Engine starts but stops immediately after tune up

chashy · July 12, 2017

Hi guys,

I have been using this forum for a while but this is my first post. I did an engine tune up on my suzuki swift HT51s model two days ago. The mechanic replaced the plugs. Everything was fine until yesterday morning. The car started but the RPM needle quickly comes down to zero and the engine stops. I accelerated the car to make sure the needle does not drops but when I release the accelerator peddle the engine shuts down. After couple of attempts the engine starts and runs as usual. I felt this today morning as well. What could be the problem?

Thank you in advance.

Crosswind · July 12, 2017

Just check whether everything is tightened properly - the airflow sensor, the plugs, plug wires (if any),

Davy · July 12, 2017

Could be due to the fact that your ECU is still learning. This is normal and driving your car for a while should solve the issue because it takes a few kilometres of driving under different conditions for the ECU to re-learn.

If the issue persists, it could be that your Idle Control Valve (or Idle Air Control Valve) is sticking. Our mechanics have the habit of spraying cleaning solvents directly at IACVs and this can ruin them - especially plunger type ones.

The Stig · July 12, 2017

Was your maf cleaned by any chance. If you know what the maf is disconnect the plug and see if the car runs fine.

Maf is in between your airfilter and throttle body.

chashy · July 18, 2017

On 7/12/2017 at 5:17 AM, Davy said:

Could be due to the fact that your ECU is still learning. This is normal and driving your car for a while should solve the issue because it takes a few kilometres of driving under different conditions for the ECU to re-learn.

If the issue persists, it could be that your Idle Control Valve (or Idle Air Control Valve) is sticking. Our mechanics have the habit of spraying cleaning solvents directly at IACVs and this can ruin them - especially plunger type ones.

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As many of you suggested including Davy, I also thought ECU is still learning. Now, it starts without a problem in the morning. Yesterday, same issue came when I parked the car after driving for one hour and tried to restart it. The rpm just dropped to zero and engine stopped. If I keep the accelerator pressed and hold for some time the issue disappears. Could this be usual as well? Thank you.

Davy · July 18, 2017

On 7/18/2017 at 12:08 AM, chashy said:

As many of you suggested including Davy, I also thought ECU is still learning. Now, it starts without a problem in the morning. Yesterday, same issue came when I parked the car after driving for one hour and tried to restart it. The rpm just dropped to zero and engine stopped. If I keep the accelerator pressed and hold for some time the issue disappears. Could this be usual as well? Thank you.

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The ECU re-learn shouldn't take this long IMO. Get your IACV checked as mentioned above. It might be getting stuck or malfunctioning. When you try to maintain a stable RPM using the accelerator pedal, does the engine idle smoothly, or is it rough?

Since you say cold starts are normal, does your RPM rise to about 1500 and slowly settle down to normal (i.e 700) when the engine becomes warm?