o havew a 99 f250 and the highest boost i have ever made out of it is about 3-5psi. i put some vacuum on the canister that the red vacuum line plugs into and it wont hold it. also, when the truck is running or off, the rod is fully in, and the way i determined that thing works it should be all the way out when its off or trying to build boost, but im not sure,

any help guys?

 

Red line won't hold pressure as it is tied in to the intake tract. The rod should be completely "in" the can and it fluctuates outwart to control boost.

The wastegate references boost only to actuate.

 

i didnt apply vacuum tp the red line, i applied it to the canister that the redline hooks to and it wouldnt hold it. just to verify, when the rod is "in" then the wastegate is closed? and when pressure is in the red line it pushes on the diaphragm and opens the wastegate by extending the rod? if this is so then what other causes of low boost are there that i should look for? or is 3-5psi normal (i have a 100hp chip btw)

 

There is no vacuum like a gas engine on a diesel. That canister is controlled by boost pressure. The control solinoid, to the best of my knowledge, controls that canister by a controlled bleed off of boost pressure as it's fed to that system through an oriface. If you follow the control lines you will see where it is supplied pressure coming from a nipple on the Y-pipe.
Looking at the canister it is spring loaded to hold the wastegate valve closed. If you can pull outward with your hand on the control rod and move it with some effort, then it's too loose. The correct adjustment for the control rod is to supply 5 psi to the canister and adjust the length of the rod until it drops onto the lever. A lot of us here, including myself have adjusted that rod tighter to get a quicker spool up. I have it cranked all the way down and it takes 15 psi to drop the control rod onto the lever. With the wastegate control connected, even at that tight of a setting I'm lucky to hit 20 psi. If I disconnect it, easily reach 25+ going up a hill.
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You should have a lot more boost than 5 lb, especially with a 100HP chip and I would be looking at all the clamps, boots, etc to make sure they are properly seated and not bleeding off.
The other possibility that comes to mind is to make sure that the exhaust back pressure valve is fully open.
Other possibilities are poor fuel pressure, weak HPOP, clogged air filter.

 

the air filter is good. ill try adjusting that rod. i know not to turn it because ill rip the boot. what should i use to supply pressure to the canister to adjust it? also, what is an HPOP? ive heard of it but im not sure what it is

 

Yeah, on a gas car it can take 15 psi to open a wastegate. On the PSD the "bleed" can open the WG when it sees 5 psi, when in reality you are pushing 20.

And as KwiK said, and I before mentioned, the wastegate uses boost reference.

DO you have any codes?
That would help us, help you better.

 

the HPOP is the High Pressure Oil Pump. this nifty device pressurizes engine oil to over 3000 psi, and it is fed via a common rail in the cylinder head to the injectors. then the HEUI injectors use this oil pressure to do the work of super-pressurizing the fuel to about 20,000psi, when it sprays out into the combustion chamber. a weak pump could be low on pressure, which means the injectors do not pump as much fuel as they should, which can equal low power. my advice is to remove all of the intake boots on the pressure side (after the turbo) and check them for holes and or tears. then clean them and the two pipes very well. in total there are 6 boots you should do. two are orange, below the compressor manifold (where the turbo pushes the compressed air out) and are harder to get to than the other four, but still easy IMO. then if your power still feels low, take off the intake boot going in the center of the turbo, and look to see if anything on the compressor wheel looks abnormal. may be some chipped blades, not moving air like it should. i would also go to a parts store with an OBD II scanner and check for codes. Diagnostic Trouble Codes (DTC) help us out in finding the problem better. we are all just shooting in the dark without codes to help us. my shot is above.

 

Where are you taking your boost gauge signal from. If you are taking the reading from the red line at the wastegate actuator, you will never see more then 5 psi.

 

Strokin and Kwik are really good at this, But i just wanted to add something that just my 2 cents.

How does the truck Run, its not a gasser so it dont really build speed till the boost is up...could it just be the gauge...


If your wastegate canister wont hold vacum then it wont hold pressure,
But even with a bad canister I can see it not building boost as lond as it's connected to rod tight and not flappin around
if it is bad it my be time for a Banks BigHead, since i put mine in I can hit 27-28 psi boost really easy....

 

Banks BigHead is over rated. tightening the link on the end of the rod does the EXACT same thing for $180 cheaper. i have a working stock wastegate actuator canister laying by the phone out in the kitchen, that i would let go of if someone needed it.

 

Im just aswering from my situation and what happened with my truck,
I took my actuator and tested it to make sure the diaphram was ok and also tried the tightning of the rod like 5-6 more turns, and it did help at idle and low boost, but never hit anything over 21 at anytime,
After I installed my BigHead, (got it used, never installed for $50)
I had no problem getting to 25+ real quick,I have even seen 28 but I dont like to keep my foot into it that hard
Im not sure just my 2 cents,
I think that because of the heavier spring weight combined with the bigger canister delaying the volume pressure, that it may take a hair longer to activate then the smaller one, that is why im seeing those numbers, I could be wrong but its just what i Believe,
I am under the impression that the factory ones under normal settings will let the wastegate open a little under low boost conditions, So as for myself I really dont think you can compare the Bighead to the factorey one since you are still changing the over all lenght of the actuator on the wastegate by turning it in and not letting it fully do it job..I live in the cold climate area so I do like the warm up times..