2003 1.4 8 valve, running rough

HI, I have a 2003 1.4 8 valve c3, It is running like a bag of nails, turn the key and it will start, runs really rough for about 30 seconds and then sort of clears, I have changed all these parts from a good running car to find the problem, changed the injector rail complete with injectors
Maf sensor
Throttle body
sensor on the exhaust manifold
It came up with a fault code P0170
Changed a valve electrical I think it is called the canister valve.
I have taken the Plugs out and they are Black as the ace of spades
cleaned them put them back and it was better for a short while, and then back to the same.

Not a lot left now,
Any idear's

Paul

paullap wrote:I have taken the Plugs out and they are Black as the ace of spades

Black as in oily or carbon/sooty?

Have you changed the air and fuel filters?

paullap wrote:It came up with a fault code P0170

paullap wrote:I have taken the Plugs out and they are Black as the ace of spades
cleaned them put them back and it was better for a short while, and then back to the same.

They are getting coked up because the P0170 is indicating a fuel trim problem.

Check for air leaks on the inlet side (along with the things you have already done), and

Missing Lincs wrote:Have you changed the air and fuel filters?

there is even mention of an inlet valve problem - may be worth checking valve clearances if everything else is tested to be ok.

paullap wrote:I have taken the Plugs out and they are Black as the ace of spades
cleaned them put them back and it was better for a short while, and then back to the same.

Hi Paul, next time they are out, would it be possible to take a picture (or more) and attach it?

Hi thanks for the replies, plugs Black and sooty. I put lexia 3 on it and something came up about a purge canister. I cant find out where this is. The plugs look like the chimney stack soot. air leak seems likely to me, The maf sensor detects it lean, and then pumps more fuel in, Does this make sense?. or am I barking up the wrong tee. I drove it about 50 miles and it did seem very heavy on fuel.

Regards


Paul

paullap wrote: I put lexia 3 on it and something came up about a purge canister. I cant find out where this is.

I would say its going to be connected to the purge canister valve which you changed?

paullap wrote:Changed a valve electrical I think it is called the canister valve.

You can screen capture the lexia diag screens for reading later (Alt and Prt Sc, then paste into a new image) or use the screen cap option in lexia itself.

Hello again, There is not a lot else to change, I have now taken the car to my sons house with the Lexia3 diagnostics, He will understand the live readings a bit more that me. He can check all the readings from each sensor, I am not sure how he can check for a air leak on the inlet side, I hope that I am not looking at a ECU problem as many of these c3 do, my brother is a dealer and has had many c3 with ECU problems, never one with this fault though. how would you know if the ECU is not working correctly?. I will not give up on this car, I will buy another if it is the last resort and slowly change everything until i find the problem.

Thanks

Paul

paullap wrote: how would you know if the ECU is not working correctly?.

You can only put the fault down to the ECU after you have checked the sensors that input the data, the wiring harness and connectors that convey the data and the output devices with their associated wiring and connectors that are driven buy the ECU.

You could swap ECU and BSI over to a known good car, therefore testing all the input/output and wiring in one go.

The other way is to simulate all those inputs and outputs with a computer and electronics and do it all on the bench, which is how I would imagine companies like BBA Reman test all the equipment they have to repair.

If you are testing by substitution be aware that you are not being tricked by having two faults that cause similar problems and are only changing one part at a time.

paullap wrote: I have now taken the car to my sons house with the Lexia3 diagnostics, He will understand the live readings a bit more that me. He can check all the readings from each sensor,

Lexia 3 is great for reading live data, it can even update ECUs if there is one to do. If you can screen capture the live data, you are welcome to attach the images to your posts, which can show other exactly what data you are getting.

paullap wrote: I will not give up on this car, I will buy another if it is the last resort and slowly change everything until i find the problem.

Just the act of disconnecting and reconnecting the connector can clear a faulty high resistance connection

A bit more info, my son has been doing some diagnostics, and came up with the code P0603, here is a link that explains what it means, these cars are getting beyond a usual mechanic, you need to be a electrical technician,

https://repairpal.com/OBD-II-Code-P0603


Paul

paullap wrote:A bit more info, my son has been doing some diagnostics, and came up with the code P0603, here is a link that explains what it means, these cars are getting beyond a usual mechanic, you need to be a electrical technician,

https://repairpal.com/OBD-II-Code-P0603


Paul

I would go with what lexia 3 gives as the description, test procedure and repair rather than a generic 'ECU' error. Its not the cheapest to change ECU, BSI and Keys, so getting it right is important.