Power loss & sounds like a WRX

[hks_kansei]

So if I unplug the sensor, then it will always run in open loop and use only the fixed tables? Can I surmise from this that if the phenomena goes away then it is the sensor?

Generally yes, but it's not 100% since sometimes other issues can be intermittent.

Re the leads, another easy way to test for cracked insulation etc is to just touch the leads with the car running.
If its arcing out, you'll feel it.....

My god you'll feel it..
Ask how I know...

[Purecaboos]

So if I unplug the sensor, then it will always run in open loop and use only the fixed tables? Can I surmise from this that if the phenomena goes away then it is the sensor?

Generally yes, but it's not 100% since sometimes other issues can be intermittent.

Re the leads, another easy way to test for cracked insulation etc is to just touch the leads with the car running.
If its arcing out, you'll feel it.....

My god you'll feel it..
Ask how I know...

I know that feeling well, when I used to play/learn on the good old holden red six I zapped my self many a time learning how the timing gun worked, setting the dwell by ear and so on....good times....have to relearn now that everything is electronic...

[Purecaboos]

Finally got a test drive in yesterday, actually I had to go somewhere so I took the risk and went in the MX5.

Before i left I unplugged the oxygen sensor, and surprise surprise it ran fine for the 35 minute trip out, and again on the trip back 1.5 hours later.

I guess it is the oxygen sensor and will just go and order one from MX5mania this afternoon.

Out of curiosity, the COPS system they have new says I need to mod some tacho connector???? Anyone know how easy this is to do?

Thanks for you help, I am just learning these fancy computer cars :-)

Cheers

Greg

[93_Clubman]

COPS system they have new says I need to mod some tacho connector???? Anyone know how easy this is to do? ...just learning these fancy computer cars

Great news if replacing O2 sensor sorts it completely.
Ref CoP & tacho connection, bartmanftw's Toyota Coil on Plug Guide mentions 'tach' 14 times: viewtopic.php?f=77&t=67222
However, note that bartmanftw is running a Mega Squirt ECU as opposed to factory ECU.
Btw, no points or carbies (especially two twin Webers) to dick around with on these cars!

[Purecaboos]

The new owner sensor is in, and I ordered and installed a snazzy Black stainless grill too keep the stones and birds out of my radiator.

All I need now is some testing time to go for a nice drive, otherwise I am heading to Nowra on Wednesday via Kangaroo Valley..

[Purecaboos]

After a short test today it appears that the miss fire has gone, I will do a better test tomorrow when I head down to Nowra via Kangaroo Valley and back later in the day. Perhaps I will came back via Kiama/Jambaroo road instead?

Anyway, thanks to everyone that helped out.

Failed rego check this morning as my rear tyres a below minimum tread limit on the outside edge of the drivers side tyre...and the upside is I just ordered Toyo Proxes R1R for it. As soon as they come in, new alignment and off to play again...

Cheers

Greg

[93_Clubman]

appears that the miss fire has gone

Promising!

[Purecaboos]

In Nowra, car ran like a champ all the way down....

...lets see how it goes heading back up the hill tonight.

Otherwise, Saturday for Mazda in the Mist..

Thanks everyone for your help.

Cheers

Greg

[Purecaboos]

Dammit, the miss is back this morning.

Started and ran like sh*t, had to go to the mechanic to get new tyres fitted (long story there) and it miss fired for the first 5 minutes of driving. Then it cleared itself up and drove fine for the rest of the trip there and back...

Frustrated...

might just smash in an Adaptronic and a Wideband so I have some diagnostic capability...at least that is what I will tell myself...

[93_Clubman]

Started and ran like sh*t, miss fired for the first 5 minutes of driving. Then it cleared itself up and drove fine for the rest of the trip there and back...

Was the issue previously occurring during hot & cold running?
NA6 cold idle & running issue is often due to unserviceable ECU CTS (green plastic top in pic below) at rear of head:

[bruce]

Did you change the spark plug leads?

[Purecaboos]

Started and ran like sh*t, miss fired for the first 5 minutes of driving. Then it cleared itself up and drove fine for the rest of the trip there and back...

Was the issue previously occurring during hot & cold running?
NA6 cold idle & running issue is often due to unserviceable ECU CTS (green plastic top in pic below) at rear of head:

The previous issue occured when it was warm, after a good 45 minutes of good, hard road driving.

This issue this morning was dead cold, it ran OK when we put away yesterday after a good 30 minute drive home...

[Purecaboos]

Did you change the spark plug leads?

Not yet, i did repalce the o2 sensor which fixed it for a week. It has done 500km since the sensor when in and has been fine until this morning.

I disconnected the old sensor to force closed loop mode and it ran fine for the few days while waiting for the sensor to arrive...

Still may do the plugs and leads....

[Mr Morlock]

cannot same I am surprised- it's any number of things- throw the dart- look at all the foregoing posts- and none of us know for your car.

[hks_kansei]

might just smash in an Adaptronic and a Wideband so I have some diagnostic capability...at least that is what I will tell myself...

Just so you're aware, by doing that you'll be making a heap more work for yourself since you'll need to tune it.

And to tune it you'll need to fix the misfire first anyway.

Adaptronics base tune isn't great, its enough to run ok, but the colt start and transient throttle are way, way off.

As in, their cranking fuel settings pretty much need to be ditched and start from scratch.