Mixture settings using a Digitla TRUE RMS Metter.

[norcimo]

Ok, next step. Stop the idle hunting and bad smell of gas.. I know its running rich.. I can recognize the smell

I bought I digital meter 39737.


Please advice what values am I looking for. My understanding is that , with a digital meter, you may get double in comparison with a analog.

SO I adjusted accordingly. Idle hunting has stopped, and its not running rich anymore, the smell went away, and the exhaust is almost invisible.

Still I would like to know.

Thanks

[Michael]

Ok, next step. Stop the idle hunting and bad smell of gas.. I know its running rich.. I can recognize the smell

I bought I digital meter 39737.


Please advice what values am I looking for. My understanding is that , with a digital meter, you may get double in comparison with a analog.

SO I adjusted accordingly. Idle hunting has stopped, and its not running rich anymore, the smell went away, and the exhaust is almost invisible.

Still I would like to know.

Thanks

I always had trouble with a digital because the swing was too hard to decipher using just changing numbers, but it will work just the same.

[Bitsyncmaster]

Most multimeters used for electronics will read duty cycle backwards from what an automotive meter will read.
.
So you set the switch for duty cycle (you use the "select" button to switch from Hz or Duty). Then verify the reading when you press the wide open throttle switch. Pressing that switch will force the duty to 60%. If your meter reads 40% than it's backwards from the automotive values.

Normal closed loop duty should be swinging around 44%. If your meter is backwards you would set it swinging around 56%.

Reversing the test leads usually does not make the meter read correctly but you could try that test with your meter.

[norcimo]

Most multimeters used for electronics will read duty cycle backwards from what an automotive meter will read.
.
So you set the switch for duty cycle (you use the "select" button to switch from Hz or Duty). Then verify the reading when you press the wide open throttle switch. Pressing that switch will force the duty to 60%. If your meter reads 40% than it's backwards from the automotive values.

Normal closed loop duty should be swinging around 44%. If your meter is backwards you would set it swinging around 56%.

Reversing the test leads usually does not make the meter read correctly but you could try that test with your meter.

I know I'm still off... even though it idles great and no more smell, you step on the gas and it putters...

when I switch to duty on the meter, its says 10% 11%. 10% cycles... I know I'm off.

[norcimo]

Most multimeters used for electronics will read duty cycle backwards from what an automotive meter will read.
.
So you set the switch for duty cycle (you use the "select" button to switch from Hz or Duty). Then verify the reading when you press the wide open throttle switch. Pressing that switch will force the duty to 60%. If your meter reads 40% than it's backwards from the automotive values.

Normal closed loop duty should be swinging around 44%. If your meter is backwards you would set it swinging around 56%.

Reversing the test leads usually does not make the meter read correctly but you could try that test with your meter.


Where is the throttle switch?

Thanks
pic please.

[Bitsyncmaster]

Where is the throttle switch?

Thanks
pic please.

There is a micro switch mounted near the throttle spool. Then a little arm on the throttle spool would actuate the switch when your at wide open throttle. Just press that micro switch lever to turn it on.

[Bitsyncmaster]

I know I'm still off... even though it idles great and no more smell, you step on the gas and it putters...

when I switch to duty on the meter, its says 10% 11%. 10% cycles... I know I'm off.

Yes if everything is working those numbers tell your still not adjusted correctly.

[DMCMW Dave]

Yes if everything is working those numbers tell your still not adjusted correctly.

Again, assuming your meter works and it is hooked up correctly, that mean it is set too rich. Which doesn't exactly match your symptoms, so you likely have other issues.

Are you hooking the meter to the metering test lead (orange wire) or bridging the frequency valve?

[Bitsyncmaster]

Again, assuming your meter works and it is hooked up correctly, that mean it is set too rich. Which doesn't exactly match your symptoms, so you likely have other issues.

Are you hooking the meter to the metering test lead (orange wire) or bridging the frequency valve?

Forgot about the possibility to hook the meter up on the frequency valve but I think it will read the same as the orange wire. So you have to test with the WOT switch to get your reading of 60% first.

Duty cycle will read values 10% higher than the book dwell numbers. So the book 40 deg. setting would be the same as 44% duty cycle.

[norcimo]

Digital meter was too complex.

Got my self a analog dwell meter on Amazon that has a scale for 4 -6 -8 cyl.

I saw a video on youtube of a meter holding very steady at 21 degrees
... this does not seem right..

the book says its suppose to be 38-45 ..(correct me if I'm wrong)

My meter has a 6cly scale, and when set the mixture to exactly like the video, its does not idle well at 750RPM.

I had to make 900 -1000...I know this is not right.

So I went down to 750 -775, I adjust the mixture and till the needle goes up and down over 38-42 average over the 40 mark, I can idle 750 smoothly and the engine works great, no rich smell, no idle hunting.. so which one its suppose to be? steady needle at 21.5? or the alternating over 38-42.. is the video misleading?

Thanks

[sdg3205]

Digital meter was too complex.

Got my self a analog dwell meter on Amazon that has a scale for 4 -6 -8 cyl.

I saw a video on youtube of a meter holding very steady at 21 degrees
... this does not seem right..

the book says its suppose to be 38-45 ..(correct me if I'm wrong)

My meter has a 6cly scale, and when set the mixture to exactly like the video, its does not idle well at 750RPM.

I had to make 900 -1000...I know this is not right.

So I went down to 750 -775, I adjust the mixture and till the needle goes up and down over 38-42 average over the 40 mark, I can idle 750 smoothly and the engine works great, no rich smell, no idle hunting.. so which one its suppose to be? steady needle at 21.5? or the alternating over 38-42.. is the video misleading?


