loss of power help!!!

[Tmitchell]

ok here are the symptons:
1.truck has no power when pulling, when not pulling anything the truck runs a little better.
2.when i accelerate the truck will shift fine and accell ok as long as i dont push down on the pedal too much, if I do push the pedal down too far the truck boggs down.
3.shifting from third to fourth the truck bogs and makes a swooshing noise from around the turbo and all power lost.
4.some days the truck runs better and some days it runs worst
5.ABS light is on


things ive tried:
1.ive unplugged about every sensor to run in default with no improvment
2.checked all connections with air intake and even replaced all the boots


things i've replaced
1.complete new rear end auburn limited slip, new ABS sensor
2.4" turbo back exhaust
3.new sensors include: map, ICP, ABS, CPS,
4.new intake from filter to turbo

any help would be greatly appreciated

[justinmix]

If it's not throwing a check engine light or logging any codes then I would suspect fuel pressure issues. Low fuel pressure will not cause any codes but will cause the symptoms you're having. Since your truck uses a mechanical fuel pump it's common for them to get weak and not provide enough fuel pressure, especially under load. There is a schrader valve on the side of the fuel filter housing. Hook up a fuel pressure gauge and run the truck while monitoring fuel pressure. It should never drop beneath 40-45 psi under load. If it is start with replacing fuel filters then retest. If still low I'd check the fuel pressure regulator and fuel pump. See what fuel pressure is running at idle and wide open throttle in park. Fuel pressure should be around 45-60 psi then.

If all this checks out then could be a EBPV issue.

[T-ROD]

I agree start with the fuel pressure testing then go to the EBPV. The wooshing sound does make me think EBPV and its an easy test to find out, just unplug it and see if that helps. Last winter mine started making a strange wooshing sound that I could hear really good if I was standing near the end of the exhaust. I unplugged my EBPV and havent heard it sense.

[Tmitchell]

Originally Posted by T-ROD

I agree start with the fuel pressure testing then go to the EBPV. The wooshing sound does make me think EBPV and its an easy test to find out, just unplug it and see if that helps. Last winter mine started making a strange wooshing sound that I could hear really good if I was standing near the end of the exhaust. I unplugged my EBPV and havent heard it sense.

First of all thanks for your help

I've unplugged both the sensor and the plug at the pedestal
With no difference noticed
I also hooked up a pressure gauge to FPR, the pressure was constantly going from 40-60psi back and forth is that normal?
Or should it hold a constant pressure, and this was at idle.
I've also replaced all the blue fuel lines and both black return fuel lines, cleaned out the FPR and the fuel bowl.

[justinmix]

40-60 is normal, but you need to watch fuel pressure when driving, especially under load when it's acting up. You can have good pressure at idle but it can drop off under load.

[Tmitchell]

Where do I get a gauge that will have a hose long enough to reach in my cab?
I bought a 50$ one but hose is too short to reach in cab?
And I hear everyone talking about boost psi
Where do you get a gauge for that and where does it hook up?
Thanks for your help

[351fifty]

Could try a gauge with an electric sweep so you don't have to run fuel in the cab like that, and just make it a permanent addition in the cab for future reference.

[justinmix]

Boost psi can be read with a scan tool. It's listed as MAP (manifold absolute pressure). Or you can T in a gauge to the MAP sensor hose. The MAP sensor is located on the passenger side, mounted on the heater/ac box. It has a small rubber hose that runs from the passenger side head intake runner to the sensor. This is the hose that you would T into.

[351fifty]

Thought we were checking fuel pressure tho?

[justinmix]

Originally Posted by Tmitchell

Where do I get a gauge that will have a hose long enough to reach in my cab?
I bought a 50$ one but hose is too short to reach in cab?
And I hear everyone talking about boost psi
Where do you get a gauge for that and where does it hook up?
Thanks for your help

Sorry, should have clarified that. I was just responding to his question about boost readings.