CIS testing - Dwell meter

[wichitaguy57]

I have a Sears Engine Analyzer (Model 161.216300) with red, black and green connectors plus an RPM plate. It also has a Range selector Dwell ( 0-100rpm) or Points( 0-6000 rpm, Low voltage). A Function Selector dial for Volts, Amps, Dwell/Points, 4 cyl, 6cyl, 8cyl. This unit is old, but new in the box.

Red connector to the rear fuse panel
Black connector to ground
Geen to the pin connected to the Green/w white on the test plug

Range selector set to Dwell
Function Selector set to 4 cyl.

I'm not getting any of the test values I would expect.

With the Range selector set to Dwell, the needle goes to around 10 on the 4 cyl scale
With the Range selector set to Points, the needle goes to around 30 on the 4 cyl scale.

Black connector to test plug green w/ white, the meter is pegged with the range selector set to Dwell.

Is the setup wrong or is the unit faulty?

Thanks in Advance,
Guy

[Scott R]

On my meter it's black to ground, and red to the green/white on the diag plug in the engine bay.

[5String43]

Green to the pin connected to the Green/w white on the test plug

Ah, this leads to a question I've been meaning to ask. Where, exactly, is the Lambda test plug to which we're advised to hook one of the dwell meter leads? I mean, precisely? I've looked on the inside left of the engine bay and flat don't see anything that looks like it. A photo would be good, probably.

Thanks in advance - Jon (Oh, and I don't mean to hijack this thread.)

[psalt]

Guy,

Your hook up is correct, make sure the green alligator clip is not touching any of the other pins. What does it read if you turn the knob to volts ? If the meter is unknown, I would try it on a points ignition car to see if the dwell function works. Do you have a good O2 sensor and can you tell if the system is going into closed loop ? The idle should fluctuate when hot and the switch on the right timing chain cover is open.

[Bob Kontak]

For 5String43. It may be buried under the relay panel.

[wichitaguy57]

Success !!

On this model setting the Range selector to Dwell and the Function Selector to Dwell/Points works using the 4 cyl scale on the meter.

Scott R: Black to the Pin - Green w/white wire is WRONG. Sorry, you're correct. Black to ground, Red to the fuse panel and green connector to pin for this model. I didn't try Red to Pin.

Paul: Thanks for getting me to play with the switches. Yes, I going to closed loop which I see with the dwell meter plus looking at the voltage from the oxygen sensor. Tested the 15 degree switch yesterday so I know that is good. Your input into the CIS subject across the board has been most helpful!!!

I've been following a number of the CIS threads in order to cleanup a rough idle at start up. Fuel pressures are good, WUR is good, AAV is good, tested vacuum with carb cleaner. Didn't find anything, but I'm still not sure. FV has voltage, hums and vibrates although it doesn't kick in right away.

I replaced the O2 sensor when I replaced a chain tensioner. Retimed and then things started to get worse. I suspect the PO may have had done something to the mixture to compensate.

The car is a 83 911SC

[5String43]

Bob, thanks very much. It's right where you predicted it would be. But I find when I look at my old dwell meter that its leads are two in number - red and black. I imagine this renders it unusable for this function, no?

Thanks-Jon

[boyt911sc]

wichitaguy,

Check your ignition timing, fuel pressures, and air leaks. Adjusting the fuel mixture without verifying the integrity of the vacuum system (air leak) is the most common mistake by most DIY'ers. Here is an example of an engine the owner claimed not to find an air leak using a carb cleaner.


CIS is very sensitive to air leak/s causing the mixture to go lean. So making the mixture richer is a band-aid solution instead of fixing the root cause of the problem.

Tony

[wichitaguy57]

Tony: can you send me your procedures for finding vacuum leaks? I PM'd you, but never heard back. Hope all is well.

[boyt911sc]

Originally Posted by wichitaguy57

Tony: can you send me your procedures for finding vacuum leaks? I PM'd you, but never heard back. Hope all is well.

Guy,

I have already composed the procedure (air leak detection for CIS) with pictures for you and a couple of members last week but I forgot to forward them. I'll retrieve the instruction and forward it to you ASAP.

Tony

[labdag]

Hi Tony and team, it's been great reading through your posts. I'm a newbie and a first time proud owner of a beautiful 1983 911 sc. I'm looking forward to provide the best care I can.

