low boost and crappy fuel mileage. also egt ?

[HICKatvRACER17]

truck info is in my sig!

ive been reading up on the low boost issue. so i have a few things in mind to try.
my truck hasn't always had low boost, but i cannot remember when i first noticed it. it was for sure after all the performane mods ive done. it doesn't boost over 15psi at WOT, even on a tune. cold idle is like -.4psi. warm idle is like .44psi.

ive looked over all the ic boots and tubes. everything looks good. one boot has a small crack, but its not through. its worth replacing though. im going to screw with my vgt solenoid tomorrow and make sure thats working. my next step i guess would be pulling the turbo and cleaning it. truck has 106,XXX miles on it. I bought it as 87,XXX miles and have never cleaned the turbo (should have when i did the egr delete! UGH!)

few questions i have:
1.would these terrible boost numbers produce terrible fuel mileage? like 9mpg.
2.what boost numbers should i see at idle?
3.how bad can the unison ring be before replacing it? what does bad look like?
4.what are normal idle, driving, and WOT EGT's?

thanx for any help!!!

[HICKatvRACER17]

Edit. Warm idle boost is .08-.2 at rpms around 700

[Robs97z28]

That would be the first thing i would do. Pull the turbo and clean it.

[mhatlen]

When you tune the engine one of the parameters changed is the boost, what you are seeing on the boost gauge is lower then it actually is. Most tunes trick the pcm into thinking it is lower then it is so what you are seeing is probably 5 lbs or more than on gauge.

What I would do first is pull your ebp sensor and clean the tubing it is in, remove it from exhaust manifold and run a wire through it then blow out with air. Then see how you do, that tubing often plugs up with soot and raises hell with the turbo.
No you should be no where near 9mpg, I have 38x15.50 tires and get 16.5mpg on the highway and 13.5-14.0 in town but I am stock with a ficm tune only.
EGT max temps I am thinking 1,200 is the most you want to see but someone else with temp gauge will hopefully chime in and confirm that.

[eli.krahulec]

I am new to 6.0L's and need some clarification on a couple of terms... what is the EBP Sensor? How do I test FICM votage? What is estimated time to remove/reinstall and clean turbo (I am a HD mechanic, I know my way around tools, just trying to determine if this is an after work evening project or a weekend) Are there any other issues that I should attend to to increase mileage?

I also see 9 mpg or less. As far as I know, stock tune. EGR cooler still in, egr valve disconnected. CAI, Magnaflow exhaust, no cats. Mildly lifted, with 35-12.5/18's. At $4.50+ a gallon, its getting a little tough to swallow. Need a solution or a new truck.

[BobD981]

If your planning on cleaning the turbo, I would recommend just replacing the unison ring and bearings/bushings. Ford sells a turbo repair kit and its not that expensive compared to buying a new/reconditioned turbo! ($250 total if my memory serves me correct) Unison ring #3C3Z-6C885-A (like $175) andthe recond. kit #4C4Z-9V424-AA. I rebuilt mine and since the rebuild/cleaning I've put 30,000mi on the turbo and still making 25psi boost on a stock truck just my 2 pennies!

[85burban]

I pulled mine and cleaned it and reinstalled in about 3 hours. don't go crazy taking stuff off it's pretty simple. intake setup, degas bottle, up tube clamp, down tube clamp, intercooler tube, and oil feed tube should be able to sneek it out! mine however was rusted solid and is still sticking! so if anyone knows where the cheapest factory turbo is let me know!! good luck!

[HICKatvRACER17]

well i took a quick look at my truck today. right after i started it up i pulled the vgt plug. whenever i would unplug/plug it it would change the exhaust tone as it should. i did notice,however, that it doesn't do it automatically like it used to (while idleling cold it would cycle by itself)

i did also find and fix a problem:
when i was messing around with that plug i noticed a lot of air blowing on my hand. here it was the smaller black hose on the passenger side of the intake (map hose?) it was broke open and pouring air out. i cut it and reclamped it. now im seeing much higher boost (23ish tops) and driving boost is much higher and stuff.

i still plan to rip the turbo out and clean it. i sapose ill throw a rebuild kit at it while im in it. any options for cheaper rebuild kits online? i browsed real quickly and found a unison ring on riffraff for $128. any other places i should look for good prices?

thanx!

[HICKatvRACER17]

just ran a half tank of fuel today. all highway. i only got about 115 miles on a half tank. mind you i have 37's and i was going off the odometer on the truck, but still. i used to get WAY more miles out of a tank.

i was on the pre-loaded performance tune, 97% highway.

[kinnisoj]

Originally Posted by eli.krahulec

I am new to 6.0L's and need some clarification on a couple of terms... what is the EBP Sensor? How do I test FICM votage? What is estimated time to remove/reinstall and clean turbo (I am a HD mechanic, I know my way around tools, just trying to determine if this is an after work evening project or a weekend) Are there any other issues that I should attend to to increase mileage?

I also see 9 mpg or less. As far as I know, stock tune. EGR cooler still in, egr valve disconnected. CAI, Magnaflow exhaust, no cats. Mildly lifted, with 35-12.5/18's. At $4.50+ a gallon, its getting a little tough to swallow. Need a solution or a new truck.

Best way to test your ficm is to get a monitor (EDGE or the scanguage II is most popular) As far as how long it would/could take to r/r a turbo I would say a couple hours.. There is guys he who will say "I can do it in 30 minutes...." but I find getting the darn thing sealed with no leaks to be alot of fun...but over all not a hard job