Inlet port shut off motor delete (CDI2)

[Alex Crow]

3x wires, one will be brown or mainly brown, connect the resistor between the other 2x.

 

[stumo]

Also an 02 ml270 here. My flaps are still working but I want to stop them actuating. If I just unplug the motor and do the resistor trick, will the flaps be/stay open mechanically by default?

I have noticed that mine are leaking intake oil through the spindles a lot more now after running no EGR for about a year. I guess the lack of soot is allowing the spindle seals to leak more. I figure if the spindles are prevented from moving it will help reduce the leaking.

 

[Alex Crow]

The return spring on the M55 will hold the flaps open, assuming everything is mechanically connected OK and the motor is not jammed.

 

[jibcl500]

I cannot remember if the 642 has a 3x or 5x wire M55, if a 3x wire then possibly.

There may be other issues arising though, such as airmass faults being logged due to the slightly higher than expected air flow. Sometimes airmass deviations are logged as EGR faults, as this is the main system of monitoring the EGR system.

Alex

Yes 3 wire.

jib

 

[brenner]

320 CDI

A popular mod now, is to disable the inlet port shut off flaps, particularly on 270 CDI (612) engines.
This is usually done because of damage to the flaps from wear and tear, accelerated by EGR gasses.

It is possible to replace the entire manifold, but at significant cost, and some of these cars are old and unloved now!
Even if the manifold is changed, problems can still occur with the actuator motors (M55) jamming and signaling faults to the ECU.
So, how to do without the system...

To remove the flaps is simple, but leaves big holes in the intake manifold.
To plug these holes, I cut short sections of 16mm threaded bar, tap threads in the holes, fit the plugs with superglue, and finally drill and lockwire them for good luck.

With me so far?

But we still have a problem, if the motor is removed, a fault code will be logged, stating 'M55 inlet port shutoff motor signal wire resistance too high'.
Yes, the motor can be left in place and connected to the loom, and if working there will be no fault code.
However, as is often the case, the motor may have heavily worn gears, and frequently jam.
This will log a different code - 'M55 inlet port shutoff motor signals fault through ground keying', which simply means the integrated circuitry in the motor has seen that its mechanism is jamming, and has signalled a fault to the ECU by temporarily grounding out the signal wire.

So, if the motor is worn and jamming, we have a problem, but we do not want to replace it with a new one, especially now there are no flaps fitted.

Getting there now...

So, to cut to the chase, all we need to do to avoid logging fault codes, is wire in a resistor between the signal (PWM) wire and the 12v wire to the M55 motor.I have found that values from 1k to 10k ohms work - 20k ohms is too high.
I have opted for 4.7k ohms on my testbed, and so far all is well - no codes being logged.

I should add that you can buy these mods on ebay http://www.ebay.co.uk/itm/Inlet-por...arts_Vehicles_CarParts_SM&hash=item1e6a7d237e , but they are rather more expensive than a 4.7k ohm resistor...

Really great fix. I would assume that this will work on a 2002 320Cdi, as it just has one more cylinder??? Thanks for your answer

 

[Alex Crow]

Really great fix. I would assume that this will work on a 2002 320Cdi, as it just has one more cylinder??? Thanks for your answer

That could be a W211 or a W210, but it ought to work on either, yes.

 

[brenner]

Thanks.
My inline 6 320 cdi was smoking on acceleration. I found that the rod from motor to the linkage that operate the flaps was missing. I replaced it, but it made no difference regarding smoking. I then jammed the flaps open, and took it for a test drive. It did not smoke anymore. But it accelerated slowly, and would not kick down when I floored it. Obviously it was in a "safe mode"
It did not smoke when in Neutral with pedal to the floor. I removed the piece of wood holding flaps open, and acceleration returned to normal, but with smoke. I wonder if the motor that opens and closes the flaps could be shot, and the flaps are closed, causing a "too rich mixture" (as if a choke was on),
making it smoke.
I have the feeling that my flaps stay in the closed position. Any thoughts?
Thanks
Fred

 

[stumo]

I tried in vain today to disconnect the M55 motor connection at the manifold on my ML270 in-situ. I can just see it from under the vehicle, but there is no way in hell I can reach it top or bottom without another elbow joint and forearm length added to my arm.

So...

