Efffff the Mighty Actron - wut youse need is something like this . . . mounts between the seats (to a rod on the parking brake lever), or pick it up and move it to the dash mount for better visibility while boosting. Getcha summmmm! :D

http://forums.pelicanparts.com/uploa...1437195105.jpg
http://forums.pelicanparts.com/uploa...1437195137.jpg
http://forums.pelicanparts.com/uploa...1437195160.jpg
http://forums.pelicanparts.com/uploa...1437195179.jpg

Ronnie what kind of cash have you got sunk into that bad boy?

If it weren't for the inductive voltage 'ringing', i.e. the multiple high voltage spikes,
when the frequency valve is switched off, any voltmeter would provide good
voltage readings to calculate the actual duty cycle. Any device used to determine
the duty cycle needs to 'ignore' the voltage spikes in its measurement. Obviously
when using an o-scope, one can just measure the on/off times of the frequency
valve and calculate the duty cycle.

Update on this. I bought Louie's male OXS connector plug and installed it, since mine had disintegrated. I cleaned up the wire connection, but left a little unshielded wire since I figured it made no sense to shorten the wire any more than I had to; any interference from a length of unshielded wire was going to be similar to the interference from the unshielded connection between the wire and Louie's connector (which is nicely made, IMO).

Car is idling differently. Not better or worse, just differently. So I think I was having a connection issue on the OXS. Also, the smell of gas in the exhaust is stronger than I remember it, so I'm thinking we're running a little rich now.

Going to check fuel pressure, then vacuum leaks (again), then set timing, then check duty cycle. Will let everyone know what I find. Suggestions welcome.

Good idea to replace the connector. Louie85 makes a great product.

Hi Jason, I seem to remember a thread that described the method for installing the new connector. As I recall you had to be quite careful with how you install the shielding (needed ground?) around the coax. It should be pretty easy to test if the OXS box is getting input from the sensor.

You've probably already read this but will place here for convenience:

http://forums.pelicanparts.com/porsche-911-technical-forum/497025-o2-sensor-connector.html

My OXS was kaput and it turned out to be just the sensor itself. My car smelled very rich at idle too. Once I replaced the sensor it smelt much better. I believe the system just turns full rich with O2 connected but non functioning. This is different to just having the sensor disconnected all together. I'm probably just telling you stuff you already know.

mysocal911 -> thanks for the input! I guess the most accurate way is to use the o-scope and calculate it.

Perhaps trying the 3MM screw is an option rather than pounding on the dwell meter as a POS. I don't need to defend it but it has not been given a chance.

See setup for metal line 3mm screw below.

Do you guys know which way to turn it for lean? Whatever you do, do it in 1/16 turn increments followed by a slight clockwise turn to set the threads.

http://forums.pelicanparts.com/uploa...1437602423.jpg

Using the "tennis ball and shop vac and soapy water" test, I found no vacuum leaks. That doesn't mean there aren't any...just that I didn't find any. Next up is to look at fuel pressure, but I need a fitting for my FD that I don't have. Does anyone know offhand what the right size fitting is for the connection to the FD? M7 female?

PS gonna try to compare my MM dwell reading with the MA (Mighty Actron). I'll report back or post pics of the smashed MA.

If you put a hammer through yours I can send you mine to see if you get a better result.

I just tried my MA finally and I can't get it read above 7 on a stone cold engine. It is high 80's ambient here in Atlanta though.

gazzerr testing the MA using the balloon theory.

http://forums.pelicanparts.com/uploa...1437606874.jpg

Fuel pressure test.........
 

Jason,

The fittings for the FD head are 8 mm x 1.0. I would recommend that you do the installation of the pressure gauge kit at the WUR side instead of the FD side. At the WUR side, you would need a 12 mm x 1.5 fitting which are very common. Second, it is more convenient to do the installation at this end than at the FD end. And when you remove the WUR in some cases, it is easy to break the fuel lines for removal.

You could do it at either end. There is no right or wrong side. It is a choice and since you are having problem finding the correct fitting for the FD side, using 12-mm x 1.5 should be easy to find. This is the same size fitting for CIS injectors. So you should have plenty of fitting in your kit. Have you tried the WUR side before? Keep us posted.

Tony

Will instruct shortly as to dwell.

L(eft)=lean. R(ight)=Rich

Thank you, Rich.

When you get in there every three years and fiddle, one forgets.

I hope to make a video tonight of richening my CIS. I want to see if I can replicate the sub 10 on the 8 cyl scale.

That may lend some hope.

Bob - HA - very good.

Can there be any correlation between a bad WUR and low readings on the MA?

I can't claim that perm though :).

I would think yes.

We don't know if your screw has been jacked with for various reasons.

All I want to do is see if I can replicate your symptoms with my 3mm screw. It is not the answer. It may be, but you don't yet have the pieces of the puzzle confirmed (i.e., fuel pressure)

Edit: and with experience, you will see it is a relatively simple puzzle.

Hey Bob,

Yes definitely - Tony's gonna test my WUR also given the low resistance. Given my air leaks I have been chasing and fixing I would be willing to bet a full .25c that the 3mm screw has definitely been jacked with. The plug has been drilled out on the top of the FD. :)

Thanks very much for trying on your car. I'm excited to see what you get.

I'm going to test fuel pressures as soon as I can and I will post here.

FYI - All I did on the screw was cut off a piece of 3MM allen wrench stock. Drilled a hole in the end of a chubby allen head screw (cap screw?) and JB Weld epoxied it in. So much easier to navigate around the metal lines.

Back to basic........
 

Gazzerr,

The first thing you have to confirm or verify is the absence of a significant source of unmetered air going into the system. That fuel mixture screw should never be touched or adjusted in the first place. Once it has been tinkered from factory setting, you lost it calibration already. This is the main reason people are having so much problem with CIS troubleshooting. Someone posted a thread on how to adjust fuel mixture with gauges and it is a good procedure. But the author failed to mention that unmetered air should first and foremost eliminated or corrected before attempting to make such adjustment. The post was so old that the author could not edit any longer and became a standard procedure for other troubleshooters.

I have a pretty good success in CIS troubleshooting and the last thing I would do is tinker the mixture screw without testing and verifying the absence of unmetered air going into the system. No gas analyzer nor dwell meter could fix the erratic performance of your CIS engine if you have a significant amount of unmetered air.

Not being able to locate the source of a vacuum leak does not mean you don't have any. So test and confirm. What good would a good working WUR could do if you have vacuum leak. BTW, anyone suggesting to use starting fluid or carb cleaner to locate this illusive air leak is not a CIS guy. And most of the time, you would fail to locate this leak using the volatile liquid. There is an efficient and better method to locate this hard to find air leak/s in CIS engines.......pressure test.

Tony