Poorly emission on my F355

[MalcH]

My F355 (5.2) Berlinetta is currently without an MOT and with a specialist.
The car failed the MOT two years ago on emissions. That turned out to be something in the wiring loom, though I know not what exactly.
Failed again this year. CO is in the region of 6 and I believe as high as 10 but due to that clogging the filters on the emission testing equipment the MOT tester could not print the reading. That's at least 12x more than it should be :shocked:

It failed at all levels, idle and 2500-3000rpm. Not sure what the Hydrocarbons were but I think they too were high.
It's been on Ferrari SD1 and on the day it reported an open loop' on all four oxygen sensors. Since then a sensor was changed and made no difference (as kind of expected, from me anyway). The last time it was, I was lead to believe an earth (wiring loom earth?) but am told not so this time.
So it seems the sensors are probably OK. They now said at idle the oxygen sensors are in 'closed loop' but when the engine is revved they go to 'open loop'.

Anyone any ideas that I can pass on? The specialist is pretty busy and not really had much time to spend on it, so I'm asking on the off chance

 

[J70]

Can't help I'm afraid, but I hope someone can because its something I'd like to know more about too.

 

[Nosevi]

Hi Malc. This is the readout from my MOT. It's not posted to take the mickey, more to make a point.



The Motronic is a pretty nifty bit of kit. It should test the injection and emmission system and make corrections to the system based on what it finds. Yours is obviously either a 2.7 or 5.2 but I think both work in more or less the same way. If you don't drive your car often (and I know you haven't) 2 things can happen. firstly the system isn't as 'clean' as it could be having sat for months on end and secondly the battery can go flat. If the battery goes flat the motronic defaults to factory default when you fire it back up, and expects the system to run as it did the day it left Maranello. The problem is very few cars will run exactly the same and so the injection system won't run optimally.

My car for example has high flow air filters, high flow race cats and bugger all in the exhaust to create any resistance. When I fire her up the motronic isn't expecting that and so it basically gets its numbers wrong. The good news is an ECU reset can tell the motronic how it should be running and it can compensate for many changes to the way the engine should be running compared to how it is.

The second side of the equasion is what was refered to me as an 'Italian Tune up'. My car was running a little rough after sitting idle for a while and it was suggested to me by an Italain friend that I give her an Italian tune up. I asked what one was and was told it's quite simple - get her fully warned through then totally thrash the engine. Once you've done this, leave her over night to get totally cold then do a full ECU reset so the motronic can 'learn' the new settings. I do this before every MOT and always pass with emmissions as you see them - close to clean air.

It's worth a shot as it's a free option. An ECU reset is merely to take the car from totally cold, and fire her on the key without touching anything electrical or having ac on etc. Leave the car idling without touching the accelerator until the fans kick in, some people let the fans cool the car a bit and switch off then kick in a second time. Once this is done the Motronic should be set to the new numbers and you can drive as normal.

Like I said, worth a shot

 

[Garvin]

+1 for the 'Italian tune up' - I've been using this method since I've owned cars and it does work. Years ago Mrs Garvin was convinced I had done something clever with her cars as she always remarked that they went so much better after I had taken them out to check they were running OK. When I eventually demonstrated the ITU method she was a little unnerved by it but admitted it worked well! But I digress somewhat . . . .

It's a bit difficult to undertake an ITU legally without an MoT (or your own closed track) but it might be worth disconnecting the battery for a while, reconnecting and the going through the procedure for the ECU to relearn the main settings. This might do enough to get it through the MoT.

Afterwards though, warm it up thoroughly and then go drive it like you stole it - revs between 5k and the red line for a good half hour or so. Then go through the whole reset procedure from cold again. Then do it at least twice a year - it's a very enjoyable and cheap way of servicing the car :grin:

 

[Mike01606]

Afterwards though, warm it up thoroughly and then go drive it like you stole it - revs between 5k and the red line for a good half hour or so. Then go through the whole reset procedure from cold again. Then do it at least twice a year - it's a very enjoyable and cheap way of servicing the car :grin:

Doesn't this just wipe the adaptive settings again?

