Rebuilt the engine around 5000 miles ago. put in II 60 hp injectors. as of late the power output seems to be gradually decreasing and my egts are increasing. I was wondering if it were possible for a turbo to loose efficiency. unloaded, medium-heavy acceleration causes the pyro to reach 1500 degrees in just a few seconds (pyro is in the manifold on the 4,5,6 side) cruising is a pretty normal 700 - 800 degrees. idle is around 275-350 deg. anyway the turbo (stock) spools normally and makes 30 psi but it just feels like im not getting what the turbo should be giving. i run the pmt on performance with low end power, so with the injectors im runing around 130 hp worth of extra fuel.

at around 3000 miles i did a few (less than 3) 0 - 60 runs with defueling off and egts almost reached 1700 degrees needless to say i dont do that anymore but the run was 7.1 sec on the fastest one. now at 5000 miles i run around 8.5 defueling at 1450

anyway im not sure what is amiss or what to check. im supposed to pull a camp trailer to the mountains this friday, but am a little leery. any ideas would be greatly appreciated.

Thanks in advance,
Travis

 

I believe I would look to the injectors first.

 

Forgive my ignorance, but what would I be looking for? Stuck injector, galled nozzle, leaking injector?
Thanks

 

I agree with Millerboyzdiesel, but on the off-chance, check carefully for a boost leak(s) first before digging into the injectors. Ya might get lucky.

 

That would be lucky. could you have a boost leak and still be able to build full 30 psi?
on that subject i do get heavy turbo flutter quite often. as with everything else, it seems to be getting worse. the exhaust is extremely loud, its hard to hear anything, what would be an effective way to check for boost and exhaust leaks?

 

As far as injectors, you can check return rates. Past that its sending them out to be checked. Exhaust leaks are pretty easy just look for soot. Boost leaks, a smoke machine is very handy. Beyond that you can check boots, and look for gaskets pushed out around the intake plenum plate.

 

Depending on how big they are, boost leaks are usually pretty obvious - slower to build boost, or inability to even achieve WG level at all.

If they are small, then that is probably not going to be what's causing your problem.

 

I think i may just have an efficiency problem. i made an apparatus to pressurize the intake and after tightening a few boots i hear hissing coming from the wastegate, i have the 04.5 so i have the electronic valve that opens and sends air through a hose to the diaphram to open the wastegate. the strange thing is, at 6 psi there is lots of air being diverted through the electronic valve. shouldnt this valve stay shut until 32 psi. i have never hit higher than 30 by the way. i have heard stock boost was 32. anyway i am guessing the valve is broken or stuck or just confused and it is causing the turbo to be less than efficient. any thoughts?

 

If you can verify the WG is actually jammed open it is likely the actuator stuck. The WG should not open until you hit 30-32 psi and then the controller has to demand it. With a boost fooler installed or the WG controller disconnected you should be able to pop 40 psi realy easy.

 

so i built the pressure to 12 psi with the air compressor then unplugged the hose that connects the electronic valve with the diaphram to open the wastegate. lots of air came out of the valve. i plugged the valve with my thumb, and could still hear air hissing within the valve. plugged the hose back in then put the air intake back together. went for a test drive and now can only build 27 psi max and it spools up much slower. computer gave me codes p0069 and p0236. seems like the valve is internally damaged, or mabey the map sensor is giving it false signals. when i was doing the boost leak test and was plugging the valve with my thumb, i did notice the whole valve assembly felt warm. the rest of the truck was cold. also mabey i pushed too much boost to it with the engine off. highest was 18 psi. not sure what to do now