Dwell reading and CO adjustment

[madstudios]

Hi everyone!
Today I've tried to make my first dwell reading, I've just replaced my 02 sensor with a new one (it was disconneted before that) and now I need to make mixture adjustment.
I've followed the procedures from other topics, but I'm not sure what's going on.
Here is a picture of my dwell meter.
IMG_2730.JPG
And here is the video of my today's dwell reading.

Car was warm, fans on.
But reading was about 75 on 4 cylinder scale.

But, after 10 minutes of reading, I've heard a buzzing sound, and I noticed that interfered on dwell reading, here is the video when started the buzz.

When buzzing, the read drops to 42...

My car was running ok without the 02 sensor, but smelling gas a lot.
With the sensor connected, the engine oscilates a little bit, but runs ok, also smelly.

I don't have a clue if the readings I'm getting are right.
Too lean or too rich?
Any ideas?
Thanks!






Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772

[Michael]

The O2 sensor is not working, if the sensor is new and installed correctly, and dwell hooked up and the diag. port functional, then maybe a bad computer?

[madstudios]

The O2 sensor is not working, if the sensor is new and installed correctly, and dwell hooked up and the diag. port functional, then maybe a bad computer?

Dwell was hooked up in the orange wire of missing port diagnose. O2 Sensor is new and properly installed.
When I disconnect and reconnect the 02 sensor with the engine running, It's noticeable that it has some sort of effect, but I don't know if the lambda system is working properly, I bought the car only 3 months ago, and the car was running with sensor disconnected for a long time I suppose.


Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772

[Michael]

Well before you go looking at the mixture setting you have to make sure absolutely everything is in proper working order. All vacuum leaks corrected, throttle plates set right, make sure the microswitch is working, and about a dozen other things. The mixture is the very last thing to set.

[dmcnc]

The buzzing sounds like the Frequency Valve, which is good. 75 is high. Once at operating temperature and in Neutral (or P for auto) - your dwell gate should swing between 35-55 on 4 cyl scale if your mixture is right and everything else is working correctly. Also, in order to make sure you're getting the right dwell readings open the throttle (3-5 seconds on about 2-3k RPMs) and drop the throttle. You should be able to check your dwell readings at this point.

As for your fuel adjustments, stick to very small increments, repeat the throttle crank described above and check your readings.

[dmcnc]

The buzzing sounds like the Frequency Valve, which is good. 75 is high. Once at operating temperature and in Neutral (or P for auto) - your dwell gate should swing between 35-55 on 4 cyl scale if your mixture is right and everything else is working correctly. Also, in order to make sure you're getting the right dwell readings open the throttle (3-5 seconds on about 2-3k RPMs) and drop the throttle. You should be able to check your dwell readings at this point.

As for your fuel adjustments, stick to very small increments, repeat the throttle crank described above and check your readings.

Correction - your pulse ratios should be 35-45 degrees during normal operations (sensor connected and CO properly adjusted).

[madstudios]

Look what I've discovered today.

Somebody cutted the hose between the valve and oil filler.
I'll buy a new hose and a new oring to the oil filler (it's pretty loose, is it normal?)
Does this interfere on dwell reading?




Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772

[DMCMW Dave]

Look what I've discovered today.
Somebody cutted the hose between the valve and oil filler.
I'll buy a new hose and a new oring to the oil filler (it's pretty loose, is it normal?)
Does this interfere on dwell reading?

Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772

No it would not interfere with the reading. But it would make your oil get dirty much faster than normal. That's PCV suction.

[Jonathan]

Is the CPR on this engine not mounted in the spot one would normally find it?

To me it looks like the CPR is between the end of the A/C compressor and the oil filler / CSV. Is that even possible?

The earlier video to me sounded like there was air leaking somewhere. Either as unmetered air or vacuum or both. I was trying to see if something looked out of place and thought his delay valve seemed to be stretched a bit farther forward than mine is. Or might be plumbed in backwards.

And on another note as I was looking at your video closer... what/where exactly is your thermotime switch plugged into?

Normally it is the one that comes out from underneath the valley and connects to the blue wired cable and white connector right at the firewall below the ballast resistor and then goes in behind to the ECU area behind the driver's seat. It gets easily confused with the connector for the O2 sensor, but the O2 sensor actually comes in below where you can see from the engine bay side and the thermotime switch connector is the higher up one looking from the ECU side. Yours looks like there isn't anything connected to that white connector. What's the deal?

Madstudios engine bay thermotime connector.jpg

[Michael]

Is the CPR on this engine not mounted in the spot one would normally find it?

To me it looks like the CPR is between the end of the A/C compressor and the oil filler / CSV. Is that even possible?

The earlier video to me sounded like there was air leaking somewhere. Either as unmetered air or vacuum or both. I was trying to see if something looked out of place and thought his delay valve seemed to be stretched a bit farther forward than mine is. Or might be plumbed in backwards.

And on another note as I was looking at your video closer... what/where exactly is your thermotime switch plugged into?

Normally it is the one that comes out from underneath the valley and connects to the blue wired cable and white connector right at the firewall below the ballast resistor and then goes in behind to the ECU area behind the driver's seat. It gets easily confused with the connector for the O2 sensor, but the O2 sensor actually comes in below where you can see from the engine bay side and the thermotime switch connector is the higher up one looking from the ECU side. Yours looks like there isn't anything connected to that white connector. What's the deal?

Madstudios engine bay thermotime connector.jpg

Good catch, OK where is the CPR?? Because it sure is not where it's supposed to be. I bet there are a lot of lines blocked off on that one, in fact I have a feeling that car has been hacked to run and a lot of Kjet essentials(incl. Lambda) have been cut out of the loop.