Engine stop rolling
 

A summary of the circumstances and the verifications already performed my car (MG ZT 190 2.5l V6 ESS (2001)):
Down for 2 months.
Circumstances of failure:
Along the way, loss of power, the motor signal is displayed on the dashboard, followed by a gradual deceleration to a stop the engine. Can not restart.

Here are the previous investigations:

- I first thought of fuel starvation -> by filling 20 liters remained in the tank
- The candles were black and wet -> certainly drowned due to different misfire. I cleaned.
- The relay and fuses associated with the fuel pump -> Ok
- I listened to the pump through the tank -> Ok
- The pump seems to work correctly -> Key in position 1, you can hear turn
- Checking for gas to the injectors -> By disconnecting the supply line, key in position 1, I can gather from 20 to 25 ounces of gasoline
- Check the fuel filter without removing the filter but an attempt to pose an orange collar attaches the filter to set a default pressure -> Failed filter because my model is not compatible with the default . The orange clip is for sale ... ;)
- Checking the crankshaft sensor -> I replace against a new but without effect.
- Verification of probes using a multimeter -> after cleaning and attempt to repair the lambda sensor with a torch, it gives "10 ohms" each. In truth, I do not even use a multimeter ... I have finally replaced by new probes
- Check sensor idle -> complete cleaning and change of the membrane (pending receipt of a new sensor)
- Check intake manifold -> Do not seem dirty, just a little too fat for my taste in the engine cylinders butterflies
- Check the air pressure sensor and temperature -> Thorough cleaning (eventually, I gave a new sensor)
.... etc.

Good short, I managed to restart the engine using the accelerator at the same time. But the problem is that I do not idle the engine. I have to keep the foot on the pedal and keep playing with the accelerator. It releases a lot of smoke at the back and at one point even accelerating the engine floods. And impossible to restart the engine whines again.

I initially perform diagnostics using the diagnostic function on-board the vehicle.
Here are some test results:

Engine off and key in position 1

5.0-Average Power 120 = 12 liters / 100 km
5.1-Battery remaining 247 km in
6.0-0296 fuel level ...
6.1-Overall fuel ----
8-Value in HEX 1 "£" 8
9.0-Battery 12 V 120 =
10.0-Code 56 countries
11.0-unit system FdFC07
Errors in memory 14.0-(14.0-> C78100), (14.1-> F48400), (14.2-> 000 000) (14.3-> 000 000) (14.4-> 000 000)

Then I has a diagnostic device and the ELM 327 Here are the results I got:

Here some data it cold, in switch position 2:

Freeze Frame Data

Fuel system 1 status OL
Fuel system status 2 OL
Calculated Load Value 48.2%
Engine Coolant Temperature 21 ° C
Short Term Fuel Trim Bank1-0.0%
Short Term Fuel Trim-Bank3 10.9%
Long Term Fuel Trim-Bank 1 -8.0%
Long Term Fuel Trim Bank 3-10.9%
Short Term Fuel Trim Bank2-0.0%
Short Term Fuel Trim-Bank4 12.5%
Long Term Fuel Trim-Bank 2 -8.0%
Long Term Fuel Trim-Bank 4 12.5%
Intake Manifold Absolute Pressure 83kPa
Engine RPM 4480rpm
Vehicle Speed ​​Senor 0km / h


Pending Trouble Codes

P0300 Random / Multiple Cylinder Misfire Detected (random misfire detected)
P0172 System Too Rich Bank 1 (Mixture too rich line 1)
P0175 System Too Rich Bank 2 (Mixture too rich line 2)
P0500 Vehicle Speed ​​Sensor "A" (the vehicle speed sensor - circuit failure) -> E waiting to receive new front axle sensor

99kPa inlet pressure tubure
Ignition advance deg 9.5 °
Absolute position of the throttle 11.37%
O2 sensor voltage channel 1 sensor 1 0410 Volt
O2 sensor voltage channel 1 sensor 2 0410 Volt
O2 sensor voltage channel 2 sensor 1 0410 Volt

Remains to be verified:
- The fuel pressure to the injectors -> problem, I do not have a compression tester
- The beam -> Waiting ;) reception
-. Etc. ..

That's where I am ...

My problem is that the air / fuel mixture is too rich and the car does not idle:

I changed the oxygen sensor, pressure sensor and temperature
I cleaned the sensor and idle changed the membrane
I cleaned the spark plugs

When cold, it starts quickly, there are a lot of white smoke with a smell of gasoline but does not idle

Someone has an idea;)?

Cambelt jumped a couple of teeth?

@ kaiser :
it is possible but how do we know?

What are the consequences if this is the cause of the failure
and are we repairable?

I would firstly check the belt by having a look at it.
Secondly stop engine in safe mode with pin through flywheel.
Then take off the back covers and check if the markings on the secondary sprockets are in line. If correctly timed all marks must align.
Depending on the jump, if small most likely no damage, if larger, bent valves.

However, if it has happened, why? Most likely a tensioner or an idler wheel.

Have the belts been replaced? how much mileage, age??

Only the main belt was changed 2 years ago when I changed the water pump. 20,000 kms only.
if no the car totaled 255,000 kms, 11 years old

The danger comes rather from the secondary timing belts. They don't have a tensioner and I am very sure that inspecting them will scare you. I've changed mine after seven years and 120k km and they were loose. Age kills them more than mileage.

The belts at the rear are very short and run between two equally big sprockets, and they don't need a tensioner.
They are not likely to jump a tooth, unless the teeth start wearing off.
If the teeth have started separating, however, all bets are off.

If you compare the rear cambelts/pulleys configurations of 820 and 75 you'll notice an improvement: a vibration damper. It was not placed there for nothing, it is because the exhaust pulley tends to oscillate. Judge by yourself what happens with a loose belt at 50 or 100 Hz. (or 73.235, pick your own value).

What about an idler wheel?