mixture adjustment tool

adjustment tool should not be a problem there, K-Jetronic have a allen key adjustment screw that hits onto the air flap sensor plate thingy...ekkk i think its about 2.5mm or 3mm across the flats, sorry its been awhile since ive looked in one or my tool box for that matter, but the trick is to get a long enough key that will stretch the length downwards so you can get the clearance to turn the top of the tool, best thing to do is to have measure up roughly the length you need, go down to a well stocked autoparts store, ask the parts dude for the longest set of allen keys he has and buy a set, if the parts dude has any wit then tell him its for K-Jetronic co adjustment, if he knows the system then your cooking with gas, if he looks at u like all stupid, then ask a good mechanic if u know any for the allen key that adjust K-Jetronic co mixture adjustment, it cant be that hard to source..k-jetronic have been fitted to sqillions of early injected run of the mill motors, good luck

 

It takes an extra long 3mm allen key.

 

Don't rev the engine with the tool in it! Also, it's opposite from the standard carb mixture adjustment, for K-Jet, turn clockwise from above to richen, counter clockwise to lean the mixture. Always adjust from lean to rich, never rich to lean. IF you have to, go too rich, then come back. Always remove the tool, close the access hole and blip the throttle before measuring CO between each adjustment, an open access hole will throw it off. I think .7% to 1.2% CO before the cats is desirable.

-Peter (glad to use my 25-year-old knowledge!)

 

Lolaman has given great advice, and his pre-cat numbers are very close to what I've been told. (I was told 0.8 - 1.25) Make sure you disconnect the O2 sensors prior to adjusting.

 

I think this is the tool he is looking for, unfortunately I don't remember where I picked it up. Maybe Harbor freight, Autozone, Advance auto parts etc. At least you could show the photo around, maybe someone would recognize it (by brand).
Image Unavailable, Please Login

 

OSH hardware has those, i got a metric set for something like $20. beats paying for the specific tool when it's only a 3mm alllen.

 

Try looking on E-bay, sometimes found under $100.
I got mine for $89
works like a charm.... very simple.. but take a while to warm up

 

I am having the same issue with my 80 308 GTSi....high on the CO count and will not pass CA Smog.
I appreciate the tips on the chat...
Is the GASTESTER a good CO and NO analyzer for home use?
I noticed some of the Fuel Mixture Testers in the Summit catalog required welding a Bung to the exhuast pipe somewhere.

Also, my car is running to rich ( high CO ), and Lolaman stated "Always adjust from lean to rich, never rich to lean. IF you have to, go too rich, then come back". If I am already "too" rich, can I just adjust it back now?
How do I now when I reach a "too rich" condition?

 

per Bosch:

...,turn the CO mixture screw out (counterclockwise) to a value leaner than specification. then, turn the mixture screw in (clockwise) to bring the CO value into specification. always adjust from the lean side when setting CO. after each adjustment....

 

Don't rev the engine with the tool in it!

Do blip the throttle between each adjustment.

-Peter

 

Randy, it doesn't take much to make a big change in the CO. I recommend ONLY using a CO machine (rather than voltage readings from an O2 sensor or your nose <grin>)

If you want, try turning 1/16 of a turn counterclockwise and see if idle quality improves. If it does, you're going in the right direction. You'll need the meter to eventually determine where you are, though...

There is a tap before the converters on these cars, after the collector, before the converter. I use a 3/16" metal brake line, making sure it doesn't bottom out in the exhaust pipe. Then, a hi-temp rubber hose from the probe of the CO machine to the metal line.

I like the D-Jaye, myself.

-Peter

 

when i did mine it was a bit of a pain, well more time consuming than anything. set the CO,easier than it sounds becouse on the CIS you have to adjust for the richest injector so you run the risk of going lean, so it's a back and forth between the ports. then with that done it's time to adjust the idle, another circle exercise. not that it's impossible but it is time consuming. it's no wonder most shops won't bother, took me 2hrs to get it right. after that she ran great, and now that i pulled out the motor and replaced the injectors i have to do it all over again.

