Problems with emmisions, still..

[Simon]

Still can't ge the touring through the MOT.

Car is reading between 8-9% on the CO.

Fitted a brand new blue temp sensor, tried replacement ECU and AFM, but none have made any difference.

The only time the reading comes down is after coming off the gas, but it shoots straight back up.

Any ideas?

How can I check the AFM to see if it's working as it should?

[kam-325i]

Leaky injector ????
Fuel Pressure to High ?

[E30Mark]

Accidently slip the probe up another cars rear pipe

I'm sure Ant may have some sensible suggestions.

[Jon_Bmw]

Cough/Vacuum leak/Cough.

This works very well on a turbocharged car, so the principle should work the same on a NA engine. Have you not got a cheap CO emmision tester you can fiddle about with a few settings. They are fairly reliable for around £50. Especially since you can effectively calibrate it with the readings the MOT gave you.

[tailoutcharlie]

When my mates mini wouldn't go through emmisions the friendly tester turned on all electrics he possibly could including all the ICE in the boot, it put such a drain on the engine it creeped in under the limit.

Seems odd to me but he swears it worked, could be worth a go if its almost there

[Simon]

The tester is a good friend, so getting on the machine isn't a problem, I really want to get it running properly tbh, as it's not doing any good overfuelling as it is.

I changed the oil yesterday, and it was like water there was so much fuel in it. It hasn't been back on the machine since changing the oil, could this affect the CO?

Any ideas on testing the AFM to see if it's doing it's job properly?

Adjusting the mixture screw doesn't seem to make much difference, as it re-compensates itself.

[Ant]

need to know the HC and CO please Simon

Fuel contaminated oil will brethe into the inlet so could cause excessive CO readings but yours is V high.

AFM is ignored for idle fuelling so the PCB inside can be ignored for diagnostic purposes on this occasion.

A leaking FPR could cause this , a failed diaphragm could allow fuel to be injected via the vacuum hose, not good for emissions for sure.

What have you swapped about so far to attempt a fix ??

[Simon]

Just the man..

CO on the fail sheet is showing 8.740%, and the HC is 762 ppm.

FRP is about 1 year old, and is a genuine bosch item.

3 AFM's have been tried, new blue temp sensor has been fitted, (BMW sensor). Also tried replacing the ECU.

Now also changed the oil too.

[Simon]

OK, changed the oil, it has brought the CO down to the 6-6.5 mark now.

Still not enough to get it through

[Brianmoooore]

How come there was fuel in the oil in the first place? Or is this another symptom of the rich running?
Has the C192 injector loom plug and socket been checked out?

[Simon]

Basically, the car has been stored in a covered compound for the last 4-5 months, and has been moved in and out a lot.

Obviously with the overfuelling fault, and a lot of cold starts, fuel has been finding it's way unburnt into the sump.

Brian, what exactly am I looking for?

[Brianmoooore]

Brian, what exactly am I looking for?

Rotted wires under the lower rubber boot, or corrosion on the pins/buckets.
The blue temperature sensor signal passes through this connector.

[Simon]

Thanks Brian, will take a look tomorrow.

[charlE30]

Would the spark plugs have anything to do with high emissions? I only ask as my tourer failed on emissions 4.34% and 507ppm and with new spark plugs it passed at 0.95% and 112ppm (unsure if the garage did anything themselves to get it down)

Good luck finding the issue Simon.

[Brianmoooore]

Would the spark plugs have anything to do with high emissions?

If a plug is causing a misfire, then high CO will result.

[Jon_Bmw]

But it should be fairly obvious if you have an idle misfire. It certainly is on a 4 pot that is running on 3.

[Simon]

Well, the car now has an MOT certificate.

Only problem is, after getting the car back, I'd realised I'd forgotten to refit the dipstick.

The car is still way too high on the CO.

Checked the wiring, no corrosion, or rotten wires.

Am I right in thinking that if it was a leaky injector, then only the spark plug for the port with the leaky injector would be wet? All 6 plugs are soaked..

[Brianmoooore]

An E30 in half decent condition should have no problem at all getting through an MOT at well under the limits. There's something very wrong with this car.
Leaking injector would only affect that cylinder, but a FPR with a leaking diagphram would affect them all.
Measure the resistance from pin 45 of the ECU plug to earth with the engine at full working temperature. (Take the plug off, identify the pin and mark it, put the plug back on, run the engine up to temp., take the plug off, and measure the resistance.)

[greenbimmer]

Excuse me to bother..
Mine an m40b18 engine, failed CO-adjustment, since it keep too low on 0,18% at idle RPM 800, even when i turn the CO-adjsuter on the AFM..

In higher RPM (>1500) the reading changing, and seems the gas/CO analyzer is normal since it also used on other cars..

Is there any chance that the air temperature sensor (inside the AFM glove / near the flap-door) is broken..?

Thanks.

PS: Sory for my broken english.

[Supafly]

Sorry I can't help with the m40.

are you able to check the fuel pressure? and have you taken the vacuum pipe off to see if there are traces of fuel in there? I think I remember reading about swapping a bit of clear windscreen washer hose to see if fuel was being sucked into the inlet through the fpr.

[greenbimmer]

Just give up and take my m40 to a german-car specialist workshop.
Seems it caused by 2 things:
1). the carbon track: although i've refurbished it (re-locate the wiper track), but the reading would be failed since the track in idle position were almost 'clear' (can see the board), so i got it re-carbonized
2). the Throttle Position Sensor (TPS) failed to close the gap sometimes, caused by dirt.. Cleaned also with the TB & ICV too, and now it works smooth and got a great acceleration.. but, alas, i forgot to check the CO again..!

Thanks mate!