Engine runs only 2 seconds

My Vento (Jetta) 95 1,8 does not work in cold weather. It starts and engine runs for 2 seconds, then dies. Installed a new coil but that did not solve anything. The computer at the shop did not record any malfunction in "normal" temperatures, but below 0 degrees Celsius (freezing point) it showed "ECU blocked". They reprogrammed the ECU, but the engine will still not start. Is it most likely that I have to replace the ECU or is there any malfunctioning connected components or bad connections that can cause these problems ?

My Vento (Jetta) 95 1,8 does not work in cold weather. It starts and engine runs for 2 seconds, then dies. Installed a new coil but that did not solve anything. The computer at the shop did not record any malfunction in "normal" temperatures, but below 0 degrees Celsius (freezing point) it showed "ECU blocked". They reprogrammed the ECU, but the engine will still not start. Is it most likely that I have to replace the ECU or is there any malfunctioning connected components or bad connections that can cause these problems ?
Earlier you said the engine would start and run for 2 seconds and then die. When it did this, was the engine speed very high? If so, clean the MAF sensor. Now, it appears that the engine will not start at all. Is this true or does it have the same sympton as before?

Earlier you said the engine would start and run for 2 seconds and then die. When it did this, was the engine speed very high? If so, clean the MAF sensor. Now, it appears that the engine will not start at all. Is this true or does it have the same sympton as before?

Thanks for quick reply

Just to make things a little clearer:

Nothing is changed after reprogramming the ECU. The symptoms are still the same.

During the 2 seconds of success, the engine speed is higher than normal, but not very much.

By the way,where is the MAF sensor located and what is its purpose ?

Thanks for quick reply

Just to make things a little clearer:

Nothing is changed after reprogramming the ECU. The symptoms are still the same.

During the 2 seconds of success, the engine speed is higher than normal, but not very much.

By the way,where is the MAF sensor located and what is its purpose ?

Mass Air Flow Sensor is located after the air box assembly in the air intake hose. It has a four wire connector. It's purpose is to measure the amount of air coming into the engine.

Mass Air Flow Sensor is located after the air box assembly in the air intake hose. It has a four wire connector. It's purpose is to measure the amount of air coming into the engine.

I cold not find any MAF sensor in my Vento, and after some investigation it was confirmed that the 95 mod. sold in Norway never had any. The source of my problems must be found elsewhere. But thanks anyway.

Problem solved, anyone who want to know who the culprit was ?

Someone, the former owner did of course not know anything about it, had removed the reading coil of the immobilizer from the ignition lock, dismanteled the ignition key and superglued its chip to the coil. I found the reading coil deep inside the dashboard. Sloppy work caused the cable to short circuit in cold weather. No wonder no fault finding diagram in the world could help me.