It just got cool in the last few days here. This evening I left work and noticed the truck had hardly any power. I had it floored and it was driving like I was using hardly any throttle.

Could it be the EBPV was open? The truck is straight piped so I doubt I'd hear the whooshing air coming out of the EBPV. What else could it be? The wastegate boost line is removed and plugged.

Does the EBPV always open during normal startup (even in warm weather)? Then close as the engine warms up? Or does it only open when the temp drops below a certain point. Could it be that there's another sensor that's going bad?

On the drive home (50 miles) I had the cruise set and the engine sounded like it was accelerating and decellerating on it's own. I was on a flat road, had the cruise set at 69 and I could literally feel myself getting pushed in/out of the seat as it was doing this. I could also hear the engine doing it as well......

Any ideas on this?

Could the feeling I was feeling be the EBPV opening and closing while I was driving?

Today the truck drove EXACTLY like it drove when I first drove it 8 months ago. It only got about 15K on the 6637 air filter and the fuel filter is kind of fresh. BUT, I filled up with some of that awesome ULSD last night! Maybe I have a fuel problem......

I guess I'll see how it goes the rest of the week. I get home too late now to work on it. I'll change the air/fuel filters this weekend to be sure.......


Thanks guys

 

Doubt it is fuel. Would not replace filters unless it is time. The EBPV will only come on when certain parameters are met but will shut off as soon as you go on the brake to shift into drive. Can't really drive that way. So could it be stuck? Maybe. Also, you should be able to hear it louder with a straight pipe or larger exhaust.

I will have to look into surge issues for your driving question.

 

Thanks, Any help is appreciated. I'm completely lost on this one. Funny thing is it drove fine this morning (weather was colder).

I'm going to check the speed sensor on the rear end. That was bad on my F150 and caused the surging while on cruise control. Funny thing is though, the surge thing hasn't happened in awhile. And more I think about, it only happened around 70mph. Once I was up to 75 it would stop. Maybe that sensor is bad. They're not that expensive. I'll see about getting one tomorrow.

 

I'd check your exhaust backpressure sensor first. It controls the EBPV when you give it throttle, sensing high exhaust pressure, and opens the EBPV. If it's bad, or more than likely, the tube going to it from the passenger side exhaust manifold is clogged, it won't sense the pressure and not tell the EBPV to open.

The EBPV will close when you're driving on flat ground, unloaded when it's cold outside. That could likely be causing the sudden and sporatic loss of power you feel while driving.

The EBPV is open most of the time. The truck will cycle it closed and open every time you start the truck, to keep it from getting stuck in the open position. If it's cold outside, it will stay closed to help the engine warm up. Once the coolant reaches a certian temp, or it senses exhaust pressure, it will open. If it opens due to exhaust pressure, and the cooant temp is still low, it will close again once the exhaust pressure drops - when you let off the throttle.

The exhaust backpressure sensor is located on the front of the engine, right in front of the HPOP res, offset about an inch to the passenger side. It's behind the belt. There is a tube running from the bottom of it to the passengerside manifold. My guess is that tube is clogged with soot. Remove the sensor, clean out the tube, clean out the end of the sensor, and reinstall the sensor. I'll bet that fixes the problem of no power when you give it some throttle. However, if it's cold outside, the EBPV may continue to close on occasion when you're cruising on the highway.

 

Thanks JT! Can I spray something inthe tube to clean it? Or is it easy to remove and clean?

So, the EBPV is open during normal driving. I assume open means that it keeps the flow of exhaust in the turbo and exhaust system, closed means it dumps the exhaust out before the turbo back into the exhaust? Do I have that right?

Could I check the function of it by unplugging it? Maybe unplug it and see if the surging goes away?


Thanks again

 

EBPV open normally letting exhaust out the tailpipe when it closes it increases backpressure to warm the engine faster.

The carbon and soot cake on and harden so it is usually a must to remove to really clean it. The sensor comes off with a deep well socket just be sure not to apply any lateral pressure when breaking it loose. It can break and it isnt cheap.

The tube runs from just under the sensor to the passenger side exhaust manafold at the front. A crowfoot wrench works pretty well on the top since it is kinda tight and can be used on lower part also but any wrench will work for the lower.

