Technical High CO emissions

[Ricardogalpini]

Changed plugs leads and renewed the injector seals, plugs were not gapped correctly in comparison to new ones and manual. Fuel trim moves from -100 when pushing accelerator now but returns to 100 as soon as removing foot.

 

[varesecrazy]

Changed plugs leads and renewed the injector seals, plugs were not gapped correctly

Hence my comment about 5k miles...

So what gap did they have .. it looked vast... taken out the 'V' in some

 

[Ricardogalpini]

De-pressurised injector rail, removed.
All injector tips look dry as a bone, reconnected all injector leads and turned key to engage fuel Pp, 5 times fuel injector line repressured zero leak from injector heads.

Any ideas, I'm scratching my head

 

[Besa]

Did you check the fuel pressure regulator? Also try plugging the hose that comes from the evap canister and check the fuel trims while doing that.

 

[Ricardogalpini]

Just want to add idle is at 780rpm book says 810rpm with zero fluctuations on scanner.
Throttle body has integrated throttle position sensor and idle control stepper motor.

 

[MrMagoo]

Has it got a MAP sensor? What happens when you disconnect it?

 

[jackwhoo]

Besa has suggested disconnecting the evap canister pipe from the manifold , plugging the open port in the manifold and checking the fuel trim , Great idea.

Plus check the o2 sensor voltage while doing the above.

 

[koalar]

Again no oily deposit just grey and brown

All of them look like they need replaced, soot anywhere on a plug is not good, oil on the threads and gaps look wrong, put a feeler gauge on it, the burn is wrong, hence fuel going straight in to the exhaust.
Start with new plugs set at the correct gap, and hope after it is burning clean, that the Cat is ok after it burns/cleans all the excess fuel out.
Looking at the mot figures, it failed the first fast idle and just managed to get to the upper limit on the second fast idle for a pass, don't confuse a pass with good.
The plugs should look like Jackwhoo pics a nice clean burn.

Just want to add idle is at 780rpm book says 810rpm with zero fluctuations on scanner.
Throttle body has integrated throttle position sensor and idle control stepper motor.

mines 750 give or take. Fiats same engine cards are normally between 750-800

780 is fine.


questioned this way back as MOT specified 735 which is marginal on correct running

did you wait for the cars MOT or leave it with them.

 

[Besa]

Well I just looked it up and it seems to be a returnless fuel system. I don't know how does it regulate the fuel pressure but, you should really check the fuel pressure... It could be high.

Also some other questions and suggestions I could think of:

1. Does this car have a downstream(after the cat) o2 sensor? If there is, it's value seems to be stuck on zero at the scanner pictures you've sent. An engine running that rich, shouldn't both sensor see the rich condition?
2. Just because injectors aren't leaking, doesn't mean they are necessarily ok. Maybe they are internally sticking and overfueling. Get a long screwdriver or something similar and a multimeter. Put one end of the screwdriver on the injectors and the other to your ear and compare their clicking sound to see if they are consisted between all of the other injectors. And do the same comparison with the multimeter by checking the coil resistance of the injectors.
3. I know you look like a guy who wouldn't neglect oil changes but does the oil have a gasoline smell to it? If it's diluted by fuel, vapors could be finding it's way into the engine.

If everything fails you could try to introduce some small vacuum leaks and level out the fuel trim maybe? Just enough to get it inspetced...

 

[Ricardogalpini]

Just used the old metal rod to check for injector clicking and all seem to be turning on and off in harmony, will try and remove the evap canister pipe from the manifold and see what happens.

 

[jackwhoo]

Just used the old metal rod to check for injector clicking and all seem to be turning on and off in harmony, will try and remove the evap canister pipe from the manifold and see what happens.

Sorry if easier plug evap pipe at end away from manifold that will have same effect.

 

[Ricardogalpini]

Just removed the evap hose and short term fuel trim is now +30 Ltft is still -100 but now getting a normal bank 1 lambda reading as well. Will this reduce the emissions for a test?

 

[Ricardogalpini]

Sorry if easier plug evap pipe at end away from manifold that will have same effect.

Ran it plugged and unplugged both giving more or less the same readings but better in terms of lambda when unplugged

 

[jackwhoo]

Just removed the evap hose and short term fuel trim is now +30 Ltft is still -100 but now getting a normal bank 1 lambda reading as well. Will this reduce the emissions for a test?

If the voltage signal from the 02 sensor 1 is switching between about 0.2v and 0.9v at idle then there is a chance will pass mot.

But this is not a fix of the underlying problem.

Unplugging the evap pipe is introducing an air leak into the inlet manifold.

When you replaced the map sensor what brand was new one? Was it new or used?

What is the voltage reading of o2 sensor number 2 at idle and at fast idle- this voltage should not switch.

Cheers Jack

 

[Ricardogalpini]

If the voltage signal from the 02 sensor 1 is switching between about 0.2v and 0.9v at idle then there is a chance will pass mot.

What is the voltage reading of o2 sensor number 2 at idle and at fast idle- this voltage should not switch.

Cheers Jack

This voltage is now not changing unless acceleration

 

[Ricardogalpini]

Got the MAP sensor from fiat parts website, but looks unbranded

 

[Ricardogalpini]

I purchased it from AlfaFiat parts.Co.Uk

 

[jackwhoo]

This voltage is now not changing unless acceleration

I am sorry I am not sure which voltage you are referring too.

For any chance for passing mot o2 sensor 1 voltage must fluctuate between low and high at idle with engine warm.

When you see o2 sensor one voltage fluctuate low and high the ecu is maintaining the mixture correctly according to the signal it gets from the o2 sensor number 1 , which is before the cat.

O2 sensor 2 is after the cat and it's voltage should not fluctute very much at all it should look like a steady voltage. What is this voltage at idle.

 

[jackwhoo]

What part number is on invoice/packaging?

Do you have old map sensor?

 

[Ricardogalpini]

What part number is on invoice/packaging?

Do you have old map sensor?

Part number IS FT54254
I spoke to the dealer and gave reg and make and model when ordering