Hi Guys, 

 

I have the 1.4 TSI Twincharged unit in my ibiza cupra. I hope you dont mind me posting here!

 

The engine was replaced with a fresh rebuilt unit a little over a year ago. Since then it has been running great, I recently fitted a sports CAT downpipe, larger intercooler, And got a stage 2 REVO MAP. Still running Great!

 

But I have failed the MOT on too high CO and HC at Idle, at 2500 rpm the levels were pretty clean.  I cant quite figure it out, I first thought it could be the CAT, but i made sure it was hot before teh second test and it made no difference. The car is definetly over fuelling / running rich at idle. Could it be the injectors sticking/ leaking? 

 

Very grateful for some help. 

 

 

What was the last MOT like before the mods? I think I'd be starting there with troubleshooting.

8 minutes ago, chimaera said:

What was the last MOT like before the mods? I think I'd be starting there with troubleshooting.

 

Was MOT this time last year - passed no problem. But that was also before the engine was swapped. 

There is another recent thread worth reading with similar issue 

 

Possibly your remap is running to lean on idle?Was it remapped before last years mot? The map might possibly be running too rich...… Other than that we all know these engines run rich on idle for 30-45 seconds from start up. Has your MOT tester let the car idle for long enough?

 

Sports cat should pass an Mot, Each to their own however I've not heard many good things about revo remaps for these engines.

 

 

 

 

Edited 8 May, 20206 yr by Mickmartin

 

2 hours ago, Mickmartin said:

2 hours ago, Mickmartin said:

Possibly your remap is running to lean on idle?Was it remapped before last years mot? The map might possibly be running too rich...… Other than that we all know these engines run rich on idle for 30-45 seconds from start up. Has your MOT tester let the car idle for long enough?

 

Sports cat should pass an Mot, Each to their own however I've not heard many good things about revo remaps for these engines.

 

 

 

 

 

Cheers Mick, Maybe not 20 - 45 seconds, but I had been driving for an hour right before the test, so the car was fairly warm. 

 

It wasn't mapped for last tears test. I actually have a REVO SPS and set that to stock for the second test. 

 

I am confused that the car runs pretty clean at fast idle. It is just idle that the problem is, makes me think it is the injectors. 

14 minutes ago, Coopercupra said:

 

Cheers Mick, Maybe not 20 - 45 seconds, but I had been driving for an hour right before the test, so the car was fairly warm. 

 

It wasn't mapped for last tears test. I actually have a REVO SPS and set that to stock for the second test. 

 

I am confused that the car runs pretty clean at fast idle. It is just idle that the problem is, makes me think it is the injectors. 

 

You got ay ODB devices you could connect up that would give you live data?No smell of It running lean?High pressure fuel pump, injectors would usually cause the car to kangaroo at points rather than over fuel.

 

Out of curiosity what sports cat is it you have?

1 hour ago, Mickmartin said:

 

You got ay ODB devices you could connect up that would give you live data?No smell of It running lean?High pressure fuel pump, injectors would usually cause the car to kangaroo at points rather than over fuel.

 

Out of curiosity what sports cat is it you have?

Its running rich not lean. 

I am thinking the injectors could be sticking open, hence teh overfilling just at idle. I know the injectors on this engine are prone to problems.  

 

I connected a blue tooth OBD module last night, no codes, and the live data was limited. One weird thing was  I could see the live data for the 2nd O2 sensor but not the first. I will explore that further. 

I will try with my obdeleven also but I dont have an android phone any more

 

 

I have a Scorpion Sports Cat fitted. 

 

Cheers 

 

 

No Fault codes, However the voltage of the 02 Sensor is stuck at 0.47V and I guess it should fluctuate between 0.1 - 0.9 V.

1 hour ago, Coopercupra said:

No Fault codes, However the voltage of the 02 Sensor is stuck at 0.47V and I guess it should fluctuate between 0.1 - 0.9 V.

 

 

Moving forward, I am relying in a ELM OBD plug and the Car Scanner App for the moment.

 

The app does have an "emissions" diagnose function, normally I would not bother and would rely on codes and live data. But I gave it a try 

 

 

So these issues match my live data diagnosis of the O2 sensor being stuck at 0.46 V, The air to Fuel creation is 14.65, so that matches that kind of O2 voltage. Digging a bit deeper online, apart from being faulty O2 or a broken ground on the O2 sensor. It could also be a faulty EGR valve. which would match the "emissions test" on the car scanner app.  

 

I am not sure where to find the EGR valve, is it the same as the diverter valve? if it is, I should add i fitted a forge diverter valve, so could be that. 

 

Edited 9 May, 20206 yr by Coopercupra

When I got my CAVE mapped he said the twin chargers all run lean, told me to ditch tesco momentum,  for shell 99 nitro, gave a better map as well, maybe it could make a difference which fuel you use? Worth a try when you next need a full tank, take it for a blast as well before a trip to the MOT station

Edited 9 May, 20206 yr by Kobayashi
Edit

IME they run rich before running lean when hot, so hence the health black soot build up at the tail pipe which gets blasted out when the twincharger is booted.

 

There is the same additive package in Tesco Momentum as Shell V-Power Nitro +,  the only difference was Greeneergy listed the formulation and Royal Dutch Shell never.

As it is the Super Unleaded detergents and Long Life Oil detergents are can be a Twincharger killer when there is borewash.

 

I would be removing the Forge Diverter valve and seeing what is what.

But then i would get shot of a REVO remap, as i did try one for a while and it was crap. 

Thread update: Replaced the after CAT O2 sensor tonight. Now I can see the O2 voltage fluctuate between 0.1v and 0.8v, so I guess the old sensor was faulty. I guess 0.46v is default value when the sensor is faulty.

 

Onto the next issue though... Th engine seems to run on a couple of seconds after the ignition is turned off.  

So all fixed, sailed through the MOT after the after CAT O2 sensor was changed, 

 

Embarrassed to say the car wasn't running on, it was the fan rubbing on the cold air inlet pipe. 

2 hours ago, Coopercupra said:

So all fixed, sailed through the MOT after the after CAT O2 sensor was changed, 

 

Embarrassed to say the car wasn't running on, it was the fan rubbing on the cold air inlet pipe. 

Good to hear it’s sorted buddy.