is something missing on my engine? w202

[lars-mad]

There are many possible reasons why your car is misfiring. The high tension circuits can fail coils or leads [ quite common] Low tension wiring insulation can go brittle due to engine heat and short out [ again quite common] this often happens after an engine rebuild when the wiring is disturbed. If the car was running OK for a time after the transplant I doubt you problem lies with the lack of connections to that sensor. Most likely to be the coils or associate circuitry. Its very difficult to advise on a car that's non original since its almost impossible to know what's been replaced and what's original. However experience would indicate problems with the IGNITION CIRCUITRY are the most likely causes of your problems.

okay should had have star diagnosis or something to read out the values ?
the problem with misfire does most often come at low revs like on a red light and when i then give more throttle at green light it misfires and go bad.. but if i push the pedal to the metal it works good.can it be the lambda sond? will buy new spark plugs and change the airfilter in the weekend i think and see if it helps and look for damage at the cables.. not funny when problems come :S

 

[lars-mad]

The engine management system controls both fuelling and ignition on these cars. While the engine ECU uses the crank position sensor CPS to monitor engine RPM and ignition firing the ECU uses the camshaft position sensor to fine tune fuel injection timing in relation to valve opening. In an engine with fixed valve timing the relationship between crank and camshaft position is fixed via the timing chain and sprockets. However in engines with variable valve timing such as the 111 engine [ inlet only] this relationship can vary. Hence the need for the fuel injection system to know more exactly when the valves open. It might explain your symptoms. However if the engine doesn't have variable valve timing- some 180's don't - then this parameter is not strictly required so perhaps explains why the car still runs without it.
Best to get it wired up again.

the engine is a 111 940 cant be from a c class i cant find it in the haynes book

 

[grober]

The M111.940 ENGINE was used in the W124 E200 from 92-95

The M111.940 is a 2.0 L (1998 cc) 16-valve engine with bore and stroke of 89.9 x 78.7 mm and compression ratio of 9.6:1. It produces 100kW (136hp) of power and 190 N-m of torque.

It employs the Siemens PEC/PMS (Pressure Engine Control) management system, which integrates fuel and spark management.
It is a speed-density type of system, as mixture formation is dependent on RPM, TPS angle, and manifold pressure (MAP).
Injectors work in pairs (idle, part load), or altogether (full-load).
It uses 2 ignition coils and no ignition distributor. Cylinders are fired in pairs (dual fire) - 1 and 4 together, and 2 and 3 together.

Has it got a variable timing inlet camshaft?

 

[Ian B Walker]

Not sure if this has been covered and apologies if it has. Some 111 engines do not have an Air Mass meter. If the subject car is one of those then the bit you say is missing is the cam position sensor. However I see it in your picture and wonder if at some stage has the head been changed? Has someone put on a Cylinder head off another engine because of unavailability and to seal the engine left the sensor in place?

 

[lars-mad]

The M111.940 ENGINE was used in the W124 E200 from 92-95

The M111.940 is a 2.0 L (1998 cc) 16-valve engine with bore and stroke of 89.9 x 78.7 mm and compression ratio of 9.6:1. It produces 100kW (136hp) of power and 190 N-m of torque.

It employs the Siemens PEC/PMS (Pressure Engine Control) management system, which integrates fuel and spark management.
It is a speed-density type of system, as mixture formation is dependent on RPM, TPS angle, and manifold pressure (MAP).
Injectors work in pairs (idle, part load), or altogether (full-load).
It uses 2 ignition coils and no ignition distributor. Cylinders are fired in pairs (dual fire) - 1 and 4 together, and 2 and 3 together.

Has it got a variable timing inlet camshaft?

how do i identify if it has one?

Lars

 

[lars-mad]

Not sure if this has been covered and apologies if it has. Some 111 engines do not have an Air Mass meter. If the subject car is one of those then the bit you say is missing is the cam position sensor. However I see it in your picture and wonder if at some stage has the head been changed? Has someone put on a Cylinder head off another engine because of unavailability and to seal the engine left the sensor in place?

much possible i do not know the last owner said the engine had been rebuilded with parts from the old 180 and the 124 engine that is in the car
just want it to run the way it should as i feel i have been screwed with a car with much problems :S
demister do not work the heater is working but at variable speeds++++ and a lot of smaller electric problems like the gas gauge is working and not working so someone has been screwing around

also the abs is working sometimes not working sometimes

 

[grober]

Intermittent ABS and IDLE PROBLEMS can be caused by a faulty OVP relay due to dry joints. They can sometimes be repaired by resoldering the small circuit board inside the can. The camshaft timing adjuster--if you have one---- will look like the cylindrical metal unit bolted to the front of the cylinder head in the picture [ may be very slightly different to the picture as its a 6 cylinder engine ] but should give you an idea what to look for.

