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Topic: M11 repair (Read 815 times) previous topic - next topic

M11 repair

Have not driven the repaired coach yet but I have been chasing what I thought was a power loss in the motor.

Most would kick me as it runs well.  But that's a relative term and not having driven a number of similar coaches new it's subjective.

My first thoughts were the known issues on the Internet.  Manifold air pressure and barometric pressure. 

Cummins mechanic was checking both sensors with the ignition on.  He heard the injector buzzing next to him. Engine not running.  Wrong.

Insight showed a 343 and a 121 code.  One is the crank position sensor.  Bad.  Injectors were not firing at the correct time.

Not sure which is which but the other code in non performance.

He replaced the two other sensors with updated ones for more reliability but the originals both tested ok.

No check engine light showed ever.  Not sure if its supposed to or is there a problem in that circuit.

The idea that the buzzing is audible with the ignition on at some points in the engines rotation while not running may allow a quick self test for an owner.

We will see if much difference shows but the crank postion sensor was bad on mine.  117k miles.

Resonator next......
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: M11 repair

Reply #1 –
My engine position sensor was bad andit threw a code. It also had a hard time staring until it was fixed. 
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon

Re: M11 repair

Reply #2 –
Turns out my m11 had a failed cam position sensor.

The cam mechanically compresses the injector on these then the Hall effect sensor electrically opens the injector.

The $36 sensor was a common failure item when these were new in trucks.  3-4 years all died.

End of original sensor was a metal tube with a potted pickup in the middle.

Oil gets past the seal and gets into the internal coil.  Shorts it out to the housing.

Erratic signal at the start as evidenced by a non smooth idle with random firings of the injectors.

Also can have a buzzing noise from the injectors with the ignition on and the motor not running.

Total failure leaves you pushing the coach.  No backup.

ISM has both the cam position sensor AND a crank position sensor as a backup. M11 does not.

Also installed an updated more accurate barometric pressure sensor from cummins.

Engine idles smoother. Less noise.  Revs slightly better. 

May pull the injectors some day just to see after 17 years and unknown care and feeding if they are putting out the correct volume and patterned squirt. 

Also replaced the manifold pressure sensor. Both pressure sensors read good but both had updated more reliable and more accurate parts from cummins.
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: M11 repair

Reply #3 –
What is the part # for the cam sensor that they installed on yours?  If you don't mind sharing. Would like to compare yours to ours as they are about the same age.

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: M11 repair

Reply #4 –
Quote from: Pamela & Mike –
What is the part # for the cam sensor that they installed on yours?  If you don't mind sharing. Would like to compare yours to ours as they are about the same age.

Pamela & Mike


4326596 is the cam
The others are
4902720
4921501

Not sure which is which
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: M11 repair

Reply #5 –
Thanks, now I have to go pull my books and see if that is the same as we have.

P &  M
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: M11 repair

Reply #6 –
Quote from: Pamela & Mike –
Thanks, now I have to go pull my books and see if that is the same as we have.

P &  M

Erratic noisy idle and a buzz with the ignition on not running are non check light symptoms

No check light
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: M11 repair

Reply #7 –
Bob,

The rain has let up enough that I was able to get out to the barn and round up some paperwork, The part numbers that I have for our Celect are the same as yours. For the benefit of others the #4902720 is your ambient air pressure and the 4921501 is your intake manifold pressure sensor. The  4326596  Cam sensor fits a lot of Cummins engines and is one item that you should carry with you as a spare. One word of caution to those who have the M-11 Celect plus that is the same vintage you still need to double check with your engine # prior to buying parts as a spare.

As a side note the cam sensor has a primary sensor and a back up all in that one piece. That is the reason it has 4 wires, 2 for primary & 2 for back up.  Between the sensor and your ECM it can swap back and forth if primary fails. With it swapping back & forth can cause a misfire, miss, and improper injection time as the computer don't know what position the engine is in. (the same symptoms you mentioned) At least you found it before you were left setting on the side of the road.

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."
 

Re: M11 repair

Reply #8 –
The replacement cam postion sensor has a solid aluminum cap instead of a potted end of a tube
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4