Malc,

I'd consider taking it to a different specialist. Not necessarily a Ferrari one but possibly a decent Motronic specialist. I'm not sure about the pre 2000 cars and OBD I or II but for this kind of issue I'm not sure you'd need an SD.

The car should run open loop from cold until certain parameters are met then switch into closed loop and stay there. Anyone who understands the operation will be able to work out what's happening rather than just swap parts.

 

[Garvin]

Doesn't this just wipe the adaptive settings again?

Yes, but if you don't drive it very often then those adaptive settings start to accommodate the cumulative effect of relatively short, slow journeys. The ITU blows the crap out of the system ensuring cats etc burn off any accumulated crud, allows good quality fuel to really get its cleaning power to work on those valves etc.

The adaptive settings take some time to adjust, the reset procedure 'kick starts' the process somewhat and, after a good clean out should give reasonable settings in a short period of time.

Of course, if you drive the Ferrari as it it meant to be driven and regularly then everything stays in much finer fettle and the reset procedure is not really necessary.

 

[NWRed360]

The car should run open loop from cold until certain parameters are met then switch into closed loop and stay there. Anyone who understands the operation will be able to work out what's happening rather than just swap parts.

This is important... Open loop operation is normal during the engine warm up phase, the ECU can't achieve Lambda =1 with enriched startup mixture. So, it is essential to have the engine up to full operating temperatures before the emissions test and clear of any enriched fuelling before the test is started. I have a friend who is an MoT tester (at a Jaguar main dealer) and he says they get a number of cars for retest which have failed MoTs at "other franchises" because the testers don't allow the car to get fully up to temperature. When tested "properly" the cars are fine. Basically, time is money and a large engine takes time to fully warm up. This should be something either the specialist or MoT tester should be fully aware of, but is always worth asking.

The ITU blows the crap out of the system ensuring cats etc burn off any accumulated crud, allows good quality fuel to really get its cleaning power to work on those valves etc.

Whilst I'm sure the ITU has some merit, my car hasn't needed this to pass its MoT in the past two years. I'm a limited mileage user (<2k p.a.) with ~4-6 months of no running over the winter, I definitely haven't driven it like I stole it, and my MoT readings are very similar to those posted by Nosevi above.

So, if the car is running open loop at full operating temperature, then there is something wrong, IMO.

 

[Rustybits]

Check the lamda (front and rear) have been connected the right way around. Had this issue a few times where people connect them the wrong way around after engine out service and they stay in open loop...

 

[MalcH]

Hi Malc. This is the readout from my MOT. It's not posted to take the mickey, more to make a point.

View attachment 141917

The Motronic is a pretty nifty bit of kit. It should test the injection and emmission system and make corrections to the system based on what it finds. Yours is obviously either a 2.7 or 5.2 but I think both work in more or less the same way. If you don't drive your car often (and I know you haven't) 2 things can happen. firstly the system isn't as 'clean' as it could be having sat for months on end and secondly the battery can go flat. If the battery goes flat the motronic defaults to factory default when you fire it back up, and expects the system to run as it did the day it left Maranello. The problem is very few cars will run exactly the same and so the injection system won't run optimally.

My car for example has high flow air filters, high flow race cats and bugger all in the exhaust to create any resistance. When I fire her up the motronic isn't expecting that and so it basically gets its numbers wrong. The good news is an ECU reset can tell the motronic how it should be running and it can compensate for many changes to the way the engine should be running compared to how it is.

The second side of the equasion is what was refered to me as an 'Italian Tune up'. My car was running a little rough after sitting idle for a while and it was suggested to me by an Italain friend that I give her an Italian tune up. I asked what one was and was told it's quite simple - get her fully warned through then totally thrash the engine. Once you've done this, leave her over night to get totally cold then do a full ECU reset so the motronic can 'learn' the new settings. I do this before every MOT and always pass with emmissions as you see them - close to clean air.

