No boost......no power

[Roysbigtoys]

I have a 2009 Peterbilt 386 w/485 ISX motor w/566K miles, that has been de-mandate the Rawze way about 3 years ago. That's only about 50,000 miles for me, an excavating contractor. The truck has run great and my oil is getting cleaner every oil change. The other day it lost some power and boost. I found that the short tube between the venturi tube and the EGR tube developed leak, so it lost power and boost. Replaced the tube, ( I also made and installed a spacer plate on the back side of the EGR cooler ) but still no power or boost. I was having some trouble with the wrong date on my insite, so I limped it up to a shop where the supervisor hooked it up and said the IMAP sensor got cooked. Installed a new sensor and truck had boost and power again, bob-tailed it home and it ran as it should. A couple of days later I tried to move some equipment and it had no boost or power again. I thought maybe the sensor went bad and replaced it....still nothing. So I replaced the pigtail going into the IMAP sensor thinking maybe it got cooked also. Still nothing. In the meantime Big Roy from the forum ( who also helped me with de-mandate and other issues.... ) was able to help me with my insite. Today I hooked it and I have no active codes, but still no power.
What am I missing?

[Lonestar10]

i would take insite and data log the engine watching parameters and see if anything looks out of wack. could possibly be a faulty exhaust back pressure sensor thats stuck and the engine thinks its about to blow the turbo through the hood. or some other stupid thing.

[Rawze]

could be a lot of things. Pressure test the CAC, and entire engine for leaks. Check the turbo is still in good shape, etc.

Also, if it was 3+ years ago, you are in need of a software update. One of those updates fixes a power loss issue associated with the engine flagging the timing or metering actuators and it not recovering from it properly (a cummins problem, not a @m*m^2 problem), but the mm update (December 2017 versions and later) fixes this issue. - For all you know, you might be fighting this very problem and not know it, chasing ghosts.

have the file pulled from the ecm, e-mail it to me and I will update it for you.

Just a reminder ...
-- Anyone with Any kind of custom programming, or engine tuning that has been done,.. a person should always ask every couple years if there is any important updates that should be applied to their programming.

[Roysbigtoys]

Time for an update.
Since my insite was not working right I finally took time to pull the ECM and have Big Roy pull the cal for me and I am forwarding it to Rawze. I am hopeful the master will have some answers for me.;)

[Rawze]

According to the file you sent me, you have some wiring issues, or the ecm is going bad.

multiple errors for accelerator pedal, fuel shutoff solenoid, fuel pressure, IMAP, and exhaust gas pressure sensors are all showing they are shorted out.

These are error codes 132, 1241, 255, 547, 123, 2374.

=-- Also, your vin#, engine ser#, truck make and model are all missing in the program, and fuel milages down in the 5 mpg range, i think sucks too.

[Rawze]

I updated the file and sent it back to you... it was in desperate need of an update, and yes, it had that bug from the engine maker still in it, that makes it mysteriously loose power (and usually a bit of boost) in it too.

BUT: - You need to fix the problems you have with the truck too that were mentioned above.

You will also need to clear the codes out of the ecm once the file is put back in.

[Roysbigtoys]

Thank you so much Rawze for looking at my file and updating it. I did not know there were updates until reading on the forum just here recently. Rawze you are right my fuel economy sucks. But in my trucks defense, it and my lowboy weigh a little over 40k empty, 100k plus when loaded and I do a lot city driving. Very little "cruzing" down the road. I know I wasn't making 5 mpg before we demandated it.
Truck is back up and running....but I am still having trouble building boost and power. I changed the exhaust gas pressure sensor. It struggles to get 20 lbs of boost. I have checked for leaks with soapy water on all of my piping and on as much of the CAC as possible, nothing leaking. I probably still need to pressurize the CAC. Turbo looks and feels good, no oil leaks and normal turbo movement when you grab it with your fingers.
My insite also is back up and running. No active codes. The error codes that Rawze spoke of above are not showing now. When I am looking at the parameters, I really don't know what red flags I am looking for. I really need some guidance on whats normal and whats not.
Thanks

[tree98]

If you haven't pressurized the cac yet then you haven't checked for boost leaks, start with that. Sounds like maybe you were spraying soapy water on the piping and cac with the truck at an idle or not running?? That isn't going to tell you anything. It must all be pressurized, 20 psi is enough.

[Mr Hagg]

Check egr piping going around the back side of engine. I see these get holes and will leak exhaust gas and not let turbo spool up....You should hear a wooshhhhh kind of sound... If you have a block plate before cooler this dosent apply....