5.3L 2005 1500, Turbocharged, having slow loss of power issue.

[Zack Riley]

Stock 05 1500, 5.3l 4l60e transmission, 4x4.
We added a T70 Ebay turbo to it.
not much else.
I own a 4 bay mechanic shop and me, and my mechanics are starting to get a bit stumped.
Edge CTS3 Tuner chip (was on extreme for awhile, flashed to stock when issue arrouse)

 

The truck had loads of power, then one day, it started slowly losing power. At first it would seem fine, until it had been driven for awhile (30 miles), then it would act up. Now about 2 months into it, it is feeling sluggish all the time.

I would notice that on hills it would feel like im spinning the engine like mad, foot to the floor, 4 or 5 lbs of boost, but no acceleration. it also has terrible engine "pickup" at this point which feels like how a bad maf does. The truck now daily drives like this.

 

A few weeks after i first noticed the issue, i was getting on the freeway, truck is going extremely slowly despite the engine being at 2.5k and 2-3 lbs of boost. The CEL Comes on and starts flashing, my scanner showed MAF out of performance, o2's out of spec, cat below efficiency (have no kittys), and a Misfire in Cyl #4 and later that day a random misfire. I was trying to get up to speed and pushing it, when i heard a ticka ticka ticka noise from the engine and backed off, it went away and hasn't come back.

We changed the MAF sensor, the Crankshaft Sensor, And now the fuel Pump assembly. Live data showed us the 2 sensors were a bit out of spec but nothing crazy, changing them did help a bit. The fuel pump was having trouble holding pressure and had low volume so it seemed time to change it anyway. We replaced the spark plugs with a higher heat range as one's insulator exploded and another 2 had cracked.

 

Transmission seems to shifts fine, sounds fine, and shows clean, unburnt fluid. The engine sounds fine except for the lack of power, but in neutral it revs fine, sounds fine and has no apparrent issues.

 

No codes are showing but the issue continues to get worse and worse, affecting its daily drivability even for short trips now.

We bought a Hughes Performance towing torque converter with a anti balloon plate as we feel like maybe the power isnt getting to the transmission and it could use a beefier one for the long run. Also going to 42 lb injectors for more fuel and possible bad injectors? Not sure if this is the right direction or if anyone else has any ideas or input. Going to run a compression check tomorrow but like i said no misfires and the engine seems to be running like normal.

 

Any and all help is appreciated, where at a loss over here.