It's worth a shot as it's a free option. An ECU reset is merely to take the car from totally cold, and fire her on the key without touching anything electrical or having ac on etc. Leave the car idling without touching the accelerator until the fans kick in, some people let the fans cool the car a bit and switch off then kick in a second time. Once this is done the Motronic should be set to the new numbers and you can drive as normal.

Like I said, worth a shot

Definitely something in that. Apart from a trip to the specialist for a service and back and then to the MOT test station (all in about two weeks) that is all it's done since last year.

Doesn't this just wipe the adaptive settings again?

Malc,

I'd consider taking it to a different specialist. Not necessarily a Ferrari one but possibly a decent Motronic specialist. I'm not sure about the pre 2000 cars and OBD I or II but for this kind of issue I'm not sure you'd need an SD.

The car should run open loop from cold until certain parameters are met then switch into closed loop and stay there. Anyone who understands the operation will be able to work out what's happening rather than just swap parts.

Spoke to them today, in fairness they're so busy it just sat in the workshop until yesterday. Other than from when I took it straight from the MOT station to them they had not touched it.

Yes, but if you don't drive it very often then those adaptive settings start to accommodate the cumulative effect of relatively short, slow journeys. The ITU blows the crap out of the system ensuring cats etc burn off any accumulated crud, allows good quality fuel to really get its cleaning power to work on those valves etc.

The adaptive settings take some time to adjust, the reset procedure 'kick starts' the process somewhat and, after a good clean out should give reasonable settings in a short period of time.

Of course, if you drive the Ferrari as it it meant to be driven and regularly then everything stays in much finer fettle and the reset procedure is not really necessary.

I spoke to them today and that is part of what they have done. Hopefully to ease my pocket they have not spent too much time on the car.

Check the lamda (front and rear) have been connected the right way around. Had this issue a few times where people connect them the wrong way around after engine out service and they stay in open loop...

It's possible, but then they were working last MOT and I don't think they'd have been removed at service time... :hmmm:

When I spoke to them today (I do have confidence in their ability BTW) the car was running whilst I was on the phone (I heard it) and as whilst it was warming up it was still in an open loop but earlier or rather yesterday when confirmed it went to closed loop after it had warmed up.
On the day of the MOT it was warm, I took it straight from the MOT station to the specialist and it was still warm and in an open loop on the circuit from the oxy sensors.
Hopefully taking it for the MOT today or tomorrow.

 

[360trev]

Check the lamda (front and rear) have been connected the right way around. Had this issue a few times where people connect them the wrong way around after engine out service and they stay in open loop...

+1

That must be a "DOH!" moment....

Obviously just to add to this poor emissions are most often caused by overfueling or poor catalyzer efficiency

0. Battery could be poor causing havoc with electronics (such as ignition computers).
1. The Ignition coils aren't getting the battery power they need to operate correctly (think battery or wiring) after the instruction is given from the Motronic engine computers to fire. (or one has gone bad - you can test their resistance with a multimeter)
2. Spark Plugs are not efficiently converting that power from the ignition coils into a nice clean spark front (i.e. in need replacing, dirty or fouled)
3. Fuel Injectors aren't atomizing the fuel well (they could be worn or dirty and need of an ultrasonic clean)
4. Fuel Pressure isn't being regulated correctly (easy to check - could be the fuel pressure regulator) and overpressure is causing more fuel to enter than normal despite the duty cycle being the correct.
5. After burning the mixture in the cylinders (assuming engine is healthy) the gasses go out via the manifolds and passed the O2 sensors (pre and post cats). As Eddie pointed out, if they are the wrong way around it will confuse the hell out of the computer and could cause it to increase the fuel trim (!).. Silly Bosch ignition computer engineers should have been able to detect this but probably never expected this to happen in their ecu programs.
6. In between the o2 sensors is the catalyzers, if they are damaged (due to overfueling in the past - which can also take out the o2 sensors!) they may need replacing.
7. If there are any gasket or intake leaks leading to extra air (unmetered) entering either the intake or from the manifolds they can confuse the ignition computer algorithm.
8. And not forgetting if the Air Flow Meters are operating correctly and the Throttle Bodies too (and giving an accurate level of air entering the system).

