TOPIC: 6.8L V10, 2004 Ford Excursion

I have had the Groove for a few months now. I must be missing something because I have only been losing fuel economy.

The engine has multiple vacuums connecting behind throttle body:

* The largest one is the PCV which I have capped off at the throttle body; Question: Will it make any difference if the PCV valve on the valve cover is blocked off or open as long as the vacuum side is plugged?

* The second one goes to the brake power booster, so I dont know that I can plug that off.
* The last one I am not sure what it does.

Please can anyone who has or has worked on a Ford V10 help me get this figured out?

Thank you!

Dan, if you want to have a few people know who you are and what you're working on, it is best to make a good post to the Welcome Mat. All persons who have previously posted there.

Don't gauge your post by the others before you. Take some time, as we are Family first here, but know nothing about you yet!

Now, the only thing needed is to stop the flow through the PCV Valve and into the intake manifold. Ignore the other connections, other than to inspect them to ensure they're not leaking. If you have a question about a line's integrity, replace it.

Hope this helps!

Ron

Dan Flynn wrote: * The largest one is the PCV which I have capped off at the throttle body; Question: Will it make any difference if the PCV valve on the valve cover is blocked off or open as long as the vacuum side is plugged?

* The second one goes to the brake power booster, so I dont know that I can plug that off.
* The last one I am not sure what it does.

Please can anyone who has or has worked on a Ford V10 help me get this figured out?

Thank you!

Once we've got your truck doing what it should, we hope you'll head over to the Welcome Mat as Ron has suggested. I find I get to know people a bit better by working with them, and then finding out where they come to the family from, so I'll be a bit more direct in answering you, Dan- Sometimes if you want to get the gains, you've got to work a bit harder to find the roadblocks and then dismantle them to clear your path ahead first.

Capping the PCV at the vacuum source as you have is the preferred method.
You should NOT remove vacuum from your brake booster, or you're going to have problems stopping.
you should track down #3...just so you can determine if removing it from the vacuum source is a good idea or not. (I suspect it's part of the Evap system, and if I'm right, that needs to be there too)

what else have you done to the truck, other than plugging the PCV and getting the TB grooved? Have you opened up the spark plug gaps?
is your check engine light on? if so- what do those codes say? Do you have a code reader?

We're big on maintaining the vacuum produced in the intake as much as possible around here, so as long as you're sure you don't have a leak somewhere, we have to start looking at other things.
You come here looking for help, so here is my checklist of things to look at.

The first I like to look at is Engine coolant temperature - is the truck getting up to proper operating temp, and triggering the computer to go into closed loop, where it listens to the upstream oxygen sensors to adjust fuel delivery during operation? is there enough coolant (and no air) in the cooling system/radiator?

Are the oxygen sensors working correctly? if the groove is working SO well that those sensors are seeing so much more oxygen in your exhaust than the computer expects, it starts delivering more fuel to the cylinders...or you could have an exhaust leak, which brings outside air into the exhaust causing the same condition...or possibly sticky valves, which cause outside air to be sucked into the exhaust and past the sensors, confusing them (again) with more oxygen than the computer thinks. Then there's the EGR system - if that valve is stuck open, engine vacuum is drawing outside air into the exhaust past the oxygen sensors, who see the extra oxygen and make the computer think it's not delivering enough fuel

Have you cleaned your MAF sensor recently? If that is giving incorrect readings, you'll also get the computer deciding to use more fuel to protect the engine.
You're not, by chance, using a K&N or similar reusable air filter, are you? If so, is it in the factory air box, or is the filter exposed in the engine bay?
What does the exhaust smell like when it's up to operating temperature?

Happy Saturday - there's your "Honey Do" list - tell your wife/girlfriend I'm sorry