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James
James, Ford Technician
Category: Ford
Satisfied Customers: 3623
Experience:  Ford Senior Master Tech, Ford gas and diesel expert, ASE Certified
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I have a concerning problem. After rebuilding the entire

Customer Question

I have a concerning problem. After rebuilding the entire front end on my E99 7.3 yesterday, I went out and test drove it. It was hauling ass as usual. Today out of nowhere when I started it up to go to walmart I noticed like zero boost an NO SMOKE white black or blue non at all and I have a straight pipe. Any ideas? The only thing I can think of is, right before I left I pulled and checked every single fuse under hood and dash because I've only had it a year. All were fine though.
Submitted: 1 year ago.
Category: Ford
Customer: replied 1 year ago.
Also I run a blend of Rotella with a little Lucas, it's at level and I change it every 5k. Also, just put in a new fuel filter the other day and checked it just now. clean as a whistle. I also have a cummins and I have never ever seen nor heard of a diesel engine not putting out any smoke at all. I'm talking gas truck smoke.
Customer: replied 1 year ago.
firewall is also nice and clean so it's not a big turbo leak. also unplugged the wastegate and still no smoke or normal power!
Expert:  James replied 1 year ago.

The vehicle is running fine there is just no power? Is this correct?

Customer: replied 1 year ago.
idle is perfect. It just runs like a dog. feels like it has about half the torque as yesterday and no smoke. Wondering if it's something to do with me messing with fuses. I'm a cummins guy and my other truck is older and has no pcm and all that
Customer: replied 1 year ago.
it does shift harder though.
Expert:  James replied 1 year ago.

It will shift harder if it isn't building any boost. If there are no exhaust leaks I would suspect you have faulty map sensor or a restricted map sensor hose. I would also make sure the impeller vanes aren't damaged at all.

Customer: replied 1 year ago.
Aright. Would there happen to be a specific fuse for the map sensor that I could change just in case I overlooked a faulty one?
Customer: replied 1 year ago.
or even a way to just eliminate it
Expert:  James replied 1 year ago.

The only way to eliminate the map sensor is to swap it out with a known good one. Do you have a test light and we can see if it's getting power?

Customer: replied 1 year ago.
I do not. I'm honestly a 1st gen 12valve cummins guy. everything is so much simpler and and powerstrokes are new to me. I did however just go look under the hood. I noticed that a copper line that connects to the bottom of the fuel bowl? (thing the fuel filter goes in) was disconnected. I removed and degreased the map sensor hose, but it was in no way clogged up. The map sensor is oem ford and looks somewhat old so I'm replacing it regardless. Do I have to worry about carbon build up and engine damage while I figure this out? Truck still get up to speed. Also, any other ideas besides the map? Not sure if it matters, but I recently put in a new HPOP and Garett turbo so those are good.
Customer: replied 1 year ago.
What I will do is change all fuses because it is kind of odd that after I checked them my truck runs like crap and hunt down a map sensor tom and get back in touch either way.
Expert:  James replied 1 year ago.

This turbo is fixed. Without the turbo operating this vehicle has trouble just to get up to 25 mph. Since the turbo is fixed the only thing that will affect it are exhaust leaks or air leaks. The map sensor of course. I will try and get the correct diagram for the map sensor. It's been a long day but I believe it gets 5volts from the PCM.

Customer: replied 1 year ago.
Okay. And btw I can actually get up to 60mph or so when I pull out on the highway it just takes way longer. and won't shift till near 3k rpm. I also checked for leaks while under the hood. It's as clean as an 08 under there. I'm in ga so no rust and oil leaks are easy to spot.
Customer: replied 1 year ago.
okay I've already removed and inspected the map sensor. very simple, just don't know how to test. thanks
Customer: replied 1 year ago.
Also I did find an old voltmeter for electronics if that's of any use. Look forward to updates. thanks again
Expert:  James replied 1 year ago.

Make sure all exhaust manifold bolts are loose if they are loose you can lose boost? Is the turbo you used an own replacement?

Customer: replied 1 year ago.
No it is not. it was already installed when I got it, but looks new and worked great. I actually bought this at an auction and have no idea what all is done to it. I just know it was hanging with mustangs out of the hole until this. I went ahead and changed/checked every fuse. Bought + installed a map sensor and greased the already clean connector. When I was at Napa. someone said maybe the truck was tuned and when I pulled and checked all the fuses it reset the computer. Is this possible?
Customer: replied 1 year ago.
Oh and I'm about to double check the manifold bolts now.
Customer: replied 1 year ago.
again to make it perfectly clear the truck ran like an animal 2 days ago then all of a sudden when I messed with the fuses it turned into a chump.
Expert:  James replied 1 year ago.

On this vehicle messing with fuses shouldn't affect power. All sensors are a 5v reference.

Customer: replied 1 year ago.
What else could it possibly be? Including tampering. I'm a college student and everyone seems jealous of my $1900 lifted f3. Also here are some pics of the turbo area if they are of help.
Customer: replied 1 year ago.
This is the only area with any sort of oil but everything is tight.
Customer: replied 1 year ago.
Third pic
Customer: replied 1 year ago.
Also just noticed it has burned 1/4 today and I've only driven to napa and a few test drives down the street
Expert:  James replied 1 year ago.

I don't see anything wrong with any of the photos. Are all charge air cooled tubes still in tact and tight?

Customer: replied 1 year ago.
Oh yeah I've been at it all day. Quadruple checked EVERYTHING. The 3 other things I thought to check was the the fuel, and honestly the fuel in my powerstroke has a very slight hint of gasoline compared to my cummins. I'm going to top it off in the morning to dilute just in case some got in there somehow. Another is the pigtail connecting to my new MAP. Any ideas on checking the pigtail to make sure it's powered? Again, all fuses are good though. Third are there any other sensors around the turbo area that could cause this thing to not smoke and lose power?
Expert:  James replied 1 year ago.

The only way to test the wires is with a multi meter. If you had a scan tool to monitor manifold pressure to see how much boost is actual building. Low fuel pressure can cause this concern.

Customer: replied 1 year ago.
Would it be possible that I just have a bad fuel pump? It's a stock one, the truck is not and I was kind of ripping on it playing around after I fixed the front end. The pump looks like it may be the original and the truck has 267K.
Expert:  James replied 1 year ago.

It very well can be producing low fuel pressure so it seems like the turbo isn't working correctly.

Customer: replied 1 year ago.
I think I figured out the problem. Because the truck was blowing big clouds of black smoke it must have been programmed. I'm assuming now that it reset when I changed the fuses back to stock and this is just how a normal 7.3 is supposed to run.
Expert:  James replied 1 year ago.

That can do it. If you were unaware of it had a programmer installed ever it very well could be the issue.

Expert:  James replied 1 year ago.

You want a excellent 5 star answer & I would like to be rated the same for providing it. Consider I don't know your skill level & I can't see, smell, hear, or touch the vehicle. It may take a few back and forth replies. Try your best to respond with good detail so I can do the same. A rating is required. Your rating me, what I type. I am not an employee of this website, nor have control over the fees or the time it took to get a response. If you rate negative or not at all you still paid, but I get nothing. I want you pleased with me and my efforts, so let me know if your experience here has come up short.