pegasus and load up the canned tunes.
4. Flash my truck with the canned 87 tow tune. Test.
5. Not sure what my next step would be. If the canned tune is fine, I would suspect something up with the custom tune. Perhaps this: http://forum.gopowerhungry.com/gryph...esitation.html

I guess the next logical step after that would be to open a support case with PHP and see what they say.

[lbjailer]

welcome to the club. 08 Screw 5.4L same issue. Only 17 thousand miles so it isn't plugs or dirty intake. Gryphon works fine on canned tunes, its the custom 87 tow tune that causes my isue.