Need Bosch Part No for Mondial 32 O2 Sensor

Joe: I don't need a 5-gas.....however, it will be easier to sell, when I want to upgrade in a few years. Besides, the price was right!.....the list price is almost $5,000.....but they will deal, if you are ready to buy right then and there.

>>Viva Ferrari - Talk !!!!<<

Well, Ferrari is useless at growing the next crop of Ferrari Machanics, so we might as well do it here...{}...actually better and easierto learn in a propaganda free learning environment anyway imo.

OK back to "settings".

In order to set idle CO on the K-Lambda Systems certian procedures should be adhered to for best results.

1) warm engine, remove test plug before cat, remove FD plug (Fuel Distrib Plug) and insert plastic or rubber stopper in adjustment access hole.

2) connect Gas Analyzer, start engine, disconnect Oxy Sensor wire (green)..Take Readings

3)Pull stopper and with 3mm allen adjust CO to 0.8% - 0.9% CO..replace stopper and check...(mixture will change as air leak is plugged), reset again closer this time

4)when mixture is right at 0.7%-0.9%CO with stopper in place, reconnect Oxy Sen wire and recheck

5)double check to insure Oxy Sensor now stabilizes the mixture ...repeat above as neccesary to fine tune for lowest HC's (without causing the O2sen to overcorrect)

The above is very important to prevent the O2 sensor and Computer/Frequency Valve from fighting each other or trying to work beyond their intended limits of correction.

HTH's

note: it might be possible to adjust CO by monitering Duty Cycle, never tried it, but I'm sure this would be a huge PITA even if itis possible.

Hello JR,

Thanks for the procedure. I will utilize it once I get the EGA. I got it printed out ready to go.

Some of the Bosch books say you can use the duty cycle of the Freq valve to adjust CO (as an alternative) (someone on that other board was doing that thinking it's correct but it's not the best/right way)

I don't want to use the Freq valve either because it seems like using an O2 sensor (which sends a signal to the ECU to change the freq. of the freq valve based on O2 content) to adjust for CO means an error on top of an error (not super accurate, sorta mickey if ya know what I mean, chasing the error)

Thus I agree. CO baseline must be set with a CO meter. Then check to see if everything else is doing its job in harmony correctly.

Joe,

a question. you peeked my interest in being able to set CO wuth duty ctcle.

Can you actually watch/see the duty cycle change as you change the mixture settings manualy?

Hello JR,

you asked >Can you actually watch/see the duty cycle change as you change the mixture settings manualy? <

yes
- Engine warm, closed loop
- Hook up a test connector between the connector/harness that plugs into the freq valve and the freq valve connector that gives you some bare wires to attach some lead to (in other words, you want it to operate as normal but you want to be able to tap into both wires )
- using a dwell meter set to 4 cyl scale, connect the two leads of the dwell meter to the two wires of the Freq valve

- the dwell meter should swing back and forth between 45 - 55 % if everything is set correctly and operating within range
(above 60% duty cycle i.e. the system is trying to correct for too lean a mixture)
(below 40% duty cycle i.e. the system is trying to correct for too rich a mixture)

I never had much success with a dwell meter so I used a hand held oscilliscope (about 6 years ago).

** it matters which wires from your meter connect where. In other words, if your reading a 43 % duty cycle and you switch the wires it would then read 57%...so you need to be on the correct wires to your dwell meter or you're reading the inverse duty cycle ("off time" i.e. not "on time" which would then be incorrect)
So you need to figure out which wire goes where. i.e. force a lean condition and make sure you get a reading below 45% then you know that's the correct way.

(you're right, it's a pain in the ass to get right)

Then, once everything is hooked up and the engine is running, as you turn the 3mm adjustment screw clock wise and CCW you'll actually see the dwell meter (aka duty cycle) change. The key is to than get it to oscillate between 45% to 55 %

The problem with this whole method is (just one of many in my opinion), if you have for example a failing O2 sensor sending a bad signal to the ECU (low output i.e.), you're then gonna think you need to make up for it by cranking up the CO and what you're really doing is over-enrichening (off baseline).
A 5 gas analyzer wouldn't let you do this.

That's why after you had taken the time to help that guy on FC to tweak his CO using an EGA, and then he goes and does it using the duty cycle method and still gets poo poo results...blew my mind why he went and did that...but oh well.

The O2 sensor senses Oxygen. Why would you wanna use that to tweak CO if you had a EGA? (2 diff. gasses)

But, as you adjust CO, the pulse frequency on the freq valve changes anywhere from 5.1 KHz to 9.5 Khz (or something like that, I can't remember exactly...that's what's happening ...but with a 5 Gas EGA who would care cause your reading the final results which is what truly matters)

All this is written up in several Bosch manuals.
I tried using this techinique on a 1984 308qv I had but it never truly got the car dialed in, some guys still do this but I think they're missin' the boat.

My 3.2 still has virgin plugs on the Fuel Dist....but that will all change once I get my 5 gas EGA

correction
I wrote >So you need to figure out which wire goes where. i.e. force a lean condition and make sure you get a reading below 45% then you know that's the correct way. <

I should have said > reading above 60%

(it was late ) sorry

Other drawbacks to this technique that have come into my mind
- you're trying to hit the exact CO spot while the needle is oscillating between 45%-55% - tricky

- and, you have to have a perfectly functioning O2 sensor or you'll make a over correction


(I had hooked up my scope yesterday just to check/verify that what I was seeing on the O2 was indeed the case)