Usually the ignition computers can monitor most things [generating a CEL illumination] and adapt accordingly but ofcourse the old fashioned way was to walk through systematically all of the above until you solve the issue. Good luck!

-T

 

[MalcH]

Obviously just to add to this poor emissions are most often caused by overfueling or poor catalyzer efficiency

0. Battery could be poor causing havoc with electronics (such as ignition computers).
1. The Ignition coils aren't getting the battery power they need to operate correctly (think battery or wiring) after the instruction is given from the Motronic engine computers to fire. (or one has gone bad - you can test their resistance with a multimeter)
2. Spark Plugs are not efficiently converting that power from the ignition coils into a nice clean spark front (i.e. in need replacing, dirty or fouled)
3. Fuel Injectors aren't atomizing the fuel well (they could be worn or dirty and need of an ultrasonic clean)
4. Fuel Pressure isn't being regulated correctly (easy to check - could be the fuel pressure regulator) and overpressure is causing more fuel to enter than normal despite the duty cycle being the correct.
5. After burning the mixture in the cylinders (assuming engine is healthy) the gasses go out via the manifolds and passed the O2 sensors (pre and post cats). As Eddie pointed out, if they are the wrong way around it will confuse the hell out of the computer and could cause it to increase the fuel trim (!).. Silly Bosch ignition computer engineers should have been able to detect this but probably never expected this to happen in their ecu programs.
6. In between the o2 sensors is the catalyzers, if they are damaged (due to overfueling in the past - which can also take out the o2 sensors!) they may need replacing.
7. If there are any gasket or intake leaks leading to extra air (unmetered) entering either the intake or from the manifolds they can confuse the ignition computer algorithm.
8. And not forgetting if the Air Flow Meters are operating correctly and the Throttle Bodies too (and giving an accurate level of air entering the system).

Usually the ignition computers can monitor most things [generating a CEL illumination] and adapt accordingly but ofcourse the old fashioned way was to walk through systematically all of the above until you solve the issue. Good luck!

-T

I like that you have used zero to start and not 1, done a bit of programming in your time :laugh:

0) I've certainly never changed the battery in five years. It is always on an Accumate when not in use but that don't stop them wearing out.
1) No idea.
2) I don't know without looking at history when and if changed.
3) I can ask.
4) As above.
5) I really hope this was not the case.
6) Both cats have been replaced whilst in my custody. A new lambda was tried and that had no effect. As all four were showing open the fault was more likely elsewhere.
7) Don't know.
8) as above.

Thanks though, I will make a note of these just in case. :thumbsup:

 

[360trev]

PS. Forgot to mention a little story about cats from a long time ago...

Back in 2000 when the Nissan GT-R (R34) was a few months old they where having a hell of a time individually SVA approving each one as a personal import. Those engines ran very rich (especially so when cold) as a protection and cat efficiency is rather poor (i.e. they don't work) below a certain operating temperature. So the only way that Andy Middlehurst (Nissan Garage owner who did the first early 'official' Skyline imports) could get them to pass was to drive the cars hard on the local A road and get some proper temperature into the cats! Once they where fully warmed up after some spirited driving (!) they where taken immediately into the MOT testing bay and the emissions where checked!!

It may be that your race cats are very high flow and giving the car a hard run could indeed make them work to convert the gasses more efficiently.

 

[MalcH]

PS. Forgot to mention a little story about cats from a long time ago...

Back in 2000 when the Nissan GT-R (R34) was a few months old they where having a hell of a time individually SVA approving each one as a personal import. Those engines ran very rich (especially so when cold) as a protection and cat efficiency is rather poor (i.e. they don't work) below a certain operating temperature. So the only way that Andy Middlehurst (Nissan Garage owner who did the first early 'official' Skyline imports) could get them to pass was to drive the cars hard on the local A road and get some proper temperature into the cats! Once they where fully warmed up after some spirited driving (!) they where taken immediately into the MOT testing bay and the emissions where checked!!

