Stalling Saxo

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blueboy2001
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Stalling Saxo

Post by blueboy2001 »

My friend has a 98R 1.1 Saxo. When started from cold, unless he revs it for the first few minutes the revs drop to idle and it stalls. Once warm it runs fine.
I'm thinking the ECU is not switching to its cold running fuelling settings, but as the car is the base model there's no rev counter on it to indicate this easily.
Am I looking in the right place here, or is there something else I should check?
CITMAN
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Post by CITMAN »

I think the car has a problem with the coolant temp sensor which is connected to the ECU. This sensor tells the ecu whether the engine is hot or cold. If for example the sensor is telling the ecu that engine is hot when its actually cold, the ecu will adjust the settings for a hot engine i.e. mixture etc. And therefore the engine will stall as the mixture and idle speed arent high enough.
Hope this of some help.
blueboy2001
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Post by blueboy2001 »

Thats exactly what I was thinking, is there any tests I can do on this with a multimeter? Any values for cold or hot engines for instance? GSF don't list the part, so I'd imagine its going to have to be a dealer part which won't be cheap so I'd like to be sure before I swap it.
Also, does the same coolant temp sensor control the cooling fan, or is that controlled by another sensor?
wheeler
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Post by wheeler »

on a 98 its a seperate thermo switch on the radiator for the cooling fan,my guess would also be the coolant temp sensor,its the green one for the cold start,blue one is for the temp gauge/warning lamp.dont know the exact values off hand but it's an NTC type sensor so its resistance should de-crease the more it heats up.
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AndersDK
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Post by AndersDK »

Guess it's pretty much the same as the BX's "blue" ECU temp sensor located in head above clutch.
These are some 3Kohm varying according to temp. You may simply insert a potientiometer (5K/10K) instead to verify a stable engine run can be obtained. This would instantly proove the sensor good/bad.
These sensors ar known to simply open circuit after some y's.
assael1
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Post by assael1 »

Hi
your problum could be a faulty idle regulation stepper motor.
blueboy2001
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Post by blueboy2001 »

Would the above not show itself whenever the car is idling regardless of temperature?
Once its been running for 10 minutes its fine. I will check the sensor next week.
wheeler
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Post by wheeler »

at 40 degrees C temp should be approx 1000 ohms,@ 80 degrees C approx 300 ohms,@ 100 degrees C approx 200 ohms.
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