Would it be possible for you to please share your leak detection procedure with the rest of us or via email.

Reason being: insert key into ignition turn to position 2, it makes a buzzzzing sound (coming from the dash not sure why), starts car ( starts up right away), but them stutter during idle. I have to keep feet on accelerator of 5 mins before I can drive. The car is kept in temp control garage around 72 degrees. Trying to understand reason for this action. Thus hoping to identify leaks.

Thank you
Romel

[LM3929]

Tony, could I get a copy of those test instructions?


Lorne M.

[arbita1]

Tony,

I'd love to see a copy as well if possible.

I'm sure alot of people would find it usefull. Maybe you should see about making a it tech article on the site.

[boyt911sc]

Romel/Lorne/Matt/ et al,

I had demonstrated the procedure several times in my previous posts. The test takes about a minute and you're done. Since a lot of CIS owners wanted to have the procedure documented, I'll prepare one for the community. Once I located the culprit for the battery drain in my son's '87 Carrera, I'll have the procedure posted very soon. Hope this helps others.

Tony

[arbita1]

Originally Posted by boyt911sc

Romel/Lorne/Matt/ et al,

I had demonstrated the procedure several times in my previous posts. The test takes about a minute and you're done. Since a lot of CIS owners wanted to have the procedure documented, I'll prepare one for the community. Once I located the culprit for the battery drain in my son's '87 Carrera, I'll have the procedure posted very soon. Hope this helps others.

Tony

Is this the pressure test with compressed air? I've seen you mention it before, but I don't think I've ever seen an explaination of exactly how to do it. I'll await your write up.

[56 nomad]

Originally Posted by boyt911sc

Romel/Lorne/Matt/ et al,

I had demonstrated the procedure several times in my previous posts. The test takes about a minute and you're done. Since a lot of CIS owners wanted to have the procedure documented, I'll prepare one for the community. Once I located the culprit for the battery drain in my son's '87 Carrera, I'll have the procedure posted very soon. Hope this helps others.

Tony

tony , not trying to hijack but it seems a simple answer...i cant get a reading with my sears unit and it works on my old chevy...i have heard that sometimes you need another source for power, one that hooks up at the battery or has an internal battery, is that true? am i doing something wrong...green plug to white and green wire and black to ground.....no reading thanks ben

[arbita1]

I had one like that (different brand) and could never get it to work. A couple other people had the same issue with it. I was never able to figure out why, but I think you may be right.

I ended up getting a craftsman digital multimeter that also reads duty cycle. Works great. The only issue is that it reads the positive slope and lambda works on negative slope. So I have to subtract my results from 100 to get the correct reading.

[56 nomad]

Originally Posted by arbita1

I had one like that (different brand) and could never get it to work. A couple other people had the same issue with it. I was never able to figure out why, but I think you may be right.

I ended up getting a craftsman digital multimeter that also reads duty cycle. Works great. The only issue is that it reads the positive slope and lambda works on negative slope. So I have to subtract my results from 100 to get the correct reading.

which did you get , theres one on ebay a sears multi tester has to be hooked up the battery to work...old analog unit..funny thing was once i got a reading from my meter but it dropped of slowly????? never to be seen again!!! want to set the thing so i can try to get it closer for smog test.
when you use the digital ( cost?) is it hooked up the same way...only difference is the subtraction thing? ben

[arbita1]

Originally Posted by 56 nomad

which did you get , theres one on ebay a sears multi tester has to be hooked up the battery to work...old analog unit..funny thing was once i got a reading from my meter but it dropped of slowly????? never to be seen again!!! want to set the thing so i can try to get it closer for smog test.
when you use the digital ( cost?) is it hooked up the same way...only difference is the subtraction thing? ben

I have this one.

Product

The red hooks up to the green plug, and the black hooks up to a ground. Some people say the analog ones are better because its easier to see a needle swinging than a digital read out. I'm okay with it.

[Bob Kontak]

Originally Posted by 56 nomad

am i doing something wrong...green plug to white and green wire and black to ground.....no reading thanks ben

Post the type and model number of your dwell meter or post a picture of it.

We need to get to the bottom of this so get me the data. You have been struggling with this for weeks. Take it off line with me if you wish but there is something wrong in the basics.