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Early 99 Turbo/Waste Gate Problem

9K views 12 replies 3 participants last post by  pif_sonic 
#1 ·
I am new to this site and hope someone can give me a little help or maybe they have experienced the same thing.

I have an early 99 F-350 Crew Cab, 7.3L, 6 spd manual transmission. I have an Edge Tuner installed. The things I will describe happen on all 5 settings and in “Stock” mode. Two things are happening that I am a little uncertain about.

1- At a low throttle, in 2nd or 3rd gear, around town I hear a hissing sound from the Turbo and then I look at the boost gauge, it will go from approximately 2.2 psi to 0 psi. As soon as I get back on the throttle the boost will jump back to 2.2 or a little higher depending on how much I get on the throttle. If the boost gauge is at 0 psi and I add throttle very slowly I can keep the boost at 0 psi all the way to 2000 rpm.

2- If I have the pickup on cruise at approximately 65-70 mph, with no load, and the boost gauge reads 6.0 psi it will drop to approximately 5.3 psi -5.5 psi and then go to 6.2 psi -6.3 psi and then settle back to 6.0 psi and start all over again. When the pickup is doing this you can feel it surging. If it stays above or below 6.0 psi it seems to work just fine. If I am pulling my 32 foot fifth wheel the pickup acts like there is no problem at all. If I have it on cruise with the fifth wheel it will range form 8.0 psi to 12.0 psi on the boost, depending on wind, grade of the road, ect. No problems at all, no surging.


Fuel mileage is 14 mpg -18 mpg depending on how I drive while empty. Fuel mileage while pulling the fifth wheel is 10.0 mpg – 12.0 mpg. I took the vehicle to a local mechanic and he said it was a sensor that cost $186 plus labor. He also added that this may not be the problem and this was the place to start. I have not changed the sensor yet, was looking for some input from you guys first.

Thanks in advance for all your help.
 
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#2 ·
First thing to check is all the boots on the intake tubing make sure they are not loos or cracked. If all of that checks out i would look at the up pipes from the exhaust manafold to the turbo.

What sensor did he say to replace?

And prepare youre self to take some crap about the edge.
 
#3 ·
All that looks good it was already checked. I can’t remember which sensor it was but I will find out today. I will also get the codes that came up when he checked everything.

I have thick skin, I can take it about the Edge. I have no complaints so far. The only thing I want to do now is upgrade the air filter system, still working on which one to buy. I already did the exhaust.

Thanks again for all the help.
 
#4 · (Edited)
#6 ·
most likely it has to do with the exhaust backpressure sensor, its located on the front of your engine block, its not the icp, its not a fuel issue, your sensor and its tube that runs off of the right side manifold are clogged with soot and it is giving false readings of having too much backpressure and is cutting your boost. look on dfuser.com and a sensor eliminator can be purchased for much less then the cost of the sensor and tube. go to google and type in exhaust backpressure sensor and it will give you all the info you need to educate yourself.
is it showing any p0476 or p0478 codes?
 
#8 ·
I just pulled mine yesterday. Not a bad job just tight. Becarfull I broke my sensor off in the bracket. I had to pull the bracket and drill and tap for the new one witch ran me $100.00. I just wanted to clean it. I did not pull it for youre symptoms i pulled it for fuel milage. I am only getting about 13MPG my 99 got 18MPG. It was chock full of soot all the way into the sensor. I dont think i could have cleaned it with out reaplacing it any way. Some get away with just cleaning.
 
#9 ·
Can someone post a couple pics of the sensor, the tube and whatever else needs cleaned regarding the exhaust backpressure sensor?? Also I'm new to how the Power Strokes work and what makes them run the best. Can anyone tel me why the exhaust backpressure issue will effect the mpg???? Thakns agian in advance.
 
#11 ·
Truck went to the shop today. I was told the truck passed every test and it gave no codes. Now I'm really getting upset. The next thing I am going to do is unplug the Edge and see if the symptoms continue and then re-test.

Does any body know if there is an updated program for the Edge. I know, I was informed I may get a little flack about the Edge, that's OK, I'm ready.

Thanks again for all your help.
 
#12 ·
Power hungery performance.
The owner of power hungery performance desighned the edge under Edge guidlines. Well he is the only person licensed and has the capability to tune the Edge. He can put custom tunes on youre Edge. So you will not have off the shelf crap any more you will have proper tuning done spacifacaly for youre needs and truck set up.
 
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