 

I ended up buying a 4-gas analyzer (older sun unit) with the sniffer wand up the tail pipes. It wasn't cheap despite being a 15 year old machine. But it works extremely well after it's 10 minute warm up period. Adjusting the mixture on my TR is just as described previously, it's like a dog chasing it's tail and getting closer at every turn. I find that your never extacly set on one parameter before moving on to another, they all have some overlapping effect on each other. But once things are set, these CIS systems stay put. Very very reliable, although a bit complicated and not the best for performance. These systems were used by Ferrari to pass stricter emissions and not really for performance. Once EFI was used it really opened the door for more horsepower. Actually considering the distance and directional changes the incoming air has to make in these systems, Ferrari got pretty decent horsepower out of the motors. But these CIS systems don't cope well with radical cams and such due to some kind of "reversion" or pulses back through the intakes. What the.....oh.....I'm sorry to ramble on and on....I get carried away sometimes. And that's exactly what my girlfriend says is gonna happen to me some day!

 

Yes I have the Digital Gastester (not the pro model)

its small, light, and works as designed, a bargin in my opinion.

I think you can go to their website and download the user manual.

here is a resellers link with a link to the user manual..

http://www.aep.bigstep.com/digital1.htm

 

That sounds like the way to go....
I have done an extensive internet search and so far have only found them in the UK. Northern Tool is out of stock in the US.
If anyone knows where I can buy one in the US, let me know.

Also, I saw on another chat forum that a guy replaced his O2 sensors and it helped alot on the CO count.......any truth to that???

Randy

 

sure. A properly working lambda system will adjust for all sorts of minor problems (vacuum leaks, slightly incorrect base mixture setting, wonky WUR, etc). The feedback from the O2 sensor is used to continually adjust the mixture, and the intent is to keep the exhaust gases in a range that the cat can easily handle.

however, if your case, an O2 sensor isn't going to help....you don't have one

the consensus seems to be that just being able to measure CO isn't really ideal. You can get CO really low, but then fail NOX. It's probably a lot more cost effective to just go to a place with a 3+-gas analyzer and flip them a few bucks to hook your car up while you tweak the mixture screw.

 

The reason why you can achieve a low CO reading, yet fail HC and Nox, is because of a lean misfire.

That is why it is important to not treat the symptoms (by replacing the O2 sensor(s) and expecting the car to blow in the proper range if it has not before), but to treat the disease by disconnecting the O2 sensors and allowing the system to go into a stable, "open loop" feedback mode, set the CO to the proper, specified range (.7%-1.2%) and reconnect the O2 sensors after you verify that the system is capable of being adjusted to a stable mixture in the first place.

I have often seen fuel distributors set too lean and the poor O2 sensors trying desparately to richen it up, so much so that the car develops an irregular "hunting" idle and will NOT pass HC. It almost seems counterintuitive to richen the mixture of a car that already has too much HC (unburned fuel), but if the CO, as measured before the cats is on the low side (.2%-.5%), try that first.

-Peter

 

I saw them on the SNAP-ON and Mac Tool sites, but didn't want to wait for mail order. I ended up buying a set from my local Sears for $21 that included 3 mm. Craftsman model #46298

 

OK....She finally PASSED!!! With flying colors I might add.....
I bought the 3mm long hex wrench at OSH Hardware in a set for $29.99. The mixture screw is located between the fuel pump ( spider ) and the air cleaner..you really have to look it since it is partially covered by the air cleaner.
I removed the cap screw with a long 3/16" flat blade screw driver ( make sure it is magnetized so you don't loose the cap screw upon lifting it out!).
With the car running, I turned the hex screw counter-clockwise until the car stalled ( too lean, approximately 1/3 of a turn ). Restarted the car and adjusted the hex screw clockwise until the car ran without mis firing ( about 1/8 turn only ). I took the car out and ran her hard for an hour, she did pretty good but not as good as when it was running rich.
I went to the Smog Test Only statiion and wah-la, she passed with .01% CO (allowed 1.42%) and NO went up to 432 ( 1253 allowed ).
Now I will retune back to a richer condition, but not as rich as it was before.
Thanks for all the advice.....I never did get a Exhaust Analyzer due to my impatients! I reverted to my "old school" basics of "tuning by ear" as I have always done on my American muscle cars. Thank God they don't need Smog anymore!