Best way I have found to clean is spray with Braklean and use 0.95 weedeater line (Square kind) to run down the tube. 3 or 4 rounds with the braklean and line do the trick. Be carefull cleaning the sensor all you need to do is make sure the opening is free from obstructions. There is a diapham about 1/4" deep into the sensor you dont want to damage it.

In the summer when mine was clogged the only thing I noticed was the mileage dropped but when it is warming up now on cold mornings and the EBPV is closed it does rob power

 

In the closed position, it doesn't change where the exhaust comes out of the truck, it just makes the opening smaller after the exhaust pipe. You know how you can close the flue in the chimney to keep more heat in the house and less from going out...it's the same thing that's happening with the EBPV. It closes to create a restriction in the exhaust, which keeps heat in and loads the engine to help it warm up faster. Here are some pics of mine, but off the truck:
Open - https://www.ford-trucks.com/user_gal...108336&width=2
Closed - https://www.ford-trucks.com/user_gal...108335&width=0

Follow Alan's excellent instructions for cleaning it.

You could unplug the EBPV to see if it helps. Default position for the EBPV is open. The plug for the valve is under the intake spider, on the front of the turbo pedistal. It's a two wire plug, with a metal clip on it.

 

John, Mine was doing the same thing last winter, no power under throttle. The line in question was plugged with carbon like the other guy's said, upon further investigation there was a rusted out /cracked place not letting any pressure to the sensor. I purchased a piece of brake line ( I believe 5/16 ) and made myself another line. Works good now, no problems, EBPV shuts off as soon as you put the brake on to put it in gear, just like the other guy's said.

Here is a picture of what you are looking for. Section 11-Engine Electrical , Wiring Harness Front View , #4 Hope this helps
http://www.nav-international.com.br/frame_master.asp?tipo=powerStroke&pg=manual_i/powerStroke/hs.asp

 

Thanks guys. I'll check it out this weekend. So, let me get this right.

It's possible that the tube to the sensor could be plugged, or partially clogged, thus making the truck "think" the engine is just idling, therefore closing the EBPV so it would help it warm up.... Once the tube is open the truck will sense the exhaust pressure and work the EBPV accordingly.

 

You've got it.

 

OK, cool. I guess pressing the brake pedal will make it open back up but then it will close again as soon as the pedal is released??????

 

I don't think the brake has anything to do with the sensor opening and closing. If it's cold enough outside, and the engine oil temp is cold enough, the valve closes. It only opens once either the outside temp warms up, the oil temp gets high enough, or you apply throttle and it senses the increased backpressure. If it's still cold enough outside, and the oil temp is still cold, it will close again once the backpressure decreases - from letting off the thrott.e

 

I beg to differ, pressing the brake does deactivate my EBPV in order for me to drive off without having to push the truck. As soon as I touch the brake the F16 jet sound goes away and I can dirive away. Maybe not as fast as normal but better than with it activated.

 

I couldn't remember, since I have mine on a manual switch. Thanks for the correction Tenn.

 

Alright, here's an update. For the life of me I cannot hear the damn F16 whooshing sound. I doubt it's closing like it should normayy do. My truck sounds normal when it cranks and first runs. it's been cold the last few days and it still sounds normal.

FWIW, My dad's 02 hardly ever makes the whooshing sound. Only time we both know it did it was when we were in Toronto Canada and it was in the teens out.......

I cleaned the sensor and the tube. The sensor wasn't clogged, but it had some crud in there. Tube was fine. i took it off and it blew clean with one shot of brake cleaner.

What else could it be?!?!?!?

This morning I cranked it up. I hadn't ran it since Sat night. It ran rough for awhile (still trying to figure that one out too!) I drove out the neighborhood. Once on the road, I had it floored and it baaaaarely creeped up to 30mph. I mean it was LAME and DEAD!

Then all of a sudden, it took off like a bat out of hell....... It did this less and less until it was up to normal temp......

Who thinks my fan clutch is causing these problems?????????? I going to check it tomorrow and see if it's hard to turn while cold, then check it again once the truck runs right...... we'll see.....