Opel Vectra C GTS 3.2 Idle speed

[Stephan]

General Motors 54° V6 engine. (2014, July 16). In Wikipedia, The Free Encyclopedia. Retrieved 00:36, July 29, 2014, from http://en.wikipedia.org/w/index.php?title=General_Motors_54%C2%B0_V6_engine&oldid=617213011

Good morning,
before i start i want to excuse my bad english. My native language is german but i’ll do my best 😀

My car:
Opel Vectra C GTS, 3.2, 155kw
Engine Type in Germany Z32SE (I do not know if it was used in the USA. Wikipedia told me Y32SE. The base engine is the same. Z32SE was “emission optimized”. Only 1 throttle valve. 3 catalytic converters. However the first two catalytic converters [each bank has 1] were removed and the motormanagementsystem which monitors the lamdasensors behind the catalytic converters was reprogrammed and disarmed watching them.)
158 tkm (about 100000 miles)
The car has a LPG System (It runs better on LPG then on petrol but for testing reasons i only drive on petrol atm)

Problem:
Cold start runs fine but the rpm drops to fast to normal idle speed even the engine ist not warm. After 5 seconds. It does not sound well but runs stable. Als cylinders are working.
When the car gets on operation temperature the idle speed jumps. Like some cylinders misfire.
But only sometimes. Sometimes its perfect sometings annoying like hell.

What ive done so far:
I searched for wrong air with starter pilot. No effect. Seems to be sealed. I removed the plugs they all look well but i renew them with original Bosch. No effect.
Compression test was perfect.
I switched the lambda sensors. (The car has 4 and i changed them from the back to the front). No changes.
I cleaned up the throttle valve. No change. Was already clean therefore i service my car.
Maximum speed test was succesful. 160 miles an hour was reached with no problem.
Therefore the aiflow meter should work i think (tell me if i think wrong please).
I preform a pressure test on the exhaust. It is sealed.
I run ignition nozzle cleaner –> no change. However the car do the same behaviour if it run on LPG but not so strong.
Of course i checked the electronic System but no error reported. Nothing like missfire or somehting like that.
I think but i do not know for sure it has something to do withe the outside temperature. The airflow meter produced by bosch has an intake air temperature sensor in it. The degrees displayed look to high for me. Hotter air causes less petrol am i right? Could that be a problem? But is only 10 degrees to high from he outside temperature. Could that difference causes problems?
On the other hand removing the airflow sensor reduces power but has no running effect.

I do not know what to preform next and maybe the americans have an answer ;D Fire in all directions or please tell me if my thoughts are wrong.
Some people told me i have to live with that but thats not an option for me. It has to run perfect. But changing all parts without having an idea is ineffective therefore thoughts/hints are welcome ;D

Best regards,
Stephan

Topic

[EricTheCarGuy]

Given that the problem seems to be temperature related I would start by looking at the operation of the coolant temperature sensor. An easy check is to compare it’s temp to that of the intake air temp sensor when the engine is OFF and cold. The readings should be the same. Outside of that you’ll have to check the service manual for information on the resistance it’s suppose to have at a given temperature and compare your readings to see if they’re correct. More info on solving issues like this here.

http://www.ericthecarguy.com/faq/solving-automotive-performance-issues

Good luck and keep us posted.

[Stephan]

Thank you for helping me with my problem.

I did what i was told to do. However the coolant sensor looks ok for me. The car was standing in my garage for about 48 hours. Measurement was taken at complete cold engine with only ignition on.

COLD ENGINE VALUES:

Mass Air Flow Sensor,1.02 V
Mass Air Flow Sensor,0 kg/h
Intake Air Temperature,30 °C
Intake Air Temperature,3.16 V
Knock Control,Inactive
Fuel Tank Ventilation Valve,Inactive
Fuel Tank Ventilation Valve,0 %

Measuring blocks information:

Battery Voltage,12.2 V
Engine Speed,0 RPM
Ambient Temperature,21 °C
Coolant Temperature,24 °C
Coolant Temperature,3.44 V
Intake Air Temperature,30 °C
Mass Air Flow Sensor,0 kg/h
Normal Engine Operating Temperature,Inactive
Fan Control 1,Inactive
Fan Control 2,Inactive
Fan Control 3,Inactive
Oil Level,Normal
Engine Oil Level Status,Okay
Oil Pressure,Underpressure
Engine Oil Change Warning,Inactive
Cruise Control,Inactive
Cruise Control Tip Switch,O (off)
Vehicle Speed in Cruise Control Range,Inactive
Vehicle Speed,0 km/h
Brake Switch 1,Inactive
Brake Switch 2,Inactive
Clutch Switch,Inactive
A/C Pressure (Air Conditioning),580 kPa
A/C Pressure (Air Conditioning),0.92 V
A/C Relay (Air Conditioning),Inactive
A/C Cutoff Mode (Air Conditioning),System OK
A/C Information Switch,Inactive
Malfunction Indicator (MI),On
Service Vehicle Soon (SVS) Indicator,Off
ETC Limp Home Mode (Electronic Throttle Control),Inactive
B1S1 Air/Fuel Ratio (Bank 1 Sensor 1),Rich
B1S2 Air/Fuel Ratio (Bank 1 Sensor 2),Lean
B2S1 Air/Fuel Ratio (Bank 2 Sensor 1),Rich
B2S2 Air/Fuel Ratio (Bank 2 Sensor 2),Lean

WARM ENGINE MEASUREMENT 1 directly after stop engine running idle:

Measuring blocks information:

Battery Voltage,14.0 V
Engine Speed,645 RPM
Ambient Temperature,16 °C
Coolant Temperature,93 °C
Coolant Temperature,0.92 V
Intake Air Temperature,30 °C
Mass Air Flow Sensor,10 kg/h
Normal Engine Operating Temperature,Active
Fan Control 1,Inactive
Fan Control 2,Inactive
Fan Control 3,Inactive
Oil Level,Normal
Engine Oil Level Status,Okay
Oil Pressure,Normal
Engine Oil Change Warning,Inactive
Cruise Control,Inactive
Cruise Control Tip Switch,O (off)
Vehicle Speed in Cruise Control Range,Inactive
Vehicle Speed,0 km/h
Brake Switch 1,Inactive
Brake Switch 2,Inactive
Clutch Switch,Inactive
A/C Pressure (Air Conditioning),640 kPa
A/C Pressure (Air Conditioning),1.00 V
A/C Relay (Air Conditioning),Inactive
A/C Cutoff Mode (Air Conditioning),System OK
A/C Information Switch,Inactive
Malfunction Indicator (MI),Off
Service Vehicle Soon (SVS) Indicator,Off
ETC Limp Home Mode (Electronic Throttle Control),Inactive
B1S1 Air/Fuel Ratio (Bank 1 Sensor 1),Rich
B1S2 Air/Fuel Ratio (Bank 1 Sensor 2),Lean
B2S1 Air/Fuel Ratio (Bank 2 Sensor 1),Lean
B2S2 Air/Fuel Ratio (Bank 2 Sensor 2),Lean

Measurement about 1 minute later engine running at idle speed:

Measuring blocks information:

Battery Voltage,13.9 V
Engine Speed,642 RPM
Ambient Temperature,16 °C
Coolant Temperature,94 °C
Coolant Temperature,0.90 V
Intake Air Temperature,30 °C
Mass Air Flow Sensor,11 kg/h
Normal Engine Operating Temperature,Active
Fan Control 1,Inactive
Fan Control 2,Inactive
Fan Control 3,Inactive
Oil Level,Normal
Engine Oil Level Status,Okay
Oil Pressure,Normal
Engine Oil Change Warning,Inactive
Cruise Control,Inactive
Cruise Control Tip Switch,O (off)
Vehicle Speed in Cruise Control Range,Inactive
Vehicle Speed,0 km/h
Brake Switch 1,Inactive
Brake Switch 2,Inactive
Clutch Switch,Inactive
A/C Pressure (Air Conditioning),640 kPa
A/C Pressure (Air Conditioning),1.00 V
A/C Relay (Air Conditioning),Inactive
A/C Cutoff Mode (Air Conditioning),System OK
A/C Information Switch,Inactive
Malfunction Indicator (MI),Off
Service Vehicle Soon (SVS) Indicator,Off
ETC Limp Home Mode (Electronic Throttle Control),Inactive
B1S1 Air/Fuel Ratio (Bank 1 Sensor 1),Lean
B1S2 Air/Fuel Ratio (Bank 1 Sensor 2),Lean
B2S1 Air/Fuel Ratio (Bank 2 Sensor 1),Rich
B2S2 Air/Fuel Ratio (Bank 2 Sensor 2),Lean