It may be that your race cats are very high flow and giving the car a hard run could indeed make them work to convert the gasses more efficiently.

One is OEM and one is not. IIRC.

 

[360trev]

I like that you have used zero to start and not 1, done a bit of programming in your time :laugh:

0) I've certainly never changed the battery in five years. It is always on an Accumate when not in use but that don't stop them wearing out.
1) No idea.
2) I don't know without looking at history when and if changed.
3) I can ask.
4) As above.
5) I really hope this was not the case.
6) Both cats have been replaced whilst in my custody. A new lambda was tried and that had no effect. As all four were showing open the fault was more likely elsewhere.
7) Don't know.
8) as above.

Thanks though, I will make a note of these just in case. :thumbsup:

Yes, fair bit of development over the years

The easiest one to check (and very often overlooked) are the o2 sensors and the spark efficiency (take the plugs out and inspect them). Spark plug condition can tell you amazing amount about how the combustion is doing...

Good luck!

 

[360trev]

One is OEM and one is not. IIRC.

:hmmm: I wonder if that would cause confusion to the computers? @ Eddie, any views?

 

[Garvin]

. . . . . Apart from a trip to the specialist for a service and back and then to the MOT test station (all in about two weeks) that is all it's done since last year. . . . . .

Your car is pining for a good thrashing - I would wager a (very) small fortune that this is the root of the problem. Get it out on the open road and give it 'the beans' . . . . . you know it makes sense :grin:

If the O2 sensors were staying open loop then it may point to a dodgy engine temperature sensor.

Short journeys whilst in open loop will not do the cats any good at all, they need heat and plenty of it without over fuelling to operate correctly.

I suggest you make time for a good half hour run with plenty of WOT before the MoT :drive:

 

[ric355]

Those people recommending a reset of the ECU might not be aware that in the workshop manual for the 355 there is a paragraph which states that the M5.2 ECU cannot have the adaptive parameters reset by disconnecting the battery. It has to be done on an SD1 using the reset adaptations command. They refer to it as "does not allow the parameters to be cancelled or reset by cutting the ECU off" but I'm sure they mean by disconnecting the battery. Other parts of the manual contradict that but I'm inclined to believe it because they'll have originally written it for 2.7 cars then added bits for the 5.2 cars later.

There is also a list of the conditions required for open loop operation in the workshop manual. These are "or" rather than "and":

• Oxygen sensor not sufficiently heated (below 572F)
• Engine coolant below 60C and above 15C
• Accelerator fully depressed (>72 [probably means percent] throttle angle)
• Engine RPM > 4000

So there are your clues for things to check if it won't go into closed loop. The first two are conditions for the air injection pump to run as well, but I wouldn't rule them out as OK just because the air injection pump (the whistle at start-up) switches off - they could be intermittent.

A test of the throttle pot is easy with OBD or SD1 readers
Incorrect RPM reading seems unlikely - is your tacho working?

The first bullet is worth considering: O2 sensors have inbuilt heaters so they work quicker. If the heater fails the sensor will eventually get hot and it'll start working, but prior to that point they won't give a proper signal. It's often the heater that fails rather than the sensor itself. This condition can make them seem OK sometimes.

 

[MalcH]

Ric that is great info, thanks.

I know the RPM counter is working. Another O2 sensor was tried and it went to open loop.
The car I've left with the specialist and am just awaiting a phone call.

Garvin, I'd love to roast the car's nuts, unfortunately it needs an MOT

 

[Mike01606]

Garvin, I'd love to roast the car's nuts, unfortunately it needs an MOT

Malc,

Can't you take it for a 'pre-booked' one? [emoji10]

 

[Garvin]

Garvin, I'd love to roast the car's nuts, unfortunately it needs an MOT

When you get it sorted, which you will, then make sure you do . . . . . . and regularly :grin: