Ecu temp sender problem

[wongthecorrupter]

My chimaera has suddenly started to have a cold start issue,when its left overnite sometimes it refuses to start,it cranks over fine but smells like its flooding.I pulled the plug of the ecu temp sender and it fired up fine,so i thought get a new ecu temp sender fitted and job done or so i thought.My Car has been outside for a week i came to run it last nite and it started fine,great its fixed until i came to use it today and it wouldnt start again unless i pulled the ecu temp sender plug off.Any ideas chaps

[blitzracing]

By unplugging the sensor its open circuit, I think the ECU is smart enough to know its out of range, so it might throw the ECU into fall back mode and ingnore the sensor setting. A couple of simple tests need to be done on a stone cold engine. Use a test meter to check there is 4.5 - 5 volts across the temp sender connection in the loom with it disconnected, and ignition on. Also check the resistance of both temp senders (The second one is on the fuel rail) and check they are near the same when cold, as both have the same temp to resistance readings. It would be worth plugging in a fault code reader for a while as well having done an ECU reset (Your tests will have likely generated a code that needs to be cleared), and see if any codes throw up.

[wongthecorrupter]

blitzracing said:

By unplugging the sensor its open circuit, I think the ECU is smart enough to know its out of range, so it might throw the ECU into fall back mode and ingnore the sensor setting. A couple of simple tests need to be done on a stone cold engine. Use a test meter to check there is 4.5 - 5 volts across the temp sender connection in the loom with it disconnected, and ignition on. Also check the resistance of both temp senders (The second one is on the fuel rail) and check they are near the same when cold, as both have the same temp to resistance readings. It would be worth plugging in a fault code reader for a while as well having done an ECU reset (Your tests will have likely generated a code that needs to be cleared), and see if any codes throw up.

Thanks