Injetor Timing (warm state):

Measuring blocks information:

Injector Time,4.1
Ignition Spark Angle,1.8 °CA
Ignition Dwell Time,4
Calculated Pedal Position,0 %
Calculated Throttle Position,1 %
Knock Retard Cylinder 1,0 °CA
Knock Retard Cylinder 2,0 °CA
Knock Retard Cylinder 3,0 °CA
Knock Retard Cylinder 4,0 °CA
Knock Retard Cylinder 5,0 °CA
Knock Retard Cylinder 6,0 °CA

Lamda sensors warm state:

Measuring blocks information:

B1S1 O2 Sensor Heater (Bank 1 Sensor 1),Active
B1S1 O2 Sensor (Bank 1 Sensor 1),664 mV
B1S1 Air/Fuel Ratio (Bank 1 Sensor 1),Rich
B1 O2 Sensor Loop (Bank 1),Closed
B1S2 O2 Sensor Heater (Bank 1 Sensor 2),Active
B1S2 O2 Sensor (Bank 1 Sensor 2),703 mV
B1 Short Term Fuel Trim (Bank 1),-1 %
B2S1 O2 Sensor Heater (Bank 2 Sensor 1),Active
B2S1 O2 Sensor (Bank 2 Sensor 1),723 mV
B2S1 Air/Fuel Ratio (Bank 2 Sensor 1),Rich
B2 O2 Sensor Loop (Bank 2),Closed
B2S2 O2 Sensor Heater (Bank 2 Sensor 2),Active
B2S2 O2 Sensor (Bank 2 Sensor 2),742 mV
B2 Short Term Fuel Trim (Bank 2),0 %
Intake Manifold Valve 1,Inactive
Full Load Enrichment,Inactive
Catalyst Protection Mode,Inactive
Desired Engine Idle Speed,650 RPM
Idle Speed Modified,No
Idle Speed Offset,Inactive
Dec. Fuel Cutoff (Deceleration),Inactive
Vehicle Speed,0 km/h

again intake air and mass sensor about 3 Minutes later. Engine was idling in the garage.

Measuring blocks information:

Mass Air Flow Sensor,1.27 V
Mass Air Flow Sensor,11 kg/h
Intake Air Temperature,32 °C
Intake Air Temperature,3.03 V
Knock Control,Inactive
Fuel Tank Ventilation Valve,Active
Fuel Tank Ventilation Valve,18 %

For me the intake Temperature is stupid or wrong. But i do not have experience if 10 degrees wrong could cause such a difference at idle speed.
Opinions as usual welcome.

Hope my informations will help you.

[Stephan]

OK, i fixed it.

Sry for my expression but i was extremly pissed. I removed the engine.
I went to a friend of mine at the bosch development center and the ignition modules were checked. The Lmm values were fine however the intake temperature was wrong. I got a new single sensor.
The Lamda sesnors were operating normal.
I used my soldering bolt and replaced the sensor (less than 30 cents). I deconstructed the throtle valve completely and changed the electric motor. The throttl valves were polished.

I cleaned the injection nozzles ultrasinic.

I deconstructed the whole air intake system, cleaned it, and resealed it.
As i had working space i serviced the alternator with new coals and ball bearing.

I replaced the hydraulic lifters. Not expensive and easy to change at this state.
The oil pan was dismantled, cleaned and sealed. The whole engine was flushed. The valves and valve seats (do not know the right word) were polished however they looked fine.
I cleared the characteristic diagram and fired it up. I LOVE IT banana:
Thats it how engines have to run.

I only had the wrong oil in my garage. Stupid 5w30 low-viscosity engine oil. Has to be replaced this week.
New liqui moly engine oil was ordered…
However its no problem at all and propaply good changing the oil after the flushing chemicals.

The problem itself was not discovered by me and thats annoying. Ill have to live with it :S
After the oil change youll find me at the german Autobahn 👿

Thank you for trying to help me.
After all the work I think the problem was a bit off any type which could be possible.

[Author]

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