Technical 20V Marea starting problems

[20VMarea.Weekend]

My 20V Marea has an intermittent starting problem where by every now and then it takes ages to start... Seems to start fine from cold each morning but it is when it has gone for a short journey and then you try starting it after going into the shops it wont start.... Nearly fires up initially and then just turns over and over.... Seems to flood pretty quickly..!!

I think it is the Coolant Temp Sensor that is sending a COLD signal to the ECU and forcing the injectors to fire too much fuel in as for a cold start instantly flooding the warm engine....!!??

I am not sure where the sensor is though but have narrowed it down to one of two possibilities.... There is a sensor that screws directly into the passenger side end of the engine block that has a single wire connected to it and also a sensor that screws into the top of the water thermostat, this has a 2 wire plastic connector on it..>!! Which one is it..??

As an aside, I have cleaned the throttle body housing and the Idle Speed Control Valve and all are clean and the idle is now more consistant but occasionally the revs still go up to nearly 2000rpm and then drop back down....!!

Once started she runs really smoothly... £108k miles and going strong....

Any one out there able to help..??

Cheers

 

[jug]

its the crank sensor. your description has all the classic signs of crank sensor failure. thankfully it isnt too difficult to replace, and not too expensive either.

 

[20VMarea.Weekend]

Thanks for the reply..... I will get onto my local FIAT parts guys tomorrow and let you know how it goes..... Does not look too hard to change...

 

[20VMarea.Weekend]

Just called FIAT.... They want £88.00 for this...!! Any suggestions where I can get one at a sensible price..??

 

[jug]

your local motorfactor will be much cheaper.

 

[20VMarea.Weekend]

Managed to read the ECU at work today.....

2x fault codes listed....

45 COOLANT TEMPERATURE SENSOR CIRCUIT
22 CAMSHAFT CONTROL RELAY CIRCUIT

Coolant temperature reading all over the place. jumping around between 30 and 80C... Pull off the temp coolant plug and the open circuit reading is 80C..!! Dodgy wiring / connector / sensor...?? Have ordered a new Coolant Temp Sensor and will see if the readings settle.....

Camshaft control relay circuit seems to be associated with the Camshaft solenoid that changes the intake cam timing which as far as I cam see is also effected / controlled by water temp....... Solenoid seems to activate OK....

Reset the faults and 45 Coolant temp came back pretty much straight away....

 

[EI4GGB]

also use a bit of spray contact cleaner (switch cleaner) on the plug and connections on the coolant sensor, because often they get contaminated with coolant and anti-freeze residue, which corrodes the connections..

 

[20VMarea.Weekend]

OK... Finally a sunny day and some time to swap both the Coolant Temp Sensor and the Crankshaft Sensor....

Coolant Temp Sensor piece of cake.... Removed the air intake resonator box and access to sensor on the thermostat really easy....

Crankshaft sensor... Not so easy...... Took a while to locate as pretty well hidden... The old one came out easy ( Apart from access to the wiring connector ) but getting the new one in was a pig....!!! The O ring seal would not allow the new one to fit in very easily at all.... Eventually it went after lots of wiggling and twisting.....

Will reconnect the ECU reader next week, reset the ECU errors and see what happens then.....

Fingers crossed the intermittent starting problem has gone...!!!

 

[20VMarea.Weekend]

Car has been running perfectly for the last week... Starts first time every time and is much smoother to drive around town.... Job done....!!!