Difficult Starting And Rough Running When Cold

[billyboney]

hi all,i have a 1999 petrol avensis which has developed a problem.its difficult to start when cold and runs really rough untill warm(about 10 mins).once warmed up its fine.im thinking its a sensor breaking down.its an old car and dont really want to spend a fortune on garage bills etc.i would be grateful for any advise,cheers andy

[Jamesbelfast]

It may be worth checking out the engine coolant temp., sensor/s and their electrical connections. If faulty the ECU may think the engine is always cold and doesn't adjust fueling correctly.:)

[billyboney]

It may be worth checking out the engine coolant temp., sensor/s and their electrical connections. If faulty the ECU may think the engine is always cold and doesn't adjust fueling correctly.:)

hi james,is that the sensor in the thermostate housing,cheers andy

[Jamesbelfast]

It may be worth checking out the engine coolant temp., sensor/s and their electrical connections. If faulty the ECU may think the engine is always cold and doesn't adjust fueling correctly.:)

hi james,is that the sensor in the thermostate housing,cheers andy

I ain't certain on your model but it's were I would begin hunting.:)

[igormus]

hi all,i have a 1999 petrol avensis which has developed a problem.its difficult to start when cold and runs really rough untill warm(about 10 mins).once warmed up its fine.im thinking its a sensor breaking down.its an old car and dont really want to spend a fortune on garage bills etc.i would be grateful for any advise,cheers andy

Andy

- sparks;

- MAF sensor (responsible to control fuel mixture before ignition);

- You probably have an over fueling effect due to MAF sensor is dirty and gives a wrong signal

- The engine coolant sensor is nor faulty -- if all is OK with fuel mixture then it is never mind for the engine when the driver starts it (at what temperature)Most probably you have poor spark to ignote the fuel mixture and this fuel film might to create short cut on the sparks leading that one cylinder does not work ---- this effect creates rough running.

Cheers/Igor