What are vgt, ebp, map reading?


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Check/replace the "crummy" VGT pigtail (6E7Z-12A690-DA) and make sure the MAP hose is not deteriorated and that you plugged it back into the manifold on the passenger side.

 

Does your vgt sweep at idle or did you give it time to relearn? Could be sticky vanes worth a shot to pull and check turbo. Interested to see what you find, mine just did something similar pulling my camper. I changed my tune and so far hasn't done it again but I am thinking it is just coincidence. From what I read it seemed sticking vanes was most common.

 

As far as VGT "Sweep goes".......I don't think it's doing it right now. How do I "relearn" that? I've put 30 miles or so on the truck....does it need longer than that?

I went back to the "stock" tune before I fired up the truck for the first time.....so it's probably trying to work the EGR valve, even though I have an EGR delete kit on the truck now. One thing I might do it load one of my custom tunes with the EGR turned off....see if that cures the problem.

The EGR valve itself was pretty nasty and gunked up.

I'll do some troubleshooting and have some good numbers and data for you later tonight.

I really appreciate all the help!!!! :smile2:

 

Search vgt re-learn it is on page 3 post 29, not sure how to link it here.

 

IIRC, the VGT relearn is only applicable to Early 03 engines. Not sure what the OP has.

 

Mine is an 05'.

 

***UPDATE***

OK.....here is what I found out.....it just confuses me more. Maybe it IS the EBP sensor??

So I went out to the shop and turned the key on and let my Torque App on my phone sync with the bluetooth ODBIII dongle so I could read all of the PID's.

With key on, engine off.....here is what I'm getting. MAP: .1, EBP 14.2, VGT 0.0, and I was showing a P0299 (turbo underboost) and P2262 (turbo boost not detected) faults.

I fired up the truck, it started right up......but instantly I noticed that I didn't have that typical turbo whistle coming from the exhaust....it just sounded rumbly, with no turbo whistle at all. I fiddled around around with the EGR and VGT plugs while it was idling....no change. Went around and moved all of the wiring around....no change.

With the engine cold and idling....this is what I got. MAP: -.1, EBP was at 40 but then dropped to around 15, VGT was up at 85% (which it always does since I don't have a muffler or cat).

So I let it warm up, and took it for a drive. Same as before. NO power, I could only get around 10psi MAP (boost), and the VGT was moving around between 40-60%. NO power, and just a hint of turbo wine. It wasn't blowing any white or black smoke...just no power. The one strange thing I noticed is that the gauge on the dash stayed about at 0-1, even with the MAP was at 10psi....strange.

So I get home.......and let it idle for a little bit. The VGT is around 67%, EBP is 16.5, and MAP is around 0-.1.

I turn the key off for a second or two, turn it right back on.....fires up, instant turbo whistle out of the exhaust, everything seems normal again. The other strange thing that happened is that as soon as I fired it up, all of my PID's on my Torque App said NO DATA...not sure why. I turned the truck off, and back on...then the PID data all came back. I cleared the PCM faults, and I go take it for a ride.....it's all back to normal!! Good boost, great power, the dash boost gauge is working now....perfect! That's the exact same thing it did the other day. Runs like crap, no boost, warm it up really good, turn it off, back on...and it's all back to normal.

I get back to the house.....no codes, everything is fine. I let it idle and EBP is now at 40, 1.0 MAP, 65 VGT, 22.8 IPR, 580 HPOP....everything perfect!!!!

So what the hell happens when I turn the key off for a second?? What's the EBP supposed to be at idle?? Why would it read 15 at idle, and then 40? This is driving me nuts!!

Could it have something to do with me getting it out and running it to heat up the exhaust...and that does something to the EBP sensor to make it start working as soon as I turn the key off and restart the truck?? It's definitely not a leak, it's something electrical.

Ideas?

 

EBP, MAP, and Barometric should all be about the same koeo. Idling the ebp will be higher. MAP should be baro+boost. 14.6 sounds about right for koeo. MAP should be the same tho. 1.0 for MAP is wierd. Check to make sure you are reading psi in the settings.


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You should not be at 40 psi EBP at idle. Ever.
Did you check the MAP hose and connection? Did you verify that the nipple on the intake is not clogged? Have you checked the IAT2 sensor on the drivers side of the intake manifold? Have you checked the EBP tube to see if it was clogged? Did you replace or repair the "crummy" VGT pigtail?

You may very well have a harness problem, but you are not freely giving information that I and others have asked for.

 

You should not be at 40 psi EBP at idle. Ever.

Unless you are reading from an SCT Livewire




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^^Good point. I forget that all data given in various posts may not be true data. Only what the method invoked gives. I'll defer on that point. Still think we're missing some important information though.

 

Well, it fired up this morning just fine....and ran great. Not sure if the problem was the EBP sensor or not. The only other thing I did to it was load up an SCT tune file that turned off the EGR valve.

I guess I will drive it for a few days and see how it does.

 

Well I'm late to the party but had the same thing happen to are Excursion...It was the EBP sensor there like 120$ at ford and its been running fine every since...The boost thing was crazy just like you said at the start of the thread..
would read neg boost #'s then go to like 25 to 30 pounds crazy

 

@iqraceworks is everything still good after cleaning your eb sensor and tube?

 

So far so good. I've driven the truck to work every day this week and haven't had a single problem.

I think before I'm going to assume it's fixed, I'm going to switch back to the stock tune and run it for a week. If it acts up on the stock tune, I'm going to say it's either an egr valve issue (SCT tune turns egr off), or maybe the stock tune looks at the EBP sensor, and the SCT tune doesn't??

I will report back what I find.

 

***UPDATE***


Well....I ran the truck all week long, every day I drove it to work and all around town. No issues...ran perfect, no fault codes....ran perfect!! This was all after cleaning the EBP sensor...AND running on a canned SCT street tune with the EGR turned off.

So tonight after I get home from work I figured I would switch back to the stock tune just to see what happened. Well, it fired right up and seemed to run good....but when I scanned for fault codes....I'm back to getting the PO299 low boost fault.

So now I'm stumped.....what would it run fine on a tune, but throw a P0299 code on the stock tune? I'm guessing that tomorrow morning when I fire it up, it's going to have that low boost issues again.

So what does the stock tune monitor that the SCT tunes don't? This is very frustrating!!

One thing I did notice is that with the SCT tune, it always idles at 85% VGT...I'm assuming that's to get the turbo whine sound out of the exhaust. When I went back to the stock tune, it stayed on 15% for a long time, then started doing it's sweeping thing.

At this point....I don't even know where to start. Ideas??

 

When i had an ebp/map correlation issue, my vgt was at .15. Even when my aftermarket sensor was reading close to right. Something in that loop is not jiving. Unplug the ebp, and it should read 21.48 default. Odd how a rune changes it though.


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When the key is on and motor is not running....the ebp sensor is showing 14.4 psi (atmospheric). When I unplug it, it's showing 6.3psi (14.4+6.3= 20.7). Does that sound right?? When it's idleing with the stock tune, the VGT % is always moving all over the place...15% then 40% then 70% then back to 15%...but with any SCT tune....it's pretty much always pegged at 85%.

Any ideas??

 

One other thing I just got while running the stock tune was a "low exhaust back pressure" fault. I think tomorrow I'm going to replace the EBP sensor....just to take that out of the equation.