R500K m.o.t. Emissions problem - HC ten times too high (running very rich)

[anthonym]

Ok, Swiss mot, but makes no difference as it's miles out.

Recent new engine loom, loom wired for Emerald K6 ("on the fly", but double checked). She runs very well apparently. 

Also replaced plugs, leads, dizzy cap. Also reset the TPS physically and then in software.

Also replaced cam belt and water pump, and tensioner.

Balanced throttle bodies airflow

I am 1,000 miles from the car so this is a guessing game so I have things to check when finally I get there; I will connect laptop to the Emerald K6 and the Emerald software.

Apparently it is SO far out it should/will be obvious.

Oil temp 76.

The fuel was 7 months old, I added a load of octane booster, then emptied all fuel but 5 lites and filled with fresh 98.

Powerspeed exhaust with Cat.

At the time of these tests she had done only 20 miles since all the above.

What do you think it is?

Anthony

(1) Disconnected temp sensor? (which?)

(2) ?

 

[anthonym]

https://www.lotus7.club/comment/1588741#comment-1588741

about TPS

https://www.lotus7.club/comment/2148712#comment-2148712

[revilla]

Interesting read but ... the question is, what has changed? It has passed before.

[7 wonders of the world]

If your on the emerald hook up the laptop save the map and retweak it, if you cock it up you have the old map to go back to, once sorted you can load this as one of the 3 maps - assuming you have the dash switch ?

 

[anthonym]

I suspect the bits I did myself, especially TPS

yes I have the. Dash switch, now connected for the first time

[revilla]

Do check all the sensor values on the laptop. Especially temperatures and TPS. As we did convert an MBE loom to Emerald on the fly, there's always the possibility that something is misconnected. Look for gross errors, for example I know that on MEMS3 if there's a wiring fault to the IAT it reads as -40°C. Look for anything that really doesn't make sense rather than fine details.

[anthonym]

Presumably the approximate proper readings will be in the book or even shown o n screen like blood test results...

[revilla]

No, approximate readings are just common sense. If it's a spring day in Switzerland and the air temperature says 10°C or 15°C it makes sense. Water temp will start off similar and should agree roughly with your temperature gauge as the engine warms up. If it says 150°C when the engine is cold, or doesn't rise as the engine heats up, it's wrong. For the TPS I think you already know the voltage it is supposed to be calibrated to when the throttle is closed. As you open the throttle it should rise steadily, probably to somewhere close to 5V. It's actually unlikely to be the TPS if its idling OK as the throttle won't be open far holding a steady 3000rpm unloaded, it certainly won't be the top end of the TPS scale so as long as it starts at whatever it's supposed to be and rises smoothly with the first bit of the throttle it will be OK.

[anthonym]

I am noticing a common “thread” in threads like this is the temp sensors being suspect. That I-can think of are oil water and air. Earth Wind and Fire don’t seem to have sensors. 

[revilla]

Water temp would be a prime suspect. If the ECU thinks the engine is cold when it is hot, it will overfuel.

[anthonym]

So compare Stack dash water temp to Emerald K6. Figure.. samefor oil. Presumbly.. and to common sense

[revilla]

Don't think you have an oil temperature sender for the ECU. Only VVCs had that, so they could estimate the oil viscosity and therefore the response speed of the VVC hydraulics. If you have an oil temperature sensor it will just be for the temperature gauge (and therefore not relevant here). Just water and inlet air temperatures.

[anthonym]

and come to think of it there are two separate coolant senders side by side in the hose.. one could be working and the other not. And. Until today the engine has not been warmed up, aside from at tickover..  plugs before being changed, last job done:

 

[revilla]

Only one of those coolant sensors is relevant. One is for the ECU, one is just for the temperature gauge on the dash and completely unconnected to the running of the engine. Typically the gauge one has a single spade terminal (but I have seen variations). Typically on an EU2 engine the ECU coolant temperature sensor will be a 19mm hex brown plastic body with a two terminal plug.

[anthonym]

Sounds familiar. So I will be thinking the temp works fine because the irrelevant temp sensorworks fine.

 

[revilla]

Yes what you are seeing on the gauge and what the ECU is seeing can be different as they use different sensors.

[anthonym]

Time for an OBD reader and app?

[revilla]

May be wrong but I don't think your Emerald supports OBDII ... Just use the Emerald software on your laptop.

[Mike Biddle]

One of the plugs in the photos looks like it's running rich. Could be an injector problem?

[rj]

Second that.

Plus, if the fuel is old...

https://www.bp.com/content/dam/bp-country/en_au/media/fuel-news/petrol-life-vehicle-tanks.pdf

 

HOW PETROL CHANGES IN EQUIPMENT TANKS Loss of light components – impact on mixture The light components in petrol are lost first as the petrol sits in the fuel tanks. These components provide valuable octane benefits during cold start. Because they are volatile they compose most of the air fuel mixture during cold start, if they are absent then the mixture becomes lean resulting in higher temperatures, pre ignition, detonation and piston damage. This is generally the cause of piston damage in high revving engines used in boats and small engines such as chain saws etc. The portion of the petrol that remains has a higher density and higher octane but this is not available during cold start resulting in hard starting. Because the fuel carburetors and injectors operate on a volume metering system the higher density means that more fuel is introduced for a given volume of air and so the air fuel ratio is fuel rich. If all the fuel cannot be burnt then it forms carbon deposits that will foul the spark plug and cause the engine to stop and not start. This is generally the cause of problems in classic cars where the engine stumbles and hesitates or cuts out.

[CageyH]

Is the lambda sensor ok?

 

I assume that you have the normal narrow band sensor installed, and have not gone for a wide band lambda sensor?

[oilyhands]

You will be able to tell from the live adjustments screen if the Emerald is making temperature related adjustments to the fuelling, that will give you a clue, if you have fitted a new TPS then it will not be correctly aligned to the map so you will need to do a TPS align procedure which is straightforward in the Emerald software, also check your TB balance. If the fuelling adjustments are high after the TPS re-align when the engine is hot and the temperature reading low then you can then suspect the coolant temperature sensor, if the temp reading is OK and the TPS aligned, then you can back off the fuelling at the appropriate load/speed site, if you disable idle control then the engine will pretty soon tell you when the fuel is too lean/too rich by its behaviour.

Oily

[Ivaan]

Have you checked the cam timing? Makes a big difference to emissions. 

[anthonym]

Just replaced the cam belt, is that a risk of changing the cam timing?

[revilla]

Just slackening the lower pulley bolt can allow the timing to move by a few degrees as there is some slack in the fitting of the lower cam belt pulley to the crank. On one I measured it as a total of about 6 crank degrees of "slop". On an average engine with stock timing it doesn't make so much difference but on an R500 tuned to the eyeballs it may well be enough to upset it. Just making sure you get the new belt on the right tooth may not be accurate enough. I think I mentioned that ideally you would re-time the cams after changing the belt at the time you were doing it. If nothing else shows up as being wrong I would get the cam timing checked out properly, e.g. Lift at TDC with dial gauges as per Dave Andrews' website.