Newb here from Cincinnati. Picked up a very basic 2006 F250 2wd XL single cab a few weeks back. It seemed to run great and had no CEL. I drove it to Columbus (1.5 hours each way) to pick some wheels up for my other vehicle and the truck started missing pretty badly. I now have a CEL and the truck barely runs. Barely made it home.

It's strange because if I start the truck when cold it starts and runs fine, but once it warms up it starts to run really rough. After it starts running poorly the more throttle you give it the quicker it will die. While I was limping it home if I shut the truck off and started it back up it would run ok temporarily, but starting missing really bad again. I'm going to attempt to limp it to an auto parts store today to see what codes show up.

I was told the truck had some "fuel work" done before I bought it, but I have no idea what that included. I'm going to start with the basics and start pulling coils and plugs to see what they look like.

Are the Motorcraft SP-515 plugs the correct plugs for this truck? It seems like it's somewhat hard to find the right parts for the 3v V10's.

Any other tips would be greatly appreciated!

 

Definitely check the plugs. And clean the MAF - the telling indicator here is that it runs fine when first started, but once it warms up enough to enter closed-loop, it falls on it's face.

Check the codes though, without those, it's all just guess-work.

 

On the MAF, what am I looking for exactly? I know that may sound stupid, but I pulled the MAF last night and the piece that is inside the MAF tube looks spotless. I've seen older MAF's that had a screen on them and those would get dirty sometimes. I guess that's what I was expecting.

It looks like someone replaced the air filter recently as well.

Somehow the battery was COMPLETELY dead so it's sitting on the trickle charger today. It was weird because when I first turned the key it cranked once or twice, but after that I wasn't even getting any clicking at the starter. The headlights and blower motor worked fine though.

I checked out a couple of the coil packs and they have definitely been replaced at some point. They are no name brand. I found a part number, but no other identification. I removed the cylinder 1 coilpack and started to take a plug out, but I really want to wait until I can start the truck and get it warm before starting to remove the plugs.

More to come tonight.

 

Well, if it's completely clean, then leave it

 

My money is on the COP's... replace them with OEM Ford units. Not cheap but a lot of the aftermarket ones are known to have issues.

 

You'll have a hard time trouble shooting anything if the battery is bad and signal voltages are out of spec.

 

I would add to the basics list check fuel pressure.
A clogged filter could cause fuel starvation at higher RPM.

 

Battery tested fine yesterday. 12.7 volts and 800cca's. Makes sense because it took a full charge and all of the dash lights, headlights, blower fan, etc all work fine. I took all terminals off and wire brushed some crud off of them. Same result. I think the starter took a dump on me. I'm not surprised as I really had to work the starter when I limped the car home before parking it.

 

The fuel filter was replaced just before I bought the truck. I'll have to take a picture but something on the fuel rail right behind the MAF looks brand new also.

 

That's probably a fuel pressure regulator.
What is the code that set your CEL light?
Amazon has a basic code reader for $15 - Oxgord CAN OBD II scanner Tool.

 

Borrowing a scan tool from a friend tomorrow. Will know more in the next few days once I get the starter replaced.

 

I was able to get the starter replaced tonight. That was the no start issue as the truck fired right up. Old one was a Visteon brand so I don't think it was OEM. I put a TYC in it. Hopefully it lasts me a while.

Edit: After a little more digging maybe the Visteon was OEM?

Anyway the truck fired right up and ran perfect for about 20 minutes at idle. I took it around the block and initially the truck ran perfect. After about 10 minutes into the drive I could begin to feel a hesitation, but the truck still ran decent. It wasn't missing at all like it was before.

I pulled it back into the driveway and hooked up the scanner. I got 3 codes:

-P0420 - Catalyst system efficiency below threshold bank 1
-P0191 - Fuel Rail pressure sensor a circuit
-U1900 - ABS

One thing I did notice is that on the driver side of the fuel rail there is a sensor that I mentioned above that looks much newer than the engine:



Bad converter maybe?

 

I would suggest checking your fuel pressure first. If there is something wrong with your fuel pressure it could cause your cat to read bad.

Here is a video I made a while back to check your fuel pressure. Your truck should respond like mine, otherwise you have a fuel problem.

 

Do you have it documented anywhere how you setup the gauge? Where you sourced the fuel feed from?

What ended up being your issue? Or was there one at all?

 

There was no issue... I was having a pinging noise which I thought originally maybe fuel pressure was low and I could be running lean. After tearing down my engine due to a bad spark plug blowout that couldn't be repaired I found a ton of carbon in the cylinders. This was my cause.

The fuel pressure in my video is normal and how it acts on a good working V10.

Just go down to an auto parts store (Napa, Autozone, Oriellys, Sears, etc) and ask for a fuel pressure gauge or oil pressure gauge (oil pressure gauge is WAY more expensive). I think it set me back like $30. You don't hook up the power, just use the hose and hook it into your fuel rail. There should be a spot to plug the hose into with an adapter.

I had a vacuum gauge in my toolbox and the connector for that worked perfect to fit my fuel rail fitting.

Equus 8362 - Fuel Level Gauge | O'Reilly Auto Parts

Otherwise you could get a fuel pressure tester if you don't mind ordering/waiting and not have to retrofit a connector and gauge. Notice the brass fittings on that tool, that's what you need and would be the easiest way. You might be able to take that picture into a local auto parts store and have them find you one.

Save on OTC 5630 Fuel Pressure Tester Kit at ToolPan.com

I went with the gauge because I could route the hose into the cab of my truck and drive around and verify fuel pressure. Otherwise you are limited to only checking the pressure with the hood open and in park. You could blip the throttle cable though to see if the fuel pressure rises.

Good Luck!