We have had our Kalos Blue from new which has been plagued with shuddering problems resulting in the engine management light coming on. The car is now 4 years old and still has problems.
From cold it shudders and car vibrates, giving the impression that either you have a defective spark plug or HT lead but this is not the case. We have had replaced the engine head off and rebored, 3 sets of HT leads, new plugs, new coil pack, drive shaft sensor all to no avail.
Sometimes you cannot get the car above 60mph when it does reach this the check light comes on and then it will run smoother for a couple of days before reverting back to the shuddering etc.
When put on the diagnostic scanner all it shows is there is a misfire which has been the problem throughout the cars entire life and we cannot narrow it down to one specific problem.
Any ideas on what this could be would be appreciated - even Daewoo couldn't figure it out when in warranty.
Kalos Blue engine management problems
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PrecisionBoost
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Well..... unfortunatly there are very large number of items which could be causing the problem.
Basicly it all comes down to fuel and spark.
You could have the injectors checked.... basicly they remove the injectors and then test them by pulsing them with a given fuel pressure to see how much fuel comes out over a period of one minute.
The can check all four against each other and the factory specifications.
If the injectors are fine you should replace the fuel filter (even if it's not the problem it's a good idea to do it once in a while anyways... I say every 50,000 miles... but other say as little as 10,000miles or once a year)
I would also check the fuel pressure to ensure that your fuel pump and fuel pressure regulator are working as they should.
So once the injectors, fuel pump and fuel pressure regulator are ruled out then the only other possibility is the spark.
Unfortunatly if the timing sensors ( crankshaft and cam shaft position sensors) are not working as they should or if there is some sort of electrical interference the ECU will get confused and fire the spark plug at the wrong time.
If you have a scanner I would look at the real time data as you drive and check the ignition advance..... I think it's usually around 8 deg of advance at idle (not 100% sure of that) and under load the advance should increase.
How far it will advance the timing depends on a number of issues such as coolant temperature, intake air temperature.
So it's important that these two temperature sensors be working correctly.
If it's missfiring it could be firing too far in advance (spark knock) or way too late when the exhaust valve is allready opening.... it could even be firing during the intake stroke instead of the power stroke if the cam shaft sensor is screwed up.
Do you hear any back fires when it's running bad like this??
If so you need to determine if the backfire is coming from the engine compartment (intake) or the exhaust
If it is a spark related issue that can be a real pain to diagnose since the ECU is in complete control of when the coil pack fires the spark plugs.
Loose electrical connections ( wires or connectors) can often prove to be very troublesome to find.
Basicly it all comes down to fuel and spark.
You could have the injectors checked.... basicly they remove the injectors and then test them by pulsing them with a given fuel pressure to see how much fuel comes out over a period of one minute.
The can check all four against each other and the factory specifications.
If the injectors are fine you should replace the fuel filter (even if it's not the problem it's a good idea to do it once in a while anyways... I say every 50,000 miles... but other say as little as 10,000miles or once a year)
I would also check the fuel pressure to ensure that your fuel pump and fuel pressure regulator are working as they should.
So once the injectors, fuel pump and fuel pressure regulator are ruled out then the only other possibility is the spark.
Unfortunatly if the timing sensors ( crankshaft and cam shaft position sensors) are not working as they should or if there is some sort of electrical interference the ECU will get confused and fire the spark plug at the wrong time.
If you have a scanner I would look at the real time data as you drive and check the ignition advance..... I think it's usually around 8 deg of advance at idle (not 100% sure of that) and under load the advance should increase.
How far it will advance the timing depends on a number of issues such as coolant temperature, intake air temperature.
So it's important that these two temperature sensors be working correctly.
If it's missfiring it could be firing too far in advance (spark knock) or way too late when the exhaust valve is allready opening.... it could even be firing during the intake stroke instead of the power stroke if the cam shaft sensor is screwed up.
Do you hear any back fires when it's running bad like this??
If so you need to determine if the backfire is coming from the engine compartment (intake) or the exhaust
If it is a spark related issue that can be a real pain to diagnose since the ECU is in complete control of when the coil pack fires the spark plugs.
Loose electrical connections ( wires or connectors) can often prove to be very troublesome to find.
2010 BMW 335D
1994 Opel Calibra 4X4 turbo ( C20LET 2.0L Turbo )
2002 Daewoo lanos
1994 Opel Calibra 4X4 turbo ( C20LET 2.0L Turbo )
2002 Daewoo lanos