Question regarding 02 Sensor,
Today was a interesting day. I took off my original 02 Sensor and guess what I found out...it was dead, burnt, busted!
Now here's the question...could this have contributed to these problems...
Converters prematurely dying?
Car running rich?
Oil consumption?

1988 none turbo RX7

 

Yes, it could have contributed to at least the 1st 2, if not all.

The 02 sensor provides the ECU with Air:Fuel ratios, which adjusts the mixture to whatever it is supposed to be. If the oxygen sensor is broken, the ECu has no idea what the mixture is, and will pump that extra fuel which is why you are running rich. When you run rich, it wears out the cat alot quicker cause theres a lot more stuff to filter in the exhaust.

 

The lack of, or In your case, non functional O2 Sensor would cause your Cats to burn out and your Fuel Economy to plummet.

 

Of course, this only applies to highway driving. The O2 sensor is barely used in the city...

 

I put in a new bosch O2 sensor last week and it seems to kick it into closed loop in the city, any time it's maintaining a decent speed or mild acceleration. eg. crusing at even 30kph. With just a dab of throttle or none it's open loop. A fuel injection book from C. Probst indicates it should be in closed loop at idle (mine isn't). So other than high throttle or throttle lift, when *should* it be in closed loop?

 

thx =)
i HOPE TO HAVE MY CAR UP AND RUNNING SOON. I've decided to wait until I install the new cat's before I replace the O2 Sensor. I think that makes sense!

 

dude..I don't understand the question!!!!!

 

Under cruise, it should be closed loop. What I meant is that the O2 sensor is hardly used in the city because you're so often in open loop. Though I guess it matters where you are...

 

Are you in open loop because you're gunning it all the time or it fits into one of the scenerios I was asking about?

 

The ECU will go closed loop under light throttle when the engine is warm. It will go open loop if:

1. the engine is cold
2. your giving it some throttle
3. your above 3800 or so rpm's (regardless of throttle)
4. Idle. At idle the A/F is trimmed by the var resisitor on the passenger side shock tower.
5. Your O2 sensor is bad

Decel gives fuel cut which I guess you could say is open loop or 'no loop'...

Henrik
87TII

 

The RX-7 doesn't go into closed loop at idle. It runs open using the setting on the idle mixture screw.

 

Where is the idle mixture located????

 

Passenger shock tower...Have you still not bought a repair manual?

 

yeah I have one, but I didn't see anything about "idel mixture!!"..is that the correct name?