 

[lars-mad]

Intermittent ABS and IDLE PROBLEMS can be caused by a faulty OVP relay due to dry joints. They can sometimes be repaired by resoldering the small circuit board inside the can. The camshaft timing adjuster--if you have one---- will look like the cylindrical metal unit bolted to the front of the cylinder head in the picture [ may be very slightly different to the picture as its a 6 cylinder engine ] but should give you an idea what to look for.

ovp relay is ?

 

[Nasco12]

I believe it stands for Over Voltage Protection. Not a clue what it does.

 

[mikestrivens]

clue is in the name. It protects the sensitive electrics from over voltage. They often fail due to dry joints on the pcb. Easy to remove and with a fine tipped soldering iron can easily be fixed.

 

[grober]

HERE'S LINK TO A HOW TO REPAIR A RELAY N10 Relay, Soldering Repair, Wiper - Indicators & Hazards - Rear Window Demister. - Mercedes-Benz Owners' Forums
There are lots of threads on the OVP just type in OVP in the forum search box.
here's one example http://www.mbclub.co.uk/forums/electronics/54305-ovp-relay.html
The OVP is usually located behind the battery and can be identified by having 1 or 2 fuses on the top.

 

[lars-mad]

will check it up but it cant be the snow that makes bad contact on one of the abs sensors?

 

[grober]

will check it up but it cant be the snow that makes bad contact on one of the abs sensors?

You are correct. Its entirely possible that some form of wheel sensor malfunction might cause the ABS light to come on. I suggested the OVP because you have problems with the engine also. The OVP supplies the engine ECU, the rotary idle bypass valve, [ if fitted] and the ABS control unit.

 

[lars-mad]

You are correct. Its entirely possible that some form of wheel sensor malfunction might cause the ABS light to come on. I suggested the OVP because you have problems with the engine also. The OVP supplies the engine ECU, the rotary idle bypass valve, [ if fitted] and the ABS control unit.

is the ovp relay green?

 

[lars-mad]

is this the ovp relay?

 

[Peetronas]

The engine management system controls both fuelling and ignition on these cars. While the engine ECU uses the crank position sensor CPS to monitor engine RPM and ignition firing the ECU uses the camshaft position sensor to fine tune fuel injection timing in relation to valve opening. In an engine with fixed valve timing the relationship between crank and camshaft position is fixed via the timing chain and sprockets. However in engines with variable valve timing such as the 111 engine [ inlet only] this relationship can vary. Hence the need for the fuel injection system to know more exactly when the valves open. It might explain your symptoms. However if the engine doesn't have variable valve timing- some 180's don't - then this parameter is not strictly required so perhaps explains why the car still runs without it.
Best to get it wired up again.

Hello, your quote is so great, I have the same issue with my c180 1993, the car’s wiring installation is a mess and there are couple of sensors disconnected and it’s hard to get them right, as well as the camshaft adjuster and camshaft position sensor CPS, so I’m in trouble in figuring out these as I cannot reach the 2 pins connector for the camshaft adjuster neither the 1 pin head cover connector for the CPS. What it looks to me is like these are cut off and I’m about to find the source for it. I think this is for better car performance but I have some trouble with the car on the first start when is cold, it shuts off after 20-30 seconds each start when idling, it requires to rev up ~3000rpm for like 30-40 seconds so after that the car calms down and works smoothly.
I have searching for camshaft adjuster wiring diagram and I end up with disconnecting the ECT( emgine coolant temp sensor, in my car was wired by a mechanic but wasn’t a factory) so I have unwired and find that the 2 wires ( 1 green/redare, 2 brown/yellow) same as for the camshaft adjuster so I connected to it, unfortunately the car goes worse. Big symptom: first start won’t start either, just keep cranking forever so I got it how start anyway, start up the car and when cranking like 2-3 seconds turn off the ignition so then wait 2-3 minutes, start again and same, third try wait for 5-6 minutes then it will start up but if you don’t have throttle it up the car will shut off, it requires like a long rev, ~3000rpm for like a few minutes. I will reconnect the ECT like it was before but still the car needs to be fixed for better first start.
I’m so confused and I need help, will appreciate it so much

 

[grober]

 

[wrdcc01]

Here's a picture I grabbed from the internet showing the cam sensor wire appearing just near the flash sticker.

 

[Peetronas]

View attachment 121225

Thanks for this, was really helpful and I found it was my mistake to disconnect the coolant sensor, reconnect it back so the car was working smoothly. Hopefully I get rid of the car so I sold out haha. Much appreciate your reply looking forward

 

[Peetronas]

Thanks for this, was really helpful and I found it was my mistake to disconnect the coolant sensor, reconnect it back so the car was working smoothly. Hopefully I get rid of the car so I sold out haha. Much appreciate your reply looking forward

Moreover I’m so sorry for the late response