Hey. It has a cat and the exhaust system is cobbed in. I am waiting for a new 4inch cat back system from walker exhaust. I am going to check the wastegate operation as it sounds suspect. thanks.

 

I went into the cummins shop here in town and they gave me a list of what it could be. They also said it sounded like a real hair puller trying to figure out what the problem is. I bought a boost gauge and i will install it as soon as my wife gets home. I am hoping that this will narrow down my search. One of the many things the guy in the service department at cummins said to check was the linkage running to the fuel pump. The cummins dealer wanted $220 just to look at the truck before starting any work on it. and they would only put in parts that that engine came with stock and if i am replacing parts i want to increase horse power.

I'll let you know how it goes.

 

I went to my local mechanic and he lent me his vac gauge to check the wastegate actuator, but it wouldnt hold any vac. He will buy a new one tomorrow and let me borrow the new one. I also have been looking to install gauges. I like having the boost but can't decide on another. How important is the EGT??I also made a mistake with my earlier blog as my new s4 inch back exhaust is from the turbo not the cat which will be elimnated. I looked at the muffler and it is 4 inches straight throught the middle. It should howl and help with HP. Thanks for all the help. I have learned lots by just reading from U guys.

 

how much what the waste gate actuator and where are you buying it?

 

In the grand scheme of things, EGT is probably THE most important thing to measure when you start enhancing performance.

Boost is fun, and boost is informative, and the dynamics between boost, temps, HP, etc make for interesting discussions, but incorrect boost won't create a see-through piston. Excessive EGT, however, will turn a mobile 6BT into an immobile 5BT at an inopportune moment.

 

I get it, but i don't got it. I understand the dynamics as you explained it. However I have currently no way to monitor the EGT. I like the pod gauge set ups but where is the sensor installed. I have a new 4 inch turbo back exhaust ordered and will be installing that soon and would like to have the qauges to monitor both EGT and Boost very soon also. Thanks Geddys Uncle for the info.

 

The thermocouple for your pyrometer has two common install locations. Most prompt and scary will be at the fork of the exhaust manifold. If you choose there, don't drill and tap right in the middle, as there's a web there, dividing your manifold into 2 three-in-one manifolds. I could be wrong, but it's better to measure the temps from the rear cylinders. #6 is the hottest cylinder, usually, so if you keep that one safe, the other five will be OK by default.


The other common mount point is in the elbow immediately behind the turbine housing. Temps will be a little slower to read, and, as boost pressure rises, will be as much as 300* cooler than manifold temps. At low boost, it'll be near identical. (the temp drop is because some of the thermal energy in the exhaust flow is being captured and converted to kinetic energy running the compressor)

Either point is useful, but the panic zone is at a lower number "post-turbo" than it is pre-turbo.

Wherever you choose, implant the appropriate "cruising happy", "pulling good", "a little worrisome", "just for short burst", and "Downshift!" numbers in your head.



Or, you could get one that's got colors! Green, yellow, and red. Stay outta the red. Mine happens to be a colored and numbered Isspro, with a post-turbo probe.

Son's is pre turbo, black n white. Gotta actually read that one.

 

So I installed the boost gauge, and the highest i have been able to get it is "9" I have not taken it out on the freeway or climbed any hills yet but I'll do that tomorrow. all the rubber boots look connected on the intercooler and all boost lines running off the AFC look connected. any one know how to block off the waste gate to check for higher boost pressures and power? I don't ant to block it off forever just long enough to check if the wastegate has gone bad. EGT gauge is next, probably in a few paydays. after i get this problem fixed.

 

The turbocharger wastegate regulates intake manifold air pressure and prevents aver-boosting at high speeds. When the wastegate valve is closed, all exhaust gas flows through the turbine wheel. As the intake mainfold pressure increases, the wastegate actuator opens the exhaust bypass valve,diverting some exhaust gas around the turbine wheel, limiting turbine shaft speed and therefore, air output from the compressor.
To test the wastegate actuator, disconnect the pressure hose from the actuator, connect a hand-held pressure pump in its place and apply aproximately 19.3 psi pressure to the acuator. The control rod should move slightly and hold its position. If the rod doesnt move, replace the wastegate acuator.
Conversely it stands to reason that if the wastegate acutator is shot you would have little to no boost or HP.
I have yet to test mine and am eager to do so but the bills just keep coming and I've got to take care of business.

 

wow, thanks for the info, where do i get a hand-held pressure pump? will a bike pump with a pressure gauge work?