couple thing I noticed when I changed turbos
the waiste gate actuator spring was real weak on old turbo
the hoses leaked although tight,new hoses fixed that
so I think I had 3 boost problems

 

glad you got it fixed did you build a leak detector to help you find the leaks??

 

no kinda accidently found hoses leaking,shop I had change turbo didn't change hoses,and boost was still a little low,after hoses were changed boost came to where it belonged

 

close but no cigar.

The waste gate is actually closed (allows turbo to build boost) when no pressure is applied from the red line.(which is most of the time) the red line will apply 8-10 psi of POSITIVE pressure to the WG actutor (there is a diaphragm over the spring inside the actuator) and the rest of the force to the WG is applied by the pressure of the exhuast gasses pressing on the wastegate valve itself. The spring inside the acuator takes a compressive force of 35-40 # to collapse it completley. Your wastegate never really opens all the way.

it is possible that your WG is leaking, it takes pressure from the actuator spring to prevent drive gasses from escaping around the WG door, thus causing the door to open at a lower drive pressure and not spin the turbo as fast.

The correct way to adjust your WG actuator is(with engine off) try to move the acuator rod laterally(side to side) and check for slack . If there is a small bit of slack, then remove E clip that holds actuator arm to WG and tighten the rod end a couple of turns. replace rod end over WG(this may require some force to pull against the spring inside the actuator) make sure you WG has a positive seal by checking for slack again if none is felt replace e-clip and drive.

the WG actuator is a very simple device, its rod that compresses a spring when it is pulled upon by the forces of the drive gasses pressing on the WG door, and pushed upon by a positve pressure of 8-10psi from the red line.

the tighter your door the higher your drive pressure (the pressure of the exhaust gasses that spin the turbo), Here is where caution comes in to play, if the waste gate does not open the drive pressure becomes too high and thrust bearings start to recieve to much pressure and tend to fail.

By unplugging the red line to the WG actuator you have increased your drive pressure because there is no helping force to compress the actuator spring.

Also make sure you tighten the clamps on all your CAC boots, and Spider boots.

 

Did some testing and inspections. first was to disconnect the red line from the WG. boost went up to 17psi (hoping for 21). So it looks like the WG is part of the problem but no all of it. There is no slack in the actuator rod. I also inspected the turbo inlet, all looks happy with no noticeable endplay or run out (won't wiggle). All four joints on the up pipes show no signs of leaks or soot. The engine is fairly clean and I don't see any exhaust leaks. clamps all tight.


since this problem has slowly happened, it's hard to tell what is normal behavior. I drove a friends PSD with similar mods and it hits 20psi at half throttle, fairly quickly from a stop. my truck build boost slow in comparison. if I roll into the throttle at say 30mph, the trans will downshift and I can get the pedal to the floor before it builds even 1 psi (WG hose off). This seems wrong.<O</O


is it possible that there is a sensor that causes the computer to limit fuel? I don't see any smoke even at WOT.<O</O

The truck has had a fairly easy life, never abused with only 60k miles. <O></O>


Should I build a PVC leak test thing? I assume it goes onto the pipe that exits the turbo (in place of the turbo impeller) that goes to the left side of the cooler.<O</O

Is there any information to be gained by putting the 'puter back to stock?<O></O>

 

Yes you need to invest the $10 and buld a leak detector. I am thinking that maybe one of your boots has a hole in it. It may not be evident till its under pressure

Checkand make sure your MAP line from the spider to the MAP sensor is not cracked or split.

 

Ok. Now i have no suggestions left. maybe i have 2 more they are just shots in the wild until somone who has more knowledge than me (99% of all the other members) have time to respond. My first guess is maybe the map sensor? Maybe it isn't working well enough to allow the PCM to dump in the fuel it should? https://www.ford-trucks.com/forums/5...map-mpg-2.html check out post #23 it will show what to look for to test it. And somwhere else in that post is the calculation to convert your local barametric pressure Into PSI like the map sensor reads and you can get a rough idea of your pressure from here www.weatherunderground.com Ok my other guess is if your truck is running ok, as in it doesnt feel sluggish. It could be your boost gauge or the gauge having kink or small leak?

 

does not take much to make a leak detector...3" PVC and a air reg..

 

Ok, I built a 4" shrader valve with a gauge ($2.34 & some leftovers). saw this in a search

"Simply connect this device to the inlet of the turbocharger and pressurize with a standard compressor to 10 psi to 20 psi. You will hear even the tiniest of leaks in seconds."<O></O>

So I pulled the hose off the air box and inserted my 3" PVC cap thingagiggy. the clamp is a little small so a wrapped with some tape (bad idea). Added air but system would register pressure on either gauge (boost and tester). leaks somewhere but can't hear it. Opening the shrader didn't let much air out.<O></O>

Hmm. The 'low pressure' rubber hose to the turbo inlet swells when air is added, so it must hold some pressure. I got in for a close look. POP! leak tester to the forehead. Dooh! <O></O>

Where's my beer, at least it doesn't leak......<O></O>

 

Also make sure you tighten the clamps on all your CAC boots, and Spider boots.

I found some filthy red hoses that feed air to the heads. tightened the clamps. seems to hold some pressure now with the tester connected. reconnected the WG hose and test drove
- 16 psi max (was 14)
removed WG hose again
- 18 psi max (was 17)<O</O
So I still have two problems
1) WG
2) leak someplace<O</O

being that the spider (? what the heck is a spider?) to head hoses were filthy, could there be greasy gunk between the hose and head fitting that will not allow a good seal, regardless of clamp pressure? Looks like removing them to clean them would be a major PITA. I tried soapy water on all fitting to find leaks, but in the dark it's hard to tell.<O</O
should I be able to pressurize the system with the leak tester and have it hold pressure for a few minutes? I could only get it to about 8psi on the boost gauge and it fall about 1psi every 2-3 seconds.<O</O

 

if you took them off would be a good tome to change them,sometimes you won't see a hole but they still leak

 

how much $$ are all the hoses? where to get them?

should I be able to pressurize the system with the leak tester and have it hold pressure for a few minutes?

 

This is where I got mine


http://www.dieselsite.com/index.asp?...RODGROUP&ID=14

 

I removed and cleaned the CAC tubes, boots and manifold to see if I could find any problems before spending a grip of cash on new boots. Looks like the o-ring between the compressor housing and the manifold was leaking. There is a light yellow hardened oil deposit on the back of the manifold that will not clean off with anything. I gave Ford $8 for the o-ring (no, they didn't use vasoline). Probally could have got one from a HW store, but if it leaked I would have to come to the realization that I am a cheap a$$. Hopefully this will fix my low boost issue.

 

Let us know how it goes. good luck.