Had this truck a few years now, and it has always had a slight miss/hesitation and maybe a few codes. The timing chain skipped a tooth and the truck was down for about a year. I have 4 other trucks, so it wasn't a big deal. I finally had time to put a new oil pump, chains, guides, tensioners, phasers etc. The truck actually runs very well and quiet. But, now misses far more than I remember it doing.

When driving in town constant at 25-30 mph occasionally it will loose power for a brief moment(<1 second) and then be fine, the security light on the dash turns on for a few seconds.

It drives at 55-65 just fine, unless I am going up a hill or something else increasing the load.

2004 5.4 3v 2wd
CEL-
P0453 (fuel tank pressure issue)
P0351 (ignition coil a primary/secondary circuit malfunction)
P0356 (ignition coil f primary/secondary circuit malfunction)

The coil packs are new, and I have injectors on order. But, any thoughts or ideas would be much appreciated.

Also found this thing on the back of the motor, it connects to the fuel rail on the drivers side. No idea where it should go. I looked on my other trucks. But my other 04-4wd has a box by the battery it connects to, but mine doesn't have any of that stuff. And my 08 doesn't have anything like this at all.





And a pix of the truck in question. Thanks again!

 

Well with it being a 2004 when were the plugs last changed? Worn out plugs cause misses

Also in the 3rd pic it looks to have exposed wires going to the COP this with and or bad connection could cause a miss

 

spark plugs were changed within the last 5,000 miles

I do need to put new heat shrink tubing on it. Can't remember why it is like that, but it was doing this before they were like that.

 

Were the COP boots and springs changed when the plugs were changed.

After I changed my plugs because of the OD misfire it came back, changed the COP boots and springs no problems since

STANDARD MOTOR PRODUCTS Part # CPBK240 from Rock Auto is want you want it will be around $25 for the set of 8 shipped to you

 

maybe your problem... looks like somebody spliced a new COP connector on at one point...mite want to do it the correct way..

 

The picture that has the "mystery" thing (red tube) looks to be an extra vacumn port. My 2007 with a 4.6 V8 has one of these. You sure it connects to the fuel rail?

 

Look up on the firewall for the other end of the vacuum

 

Yea, I'm thinking that that looks like it would be a vacuum line to the IWE solenoid if it was a 4wd. It looks and is in the same location as my vac line is that goes to the solenoid. Is it plugged off? Are you sure it goes to a fuel line? The COP connector does look like it was worked on and needs to be corrected. I think your issue or part of it is with that COP connector. Good luck.

 

Yes it goes to the fuel rail on the driver side, sort of.

A vacuum line goes from the fuel rail, to a splitter on the back of the intake. Then there is a vacuum line that goes under the intake, on goes to the brake booster and then one that goes to the IWE. But, apparently in a non 4wd, they still run the line and then just have it capped and let it hang freely in the back of the motor. Weird....

All my cel, cleared up with new injectors. Which is weird because I have no idea how a P035__ code can be an injector. But, who knows.

Truck still shuts off when driving constant at 25-30mph. The security light still comes on, and I've also noticed that I have to turn my cruise ON again to use. But, my radio and all my other "key on" electronics are unaffected

 

With the 453 code have you checked the condition of the fuel control module in back but the spare tire. The aluminum case is know to corrode and cause all sort of fuel related and drivability issues.