96 M119 eng runs great but keep getting code 410 secondary air injection malfunction. I have replaced all o2 sensors,the air relay K17,ECT sensor.
The Air pump runs on startup for about a min.It also runs for a short period when the temp comes up over 80c (closed loop).
My snapon mt2500 will not turn it on when you go to actuator tests unless the eng is off (weird?)
I can run the pump all day with eng off with the mt2500 tool
so I can not check the o2 sensors drop below 40mv.
Shutoff valve works good tested it with vacum tester.
Electric changeover works tested it with 9v batt and vac tester .
Removed Air pump and shutoff valve blew air and smoke in and it comes out the exaust so ports are not cloged in heads.
Found the inlet screen for air pump totaly cloged with grease and dirt,so I cleaned it.I also poured some injector cleaner in the pipe and blew it out the exaust it came out in a fine mist from tail pipe.
Can I test the pump for air flow and what else can I do b4 putting this thing back together tomorrow???
Can the pump work but not put out enough air???

Attached Thumbnails

       

__________________
88 W124 3.0
96 R129 119eng
06 ML350
98 ML320 sold
02 CLK55 amg

can you check mixture adaptation with your scanner? did you blow smoke/air through the cylinder head air passages in each bank? i might take a close look at the air flow meter and the fuel pressure

I could not find a diagram of the air path thru the block to the heads and out the exaust but the air smoke does make it out the tail pipe.The adaptation is at 1.10

Attached Thumbnails

     

__________________
88 W124 3.0
96 R129 119eng
06 ML350
98 ML320 sold
02 CLK55 amg

I had that happen on my 97 E420, turned out to be a broken vacuum line to the air pump. Follow the line and see if it's that.

__________________
With best regards

Al

Thanx r.e.wing fc3s,I had a bad mass air flow meter that was bad completly open when you ohm it out,but I replaced it with a cheap ebay one might be a problem even the code for the maf went away.
I never checked the fuel pressure how can this cause a air pump malfunction?
I will ck it I heard it should be 50psi at the rail.
Thanx Alabbasi, they look good but I am replacing them now I just got the 10ft of line I ordered. John

__________________
88 W124 3.0
96 R129 119eng
06 ML350
98 ML320 sold
02 CLK55 amg

anything that throws of the air fuel mixture that the o2 sensors expect to see can set a c.e.l. if the car is running to rich from a bad regulator the air pump will not be able to add enough to the exhaust to make the o2 sensors recognize that the pump is flowing correctly.

I may have had a lean condition also at cold start idle. I had alot of symptoms at cold start idle of a air intake leak. When I removed the intake manifolds it appears to have been confirmed looks like it was sucking oil out of those center oil ports on the heads,and the gaskets were all wet.No water leaks heads are straight manifold also straight. Looks like it only did this cold. When the engine warmed up it was fine. (expansion)
Today I am going to see if the air flows thru both cyl heads for the air injection system.
Really not bad for 260k

__________________
88 W124 3.0
96 R129 119eng
06 ML350
98 ML320 sold
02 CLK55 amg

Glad I did not put on the intake manifolds yet! Alot of air comes out the left bank when I blow air in the air injection pipe.I turned the engine to many different positions to open different exaust valves to check the different air injection ports at 16 different ports but no air comes out of the right bank alot of air comes out of the left bank only, so no ports cloged on left side all ports cloged on right side! Odd I suspect a previous owner did the left side already so I will be pulling the right side head now.
What a shame the compression was so good at 180psi all cyl......................

__________________
88 W124 3.0
96 R129 119eng
06 ML350
98 ML320 sold
02 CLK55 amg