Paccar no pulling power

SCR high efficiency or standard mode? It will show in DAVIE monitor set. What kind of monitor set are you watching?

 

Unfortunately, the last monitoring I did I didn't include the engine mode. I was mainly checking the sensor before turbine and sensor after BPV. The mechanic who watched it said he didn't see anything out of normal. Since that recording I changed the sensor before turbine and it did not fix the problem.

 

Is this an EPA 10 or 13 engine?

 

It's EPA 10. All the aftertreatment is in working order btw. The def doser, eas ECM and rear nox sensor were just replaced as well as the first nox sensor not quite a year ago.

 

EPA 10 to me never impressed me as far as being a very responsive engine. Always seem to suffer from turbo lag and seemed like you need to keep them wound tight.
As with any modern EGR engine, air management sensor readings is critical for proper operation. The sensor, tubes, and piping check and cleaning isn't hard, but gets overlooked because it takes time. Venturi tube should absolutely be cleaned because a little soot build can throw off EGR delta P readings. Also, when and how was DPF cleaned last? Regen history, how often? Overhead last done? Why were injectors replaced, did a crankshaft overview indicate improper fueling one. It gets pricier, but I got in the habit of changing the EUP and injector as a set. I attached some information on air management inspection.

 

I've always heard they don't have much power either. But I've driven this truck enough to know that it should have more. When it has proper boost, it runs great. You don't feel like your toes are touching the radiator. I bought the truck with 730k miles in June 2020. It just turned 770k and on the dpf filter it says it was cleaned 11/19 and by the service records I received with it, would be about 40k miles before I bought it. The injectors were replaced after I had it dyno'd and that's what the shop recommended. They said to not worry about the pumps because if there were something wrong with one it would throw a code and/or would have a definite miss. Like I said earlier the truck runs very smooth. The overhead was done in the last 2k miles. I'm kind of with you on the venturi. I have replaced the Delta P sensor. But when I messed with the old one and cleaned the tubes, it always seemed to run good for a couple of hours and then go away. There's something resetting with the key switch that gives me the boost and then goes away. Its usually for a couple of minutes but I have had it go for 2.5 hours one morning. That was after I had the mechanic remove the turbo actuator and check the turbo and then reinstall and made sure it calibrated properly. In the service records, the turbo and actuator were replaced around october 2019 but the mechanic made a note that it took him three times to get it to calibrate. So thats why I had him check it. Anyway I'll look over the information you supplied to me. Thank you for that. I do have a mechanic that's going to swap the ecm with another 2013 paccar so we can eliminate or pinpoint the ecm being the problem. But that won't be for another week or two.

 

In my experiences, a weak unit pump doesn't typically code. Only time typically code for a torque contribution code is if completely dead/or broken spring. The control of most modern diesel is more based on modeling vs direct feedback from sensors so they tend to run worse the longer they continue to get drifted data and a key cycle tends to reset the adaptive learning.

 

So you think the pumps could be affected by a key cycle? If so could you elaborate? I'm trying to learn as much as i can about this engine. I'm on a quest to get this thing fixed once and for all.

 

Not the unit pumps, readings from air management sensors. Soot builds up in the venturi tube and as it does it throws off the readings for the EGR mass air flow so EGR manager thinks it is flowing less EGR gasses vs actual. To make it worse the temp sensor probes for EGR temp and intake get soot packed and boost sensor opening gets restricted and this throws off readings more causing more EGR flow because PCI is calculating incorrect exhaust gas mass flow. The lambda and Nox sensor will monitor the engine outlet oxygen/Nox concentration and if it is not too low it won't complain about the excess EGR flow. So the actual calculated mass of air entering the engine is off and fueling and driveability suffer. A key cycle will "reset" some of the learned operating conditions and as everything becomes heat soaked again after driving a bit driveability will suffer.
Unit pumps are very hard to diagnose as being weak unless they are just about completely dead. That is why if I isolate a malfunctioning cylinder, I replace them as a pair vs swapping around multiple ways.

 

What's your opinion on the EGR flush? Worth it or better to pull each sensor and the venturi etc. out seperately?