What about disabling it at the ECU end, kind of like the EGR shunt, but cut the 12v supply wire to the motor? Then the resistor across on the ECU side to the M55 signal? Then the motor connection can remain plugged in. I might give it a go and see what happens. Worst case - out comes the manifold, which technically is the complete solution, but its a lot of work.

EDIT: Its done. You need to snip the signal wire too. Its easy to do, both pins are on the same sub-block of ecu plug 4. Pin 22 and 33 just snip them off with a short tail and join them with the resistor, (on the ecu side of the snip), job done.

 

[bhonok]

inlet motor diabling

Hello fellows. Can somebody clarify it for me. In post 23 Alex says that motor spring keeps flaps open. I was under impression it is another way around. When rpm increase motor gradually pushes an actuator to open flaps from initially closed position . On my ML270 CDI I have disconnected linkage and moved flaps lever all the way towards a cabin and jammed them . Did I closed them instead of opening???? I have shunted the connectors red and white wires with 5k ohm resistor.Thanks

 

[mersum1es]

Hello fellows. Can somebody clarify it for me. In post 23 Alex says that motor spring keeps flaps open. I was under impression it is another way around. When rpm increase motor gradually pushes an actuator to open flaps from initially closed position . On my ML270 CDI I have disconnected linkage and moved flaps lever all the way towards a cabin and jammed them . Did I closed them instead of opening???? I have shunted the connectors red and white wires with 5k ohm resistor.Thanks

Yep, should be moved and jammed forward position...

 

[cutaresku]

In post 23 Alex says that motor spring keeps flaps open. I was under impression it is another way around.

+1. The spring keeps the rod and flaps closed, as I checked with my old manifold.
CLOSED: rod is in normal position, to the front of the car.
OPEN: rod is going fully back to the windshield.
Just try it with STAR on M55 test field.

 

[mersum1es]

+1. The spring keeps the rod and flaps closed, as I checked with my old manifold.
CLOSED: rod is in normal position, to the front of the car.
OPEN: rod is going fully back to the windshield.
Just try it with STAR on M55 test field.

Hmm, this is odd... EVERY instructions I've read has stated that linkage should be jammed forward But if done with star, that must be right - anyone know is there different structures of manifold flap actuators?

 

[cutaresku]

Forward=rod closed.
Back=rod open.
At least with my STAR and my cdi2

LE: 220cdi (611.961) - my case.

 

[Alex Crow]

Yes, some go one way, some the other.

For example, a 2000 E320 cdi will be opposite to an E220 cdi.

 

[stumo]

So which way is the ML270? I've just left mine free under natural motor spring pressure as per the advice on here.

I don't drive it much as its the wifes car so I didn't have a back to back comparison when I did the mod, but it seems to go allright and with zero smoke. Would be nice to know if there were some more horsies waiting to be unleashed lol. But mostly I'd be worried about a worn flap introducing itself to the valves because they must be under a bit of strain if held closed at high loads, which is what led me to accept that free was open, since its fail safe.

 

[Alex Crow]

Just had a read on WIS, and it does state that they (611, 612 and 613) have the flaps help open by spring pressure when the M55 is de-energised, as I suggested way back.

This is the only logical way of designing it, when you think about it.

EDIT: Pierburg make the system, have a look at their literature, and see the manifold with motor unplugged and flaps open... http://www.ms-motor-service.com/ximages/pg_si_0071_en_web.pdf

 

[bhonok]

Hi Alex. So the whole purpose of M55 on ML 270 CDI is to close flaps rather then open them.. Right? Then if I want to jam flaps open I should move flaps linkage all the way toward the cabin in direction opposite of motor arm (or rod) which then returns to a default position all the way towards a radiator. ????

 

[Alex Crow]

Hi Alex. So the whole purpose of M55 on ML 270 CDI is to close flaps rather then open them.. Right? Then if I want to jam flaps open I should move flaps linkage all the way toward the cabin in direction opposite of motor arm (or rod) which then returns to a default position all the way towards a radiator. ????

This is too much to ask from my memory!
All I can do is repeat, the spring on the M55 arm opens the flaps, with the M55 unpowered.

 

[turbopete]

i hope this isnt a problem i am likely to encounter!

is there a way to tell which CDI you have?

 

[bhonok]

I have ML270 CDI 2001 ( w163) with 612 engine