What Dictates A/F Ratio?

BMCC · Post by **BMCC** » Fri Aug 09, 2013 4:02 pm

Probably not a fubar'd ECT but one that has got slow and possibly a bit inaccurate over time. I believe the ECU is using voltage as reference but if you look at the charts for ECTs these are measuring in the 20k to .1k ohms resistance over time and converting into 0-5V. Don't know what a table of these ECU reference values looks like but at these resistances I wouldn't think that it would take much to make the ECU look to the wrong part of the reference table and give an inaccurate reading for injector duration.

Post by **Merlin** » Fri Aug 09, 2013 4:19 pm

Yeah I still think the ETC is one one to pursue (plus it is easy to change)

I can't find anything on when the cold start enrichment stops. But I did read this:

Service manual Page 11-53 wrote:
ECM Fail Safe
When an abnormality occurs in a signal from a sensor, the ECM ignores that signal and assumes a pre-programmed value for that sensor that allows the engine to continue to run.

IF the ETC is fooked the ECU, for the purpose of VTEC, could be ignoring it and just go on oil pressure alone? For the purpose of cold start enrichment it would make sense that the ECU make sure there is enough fuel so that the engine is allowed to continue to run. Too much fuel being better than too little?

Mind you if the sensor is not throwing a code would the ECU ignore it? Anyway I'll swap it over with the Intake Air Temperature sensor and see what happens

BMCC · Post by **BMCC** » Fri Aug 09, 2013 4:53 pm

Merlin wrote:Anyway I'll swap it over with the Intake Air Temperature sensor and see what happens

If heard of people doing this on other types of cars and its never worked out. Don't think the ECT sensor are that expensive 14-20 quid going by what my Pulsar sensor cost. Do it right and rule it out!

Post by **Merlin** » Fri Aug 09, 2013 4:57 pm

What I mean is swap both sensors on the engine with the issue with known good sensors from my spare engine. Did you think I meant swap the ECT with the IAT?

I mean to say along with the IAT

BMCC · Post by **BMCC** » Sun Aug 11, 2013 7:05 pm

Merlin wrote:I mean to say along with the IAT

That makes sense!

Post by **Donald** » Sun Aug 11, 2013 7:30 pm

All I know is that in English it's around 3.6:1

No idea what you lot are on about.

Post by **Merlin** » Mon Aug 12, 2013 9:04 am

It seems to be sorted now. The ECT sensor was full of oil. We cleaned the sensor and plug, let it dry, reset the ECU and the car doesn't seem to spew out the same horrendous stink of fuel.

BMCC · Post by **BMCC** » Mon Aug 12, 2013 10:12 am

Full of oil? Any reasons for this? Oil in the coolant........

Post by **Merlin** » Mon Aug 12, 2013 10:22 am

No nothing like that. Oil in the actual plug where it joins with the connector. It must have not been getting an electrical connection. The oil leak is from the rocker cover / cam end seal / VTEC solenoid area.

BMCC · Post by **BMCC** » Mon Aug 12, 2013 10:26 am

So the oil leaks next on the list if its not be done already?