Thanks

The Actron meter? Use the 8 cylinder scale and double the values. I tweak it to swing between 20 and 25 (so 40 and 50, with an average of 45).

A steady needle means the lambda system is not running a duty cycle and you're beyond the range it can handle. This is called "open loop." When the needle swings, it is running "closed loop" which is a range within the capacity of the system, but not necessarily where it ought to be. You can be closed loop but running either too rich or lean.

If you're mixture is now way out, start from scratch, recrack the injectors to re-establish baseline, fire up the car, let it get to OPERATING TEMPERATURE and try again on the 8 cylinder scale.

Setting the mixture takes some practice and patience. You'll figure it out.

Here's (https://www.youtube.com/watch?v=tTw7zpipaPs) a video that shows both dwell and duty cycle simultaneously.

[Bitsyncmaster]

Setting the closed loop book value of 40 deg. requires you use the 4 cylinder scale.

When your running closed loop (dwell reading varying) you probably have the correct fuel mixture at that moment but if the dwell is not averaging 40 deg. then your engine will not maintain the correct mixture when starting, warming up, altitude changes, etc.

[norcimo]

The Actron meter? Use the 8 cylinder scale and double the values. I tweak it to swing between 20 and 25 (so 40 and 50, with an average of 45).

A steady needle means the lambda system is not running a duty cycle and you're beyond the range it can handle. This is called "open loop." When the needle swings, it is running "closed loop" which is a range within the capacity of the system, but not necessarily where it ought to be. You can be closed loop but running either too rich or lean.

If you're mixture is now way out, start from scratch, recrack the injectors to re-establish baseline, fire up the car, let it get to OPERATING TEMPERATURE and try again on the 8 cylinder scale.

Setting the mixture takes some practice and patience. You'll figure it out.

Here's (https://www.youtube.com/watch?v=tTw7zpipaPs) a video that shows both dwell and duty cycle simultaneously.

Yes, ACtron Meter.

Thank you.. I knew it was not perfect.. was ok, not exactly where it suppose to be. I will make video and post the results.

[norcimo]

The Actron meter? Use the 8 cylinder scale and double the values. I tweak it to swing between 20 and 25 (so 40 and 50, with an average of 45).

A steady needle means the lambda system is not running a duty cycle and you're beyond the range it can handle. This is called "open loop." When the needle swings, it is running "closed loop" which is a range within the capacity of the system, but not necessarily where it ought to be. You can be closed loop but running either too rich or lean.

If you're mixture is now way out, start from scratch, recrack the injectors to re-establish baseline, fire up the car, let it get to OPERATING TEMPERATURE and try again on the 8 cylinder scale.

Setting the mixture takes some practice and patience. You'll figure it out.

Here's (https://www.youtube.com/watch?v=tTw7zpipaPs) a video that shows both dwell and duty cycle simultaneously.

here is 06097 dwell

https://www.youtube.com/watch?v=61kDXnjQJSY

Thanks

[norcimo]

Yes, ACtron Meter.

Thank you.. I knew it was not perfect.. was ok, not exactly where it suppose to be. I will make video and post the results.

one last question,

is this suppose to be done with the O2 sensor disconnected?

[Bitsyncmaster]

one last question,

is this suppose to be done with the O2 sensor disconnected?

You have to have the whole lambda system working to adjust mixture via dwell readings. So yes the O2 sensor has to be connected.

[spikeygg]

Would someone please post a link to the dwell meter that works? I've been hunting for an analog actron meter but I haven't been able to find one... Just looking for a meter that will work well for this application. I have a fluke but there are no frills. ��

Thanks!

Edit
Nevermind, I found it and bought it from eBay: http://m.ebay.com/itm/Actron-CP7605-Dwell-Tach-Volt-Meter-Tester-RPM-Ignition-Dwell-Angle-Analyzer-/401172479360

[David T]

Would someone please post a link to the dwell meter that works? I've been hunting for an analog actron meter but I haven't been able to find one... Just looking for a meter that will work well for this application. I have a fluke but there are no frills. 😔

Thanks!

You should try to get an old analog dwell meter with an actual meter that has a needle. Because you are trying to measure a modulating signal a digital meter won't give you proper readings since it is constantly changing. You should not have to spend much and can find one at any car show that has vendors that sell old stuff. You should not have to spend more than $10. To get a graphing digital meter will cost you a lot more.

[Ron]

Would someone please post a link to the dwell meter that works? I've been hunting for an analog actron meter but I haven't been able to find one... Just looking for a meter that will work well for this application. I have a fluke but there are no frills. ��

Thanks!


$25.00+S&H
http://www.ebay.com/itm/Actron-CP7605-Dwell-Tach-Volt-Meter-Tester-RPM-Ignition-Dwell-Angle-Analyzer-/401172479360?hash=item5d67be3d80:g:ldsAAOSwLF1X4uD w&vxp=mtr

[spikeygg]

You should try to get an old analog dwell meter with an actual meter that has a needle. Because you are trying to measure a modulating signal a digital meter won't give you proper readings since it is constantly changing. You should not have to spend much and can find one at any car show that has vendors that sell old stuff. You should not have to spend more than $10. To get a graphing digital meter will cost you a lot more.


$25.00+S&H
http://www.ebay.com/itm/Actron-CP7605-Dwell-Tach-Volt-Meter-Tester-RPM-Ignition-Dwell-Angle-Analyzer-/401172479360?hash=item5d67be3d80:g:ldsAAOSwLF1X4uD w&vxp=mtr

Ha-ha I beat both of you by just a couple of minutes... $26 shipped.