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  #1  
Old 07-29-2014, 04:20 PM
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Boost Issues

I made a couple of posts in someone elses thread but didnt want to hijack it too bad so I am starting a new one.

My truck is not producing as much boost as it used to and the turbo seems to lag more than it used to on initial acceleration. I am also seeing (much) more black smoke if I try to accelerate hard from a stop and occasionally I see a puff of smoke when I try to accelerate at highway speeds. I am also starting to notice more of a rumble sound from the exhaust instead of the jet fighter/blow drier hybrid sound that I am used to. Under normal driving conditions (normal for everyone else) I probably would not even notice the differences but the way I drive I can certainly tell the difference.

The first thing I though were sticking vanes in the VGT. I took it apart over the weekend and gave it a good cleaning. There was virtually no rust and very little carbon/soot buildup - just enough to get my hands really dirty but not enough to cause anything to bind. All of the parts looked good - unison ring was not worn, vanes would freely move but were not sloppy, bearings felt fine, etc. I got it all cleaned up and back together but it didnt really make a difference.

I am able to hook my AE up to the truck to cycle the VGT and I can hear the pitch of the turbo change so I know it is working (at least partially) and responding to commands from the ECM. Today I added a few more PIDs to my Scan Gauge (EBP, VGT, and MAP) so I could easily watch the numbers as I drove around. KOEO EBP and MAP are within .5 psi. KOER at idle the MAP is about 15 - 15.5 psi and the EBP is about 17 - 18 psi. Driving the EBP would climb up to about 50 psi but I never saw it go over that. VGT never did go outside of the 15% - 85% range - from what I could tell it usually stayed in the 40-50% except when I would go WOT or back to idle and it would go up or down. Boost gauge (OEM in the dash) is not going above 22-24 psi where it used to hit 28-30 easily. It is also slowly droping to about 20 psi as RPMs increase, when the truck shifts into the next gear they will climb back up and drop again as RPMs climb. I am also noticing that EGTs do not seem to be quite as high as they used to be - under heavy load, like merging into interstate traffic, it was not that uncommon for EGTs to get in the 1350-1400 range for a few seconds until I let off. Now they seem to be staying in the 1100 - 1200 range under the same heavy load.

About the only thing I have not done is pressure tested the charge air system. I plan on doing that this weekend but I am not sure if that will be the issue. I can see where it would cause the slow boost/low boost issue but would it cause the rumble I am hearing in the exhaust at idle? I am leaning toward the VGT actuator/solenoid purely because of the different sound at idle and the fact that I have already cleaned the turbo and the vanes did not appear to be sticking.

About the truck: 2006 F250, 170k miles, 4x4, automatic transmission, 4" turbo back AFE exhaust, EGR delete, Atlas 40 FICM tune, 58v FICM upgrade, SCT canned performance tune (I know, I have already paid for a custom tune but I want to get this issue resolved before I flash it).

If anyone has any suggestions I am more than willing to try them! I dont like the idea of throwing parts at something until it gets fixed. I certainly dont like that idea when we are talking about $900+ turbos!

Also, sorry for the long post but I am trying to give as much information as possible right from the start.

Last edited by BrianSnelgrove; 07-29-2014 at 04:24 PM.
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  #2  
Old 07-29-2014, 04:45 PM
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Good post with some good preliminary diagnostics on there. Sounds like you've done some research on this before.

Your issue does sound like a turbo/boost issue. It hasn't logged any codes? What does KOEO and KOER test do? Does it log any codes after the test?

Normally black smoking is caused by turbo or EGR issues. Seeing as you have an EGR delete it can't be something with that. Off the top of my head it sounds like a possible issue with the EBP sensor. Have you pulled the sensor and blown through the tube? I've seen some goofy boost issues caused by a plugged up EBP sensor tube.

Pressure testing the intake side isn't a bad idea either though. Have you inspected the exhaust side turbo Y pipes and made sure you don"t of't have any sort of leaks there?
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Old 07-29-2014, 05:38 PM
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I've had this 6.0 four about 4 years, I've researched all kinds of issues!

When I had the turbo off last weekend the only soot residue was on the downpipe and it was a very small amount. i didn't see any soot on the firewall, uppipe, or the connection between the uppipe and turbo. While I have not pulled the EBP tube off yetI don't know if that is the problem, the scan gauge shows a quick PSI change as I accelerate and decelerate but I will certainly pull it off and check it.

The only codes i saw were FICM performance codes. I think those are related to the 58v FICM so i was not really concerned about them. I haven't run the KOEO or KOER tests yet but I will and post the results.
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Old 07-29-2014, 06:19 PM
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The only code before the KOEO/KOER test is P0611 - FICM Performance. I reset the codes and ran both the KOEO and KOER tests. KOEO brought the P0611 back. KOER found P1703 - Brake Switch Out Of Test Range.

I brought up the data meter in AE and started looking at the EBP. EBP Absolute is about 20 psi but desired is about 5 psi - they are fluctuating slightly - and the VGT duty cycle is about 77%. Does that sound right? Is either AE or the ECM adjusting for barometric pressure in the desired EBP?

If I let the truck sit and idle for a few minutes and sometimes the VGT duty cycle slowly climbs up to 85% while other times it hovers around 66%. I can cycle the VGT using AE and there is definitely a difference in the sound of the exhaust and the EBP drops slightly.
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Old 07-29-2014, 11:49 PM
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Your engines breathing

Lets see if I can keep this simple. When you are talking about boost your talking about how your engine is breathing. It inhales and exhales just like you do.

