Hello all,

[new member]

 

I have an interesting issue with my MPI 1.3 (1998) Felicia the below described issue occurs when the engine is cold.

When the outside temperature is below approx. 15°C, immediately after the engine start the idle rev. is 800-900 rpm. The engine has a no lack of power and runs smoothly.

However when the weather warms up and the outside temperature is over approx. 15°C, immediately after the engine start the idle rev. is 1200 rpm. The engine has a lack of power until the coolant temperature reaches approx. 70°C.

There is no fault code. The air temperature and coolant temperature sensor looks OK-I measures the resistance of those sensors.

I cannot figure out what causing this anomaly.

I will appreciate your help.

Thanks,

 

skoda 007

1 hour ago, skoda007 said:

The engine has a lack of power...

Describe how you tested for that and detail any other signs related. Remember you have full access to your car to observe, hear, and diagnose. We don't. For odd engine issues like yours, the more details you offer, the better.

 

Do you have a VAG-COM 409 interface? If yes, record the engine parameters with it (VagScope) from engine cold start to warm up then share the log file to tell you what is wrong. We need evidence to decide. The alternative is a blind guessing game (CTS, TB, O2 sensor, lack of fuel, etc.) based on statistics.

Hi RicardoM

 

Thanks for your reply.

Recently I read out 00537 lambda-lower limit.

Long time ago I also found:

00516 closed throttle idle position switch F60 29-10 short to ground intermittent

00537 shareware version to decode all DTC's 19-10 please register

 

I measured the temperature sensors resistance and compared with the values I found in Skoda service manual.

30 °C 1.5-2kΩ

80 °C 275-375Ω

Other syndromes:

-couple times the engine did not started when it was hot, than jumped on when the temperature of the coolant dropped to approx. 70 °C

-few times played up when the engine was cold-did not start. Swapped the coil pack- did not help. Than swapped the spark plugs. When I removed the spark plugs I could not smell petrol. Fit an another set of spark plugs than I used before. Than the engine fired up. The spark plugs had only 500-1000 miles and the coil pack was not faulty either as I tried it since.

-very rarely when I turn the ignition key to 1st position and the fuel pump is activated for few seconds, 3-5s I can hear a very strange noise coming from the engine, like something pressurizing- actually the fuel line does

I will check if I have a Vag Scope function active and will try to map the engine.

PS: Friday I changed the fuel filter.

 

Many thanks

 

 

Hello RicardoM,

Please could you advise which modules should I record by Vag Scope. Looks I can choose 3 modules.

Thanks

Use VC-Scope from this page. It is easier to work with than VAG-Scope you have.

Normally you would record Group 001.

Hello RicardoM,

 

Managed to map some data-please note attached.

Thanks

LOG-01-xxx-003-004.CSV

Your log has 1,456 bytes. It is way too short.

Hello RicardoM,

 

Please note attached new log file.

Thanks.

LOG-01-002-004-005 3-15.CSV

I can't see anything wrong on this log. But on the other hand there isn't recorded live data of the oxygen sensor. Try to record Group 001, 007, and 011.

Hi RicardoM,

 

Please find attached the log file of groups 1, 7 & 11.

Thanks 

LOG-01-001-007-011 3-16.csv

The graph looks ok. But I don't understand why do you keep playing with the accelerator pedal during test. Stop it.

 

For now I recommend cleaning the throttle body. Clean the MAP sensor too.  Then perform a throttle body reset.

 

Look for vacuum leaks, check vacuum hoses and the gasket below throttle bod.

Hello RicardoM,

 

Thanks for the log review. I did the test whilst driving. That's caused the variation in rev. Thought to do it in load mode. Shall I repeat and log constant revs?

Will perform the recommended checks.

Thanks.

 

One more thing. Check if there are holes in the exhaust manifold / pipes before oxygen sensor.

Hi Ricardo,

 

Inlet and the outlet has no leaks.

 

Hi Ricardo,

 

Please could you have a look on the lambda frequency-please find attached vag measurement. Looks that the frequency is the same at 900 and 3200 rpm. Should the frequency raise with rpm?

Thanks. 

The frequency has nothing to do with the RPM of the engine.What is important is the amplitude of the signal varies approximately from 0.1 V to 0.9 V.

Have you cleaned and reset the throttle body as indicated?

 

 

Hello Ricardo,

 

Thanks for the reply and tutorial video.

Tried to reset the throttle body via vag-basic settings, group 098, but no ADP Run displayed. Also tried means block, 098, switch to basic settings.

I am not sure if I managed to reset it.

 

Use the free software Motordiag SIMOS Manager 1.53. Download it from here

Your existing cable should work with it.

Hello Ricardo,

 

Thanks for the link.