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Old May 19, 2002 | 09:05 PM
  #1  
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JIM THEO
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Could someone tell me when the O2 sensor is very hot how much under reads?
When I take measurement (Delta Dash) with third gear I always have leanest mixture than with 4th or 5th.
Car idle for 3-4 minutes until the rpms drop to 750-800, I drive it slowly 2-3 km and then I take the measurements first with third and then with 4th and 5th gear. I found out also highest coolant temperatures on the first run with third! What is wrong and what you guys have seen on your cars?
JIM
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Old May 20, 2002 | 12:22 PM
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What were your readings in third?

The coolant temps will be warmer when the car has been idling and then driven slowly before you give it stick. Once you give it and it receives cool air the temperature will drop eventually. In 4th and 5th the car is travelling faster so, it gets more air and the temp drop more than it would in third.

Cheers,

Wrexy.
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Old May 20, 2002 | 04:50 PM
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Hi George
I compared my old log files before the PE manifold with the new, and I found out a big difference between various measurements.
With third gear I have sometimes very lean mixture (<0,87V), however other log files with 3rd show me very rich mixture!!! With 4th or 5th I always have the same results. I guess because the first run is after stop-go on the traffic lights my EGT is higher and so the O2 reading is fault, or am I wrong?
I'll send you my new log files to have a look.
JIM
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Old May 20, 2002 | 04:57 PM
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Try cruising at 50ish for a minute or too to get it at the right temp and then boot it.

Matt
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Old May 20, 2002 | 09:53 PM
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Thanks George, Matt
I'll try to drive the car at 50 before I'll take some measurements.
JIM

[Edited by JIM THEO - 5/20/2002 10:19:27 PM]
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Old May 20, 2002 | 10:38 PM
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My data log runs have been done in third only, also. And my readings were 0.865 /0.87 volts also. I too let it idle on cold startup, then cruise slowly, around 60kph which is around 37mph, to the road I normally do my test on which is around 3 miles away. I have to travel for around 45 minutes if I am to get to a road where I can stretch out 4th and 5th gear. I'ts too far and by the time I would get there, I assume the lambda sensor would be hot, hence why I go to the road where I stretch out 3rd gear.

Could this be why I get 0.87 volts too?

Cheers,

Wrexy.
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Old May 20, 2002 | 11:17 PM
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Goodness chaps, I've taken an absolute mountain of fuel out of mine and just got it to holding 0.89 through the midrange and going over 0.90 after 6000 RPM. What on earth is going on in Greece?
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Old May 21, 2002 | 12:27 AM
  #8  
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The thing is, am I doing the test right? Does the above start up from cold, then driving procedure I'm doing before the test sound ok? Our Ambient temps are 25 to 28 deg celsius.

My laptop has gone in for some warranty work and I'm waiting for it to come back, so I can test another AE 802 ECU to see if my AE 802 is faulty. I also want to unplug my lambda sensor, to see if delta dash displays 0.3 volts to see if it is faulty.

Cheers,

Wrexy.
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