To do that the pcm compares several sensors not just one. Inhale it compares Mass air flow; Map;Iat. Exhale is EBP. It compares all of these to tell the VGT what to do, whether to breathe faster or slower to give the right oxygen content to support the combustion process.

You may have COPD or double phnumonia.
EBP issues can be a biased sensor, plugged tube or actual restriction in the exhaust system. If your system is too restricted the engine can't exhale and it will smother and die.

You need to determine which one is doing what.
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Old 07-30-2014, 03:03 PM
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Quote:
Originally Posted by dannyboy950 View Post
Lets see if I can keep this simple. When you are talking about boost your talking about how your engine is breathing. It inhales and exhales just like you do.

To do that the pcm compares several sensors not just one. Inhale it compares Mass air flow; Map;Iat. Exhale is EBP. It compares all of these to tell the VGT what to do, whether to breathe faster or slower to give the right oxygen content to support the combustion process.

You may have COPD or double phnumonia.
EBP issues can be a biased sensor, plugged tube or actual restriction in the exhaust system. If your system is too restricted the engine can't exhale and it will smother and die.

You need to determine which one is doing what.
Haha that's funny right there! Good way to describe it though.

To the OP, your numbers sound decent. I'm guessing the difference you're seeing on EBP desired and actual is because the desired is not reading the atmospheric pressure. KOEO EBP should be around 14.6-15psi. So if you're at 20psi actual EBP it's really only around 5 psi when you subtract atmospheric pressure, which would match with desired EBP.

I'd still make sure the EBP sensor tube is clear. It's a pretty quick thing to check. I've seen some really weird boosting issues caused by a goofy biased EBP reading.

Also make sure you don't have any exhaust or boost/intake leaks going on as well.
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Old 07-30-2014, 05:49 PM
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Thank you danny and justin.

Just a quick update - I have driven the truck about 45 miles with the scan gauge hooked up and the numbers seem to be really consistent - nothing really goes out of whack or goes too far off of what I believe normal to be. But I have noticed that my fuel mileage has dropped. My truck has never been one of those that claim to get 20+ mpg but it usually averages around 14ish. Looks like it has dropped to about 11-12 over the past week or so.

I am going to pull the EBP this weekend and make sure the tube is clear then double check for any intake/exhaust leaks.

Thanks for the help and I will keep yall posted.
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Old 09-17-2014, 05:30 PM
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OK, so it has been a while since this was active but an update...

I pulled the EBP. The tube had a little carbon build up but was not clogged. I blew it out and cleaned the EBP. I smoke tested the intake (from the cold inlet of the turbo) and the exhaust. There were only two small exhaust leaks - before and after the muffler at the band clamps so they are not the issue and I did not find any leaks on the intake side. The smoke machine only does about 1.5 PSI so I rigged up a rubber boot with an air fitting on it and put about 20PSI on both systems. Same leaks on the exhaust (nothing before the turbo) and no leaks on the intake boots or inter cooler. The only place I was getting any air from pressurizing the intake was out of the CCV tube - a little blow by and I pretty much expected that.

I have several thousand miles on it since the last post, an oil change, and new fuel filters with no change. I am at a loss... I am leaning towards either the actuator that controls oil flow to the VGT but I cannot see spending $250+ on an actuator on a guess. From what I have read there is Ford tool that you use to check the movement of the actuator to make sure it is moving as far as it should. The tool was like $650 so that is out of the question!

Guess Im gonna drive it till it dont boost no more and go from there!
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Old 09-18-2014, 05:16 AM
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Have you performed a VGT relearn? My truck had been doing the same as yours for the last 2.5 years, so I did the relearn last week and it appears to have solved all of my boost problems.

The following is from Diablosport Predator Update for 04 Truck - Ford Truck Enthusiasts Forums

The low power and lag problem could be a result of the sevice "Tech" not performing the VGT re-learn strategy after flashing the computer. Here is the strategy you can perform it.

KAM (keep-alive-memory) reset & VGT learn procedure

1. Drive the truck until the engine and transmission have reached normal operating temperature.
(The VGT learn procedure requires that the oil and coolant temperatures be at normal operating temperature)

2. Flash truck back to stock (Only need to do this if running a tuner or module)

3. Turn on the headlights

4. Disconnect both batteries

5. Short out + to - battery cables to each other (Make sure both batteries are disconnected before doing this).

6. Let truck sit like this for 10-minutes

7. Turn off the headlights.

8. Re-connect batteries

9. Cycle the key to the run position twice. Pause in the “ON” position each time until the wait to start lamp goes out (minimum 5-seconds) and pause in the “OFF” position each time for 10-seconds to be sure the PCM has "gone to sleep".

10. Start the truck and let it idle for a minimum of 5-minutes at normal operating temperature. This allows the PCM to learn the EGR valve closed position value. Also you will likely hear the turbo pitch change several times during this period as the PCM learns the necessary duty cycles for accurate VGT control.

11. Complete the road test Drive Cycle:
15 miles of mixed driving (*should* be enough in most cases) to allow the PCM to "re-learn" its adaptive strategy.

Note: Anytime the batteries are disconnected, the PCM will throw the P1000 code until the “Drive Cycle” is completed.


As for the Tow/Haul mode, the transmission must re-learn your driving style and loads hauled again as this was cleared when the truck was re-flashed.

Give this a shot if you haven't already. It worked like a charm for me.
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