Another misfire thread W124 M111 2.2

[optimusprime]

I would first look at distributor ,rotor arm, 95% of problems are in the ht side, and even fuses in the fues box along with earth points , then vacuum,, any hoses split replace them so much of these engines need 100% vacuum to keep it running in tip top condition .

 

[Robbarr88]

I would first look at distributor ,rotor arm, 95% of problems are in the ht side, and even fuses in the fues box along with earth points , then vacuum,, any hoses split replace them so much of these engines need 100% vacuum to keep it running in tip top condition .

Cheers optimusprime think thats going to be the next job replace 100% of the vacuum lines just to eliminate that as source of a problem.

Thanks again.

 

[Robbarr88]

Just for reference can anyone tell me where the central locking vacuum feed would be isolated? The cars been fitted with electric remote central locking - so best to check the old unit has been isolated and not open ended, thanks again

 

[optimusprime]

Most are under rear seat awab .You will havre to look for it once seat is removed . The pump will be encased in foam ot box.

 

[Robbarr88]

Great stuff thanks again!!

 

[SMS]

How many cylinders are missing? If two check the ign pack/driver. Prone to failing.

 

[optimusprime]

SMS have you posted on the wrong thread ?

 

[grober]

I would first look at distributor ,rotor arm, 95% of problems are in the ht side, and even fuses in the fues box along with earth points , then vacuum,, any hoses split replace them so much of these engines need 100% vacuum to keep it running in tip top condition .

the M111 doesn,t have a distributor just two lost spark coils driven by the ECU power transistors- which can go faulty. Basically uses the same ht electronics as the six cylinder M 104 ENGINE. Don't think the 2 L M111 has the electrically adjusted inlet camshaft but if it does-- that another possible fault to check.

 

[optimusprime]

I was talking to a guy on the forum with a 2litre and got mixed up..

 

[grober]

Problem with cars that have experienced engine wiring loom problems is that certain ECU components may have been damaged. Even if the loom is repaired/ replaced these will remain to often give mysterious running problems. Repair/replacement may affect a cure but the unit needs to go to an ECU repair specialist for testing or repair.

 

[SMS]

Yes, the op has a misfire, helpful to know on how many cylinders.

 

[GP801]

Not sure how relevant this is to a 4 cylinder but if the basic system is the same as the M104 it may help. Many years ago our 280 developed a terrible misfire. Initially put down to HT leads and a dodgy coil pack but the issue quickly returned after a temporary cure. Turned out the dodgy coil pack had fried the ECU. Might be worth trying a known good ECU to see if it solves the issue.

 

[BlackC55]

What cylinder is it? Use a infrared thermometer on each cylinder and the coldest one will be the misfiring one.

Then see if you have a spark there. If you don't then concentrate on what can cause that.

 

[carat 3.6]

Sound like the throttle body harness to me. If the main engine harness was degrading the throttle body will have the same issue.

With the engine running move that part of the harness about and see if the running gets worse or improves.