2006 5.4L Intermittent Dead Miss

[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 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.

[Lariat4x485]

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..

Well i had the spark plugs change and the coils. After done that my truck is like new. I have been using it for 3 days now the problem was fixed.

[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.