CM871 poor power and fuel econ

[Grounded Pilot]

(04-11-2022 )JimT Wrote:  sounds like you have a real mess on your hands there. Owner should stop blaming cummins (as the manufacturer) for problems created by 3rd party shops screwing around and doing half arsed work.

Like rawze said, check out that programming. You could be chasing ghost problems or just be unaware of other faults/problems being hidden/suppressed by bad programming.

My thoughts as well, but the idea is already planted. But yes, this truck has been tore up from the floor up by some moron! It evidently had a Qualcomm at some point and they just cut and jammed that wiring behind the glove box. When I unplugged the connector to the wire bundle, my cab code disappeared. I’m not confident anything is correct on this truck atm!

   

“Spare” wiring I removed. About half still live and no cover on the exposed cut ends.
   

[tree98]

Oh boy

[Grounded Pilot]

More update. Not good though.

Got the wiring mess squared away. Aux TPS code gone and no more lights on the dash. Drove it and no change. Power Stops climbing at 48%engine load and about levels out about 385 indicated HP. Still sluggish. Still puffs white smoke on tapping the throttle, even if you roll in from the road, stop, hit the parking brakes, then tap the throttle it will puff white smoke. Still has a slight haze at idle all the time, engine temp doesn’t make a difference other than it’s not as bad right as you start it. But only take 30-60 seconds before it is hazing.

SO, went back to redo the injector leak down test, like Rawze said. Got bubbles again. C-A stroke on rear bank so I have a #5 injector issue. 4 & 6 have been replaced in the last 3 months so why not. (Side note, I wanted to change the whole set when we started having these problems but we didn’t). Now we will have 1,4,5,6 new in the last 3 months with 3 different shop visits and 2&3 are still original factory equip.

Also, I had went ahead and got the fueling actuator to replace the front bank actuator. Took the front bank fueling actuator apart and the plunger has a slight catch about the time it contacts the solenoid. Only on one side, and if you spin the plunger around 180° then it doesn’t catch. So I guess that thing is bad??

[Grounded Pilot]

Got it back together again. Reman injector and front fueling actuator. No haze, no puff of white smoke and runs a ton better!! I went ahead and re adjusted all the injectors since I had already done 2 and installed the third. And they were supposed to be adjusted less than 2 months ago. But when I adjusted the other 3 injectors, they barely had 5in/lb preload on them?!? Am I missing something, or did the shop just miss the adjustment by 90%????

Also, the thing still only goes to 97% throttle and only pulls 48-50% load but the indicated hp is up to about 430hp. The motor is smoother in all rpm ranges, responds better, and in general acts more healthy than it has in 3 months.

[Rawze]

(04-16-2022 )Grounded Pilot Wrote:  ... I adjusted the other 3 injectors, they barely had 5in/lb preload on them?!? Am I missing something, or did the shop just miss the adjustment by 90%????...

they don't get that loose on their own. Someone did not adjust them properly.

Matter of fact, I have seen many mechanics over the years make the mistake of setting the rocker torque on the ISX injectors to roughly 0-ft.lbs.. because they still think that the injectors for the ISX are the same as old 1980's big-cam engines.. and are just simply that under-educated about how more modern engines should be set. Engine runs like crap, it messes up the timing and metering actuators, and causes all kinds of power losses.

Still yet, i have seen plenty a mechanics that get lazy and do not turn the engine to the proper positions for each cylinder individually. They try to do 2 or 3 at a time.. and they all end up adjusted wacky too.

[Grounded Pilot]

(04-16-2022 )Rawze Wrote:  

(04-16-2022 )Grounded Pilot Wrote:  ... I adjusted the other 3 injectors, they barely had 5in/lb preload on them?!? Am I missing something, or did the shop just miss the adjustment by 90%????...

they don't get that loose on their own. Someone did not adjust them properly.

Matter of fact, I have seen many mechanics over the years make the mistake of setting the rocker torque on the ISX injectors to roughly 0-ft.lbs.. because they still think that the injectors for the ISX are the same as old 1980's big-cam engines.. and are just simply that under-educated about how more modern engines should be set. Engine runs like crap, it messes up the timing and metering actuators, and causes all kinds of power losses.

That was my thought. They were all pretty much 5in/lb so consistent at least, even the bad one I replaced. But the motor runs night and day different. And that could be the reason the front actuator went bad so quick then. Bad injector plus improper adjustment.

Next question. I may have located an inline 6 unit close by to buy. Does that system only run on Windows 7? Or will it run on my Windows 10 computer?

[JimT]

(04-16-2022 )Grounded Pilot Wrote:  Next question. I may have located an inline 6 unit close by to buy. Does that system only run on Windows 7? Or will it run on my Windows 10 computer?

Should run fine on windows 10. I remember seeing a video walkthrough for setting it up but not sure where to find it off hand. I actually need to set insite up on my newer windows 10 laptop as my old win7 based laptop is on it's death bed (bad hdd and screen/graphics card dying)

[Nilao]

Windows 10 will need .net framework 3.5 and 4.2? installed on it to run insite. They stopped including those .net versions in windows 7.

[Grounded Pilot]

Good afternoon ladies and gents!! I have finally gotten more things straighten out on this truck. All 6 injectors are now replaced and my fuel mileage has come up to running in the high 5’s most of the time. It is still sluggish on throttle and the turbo seems to lag behind. When I run the engine status monitor it says “defueling due to insufficient oxygen(boost pressure)”. I know it says it will do that under hard acceleration but it will do it about any time you increase the throttle % unless you are deliberately very slow on the movement. It has new filters and a new turbo and actuator. Also a new airflow sensor and exhaust gas pressure sensor. The OEM ambient temp sensor reads 72° all the time but the intake temp seems to read correctly. Also, my fuel flow jumps around a lot. At idle it will jump from .8gph to 2gph and it will jump 5+gph while pulling. Any ideas or is that another bad sensor?

I finally got ahold of a Cummins inline6 adapter kit. I’m still learning how to run the insite program and I need guidance on how to pull the programming to send it to Rawze for review? And where to send it Mr Rawze?

Thanks all!! I really appreciate your help and knowledge!