On the CIS fuel distributor / air flow meter assembly, I've read there were 3 different sizes of air flow plates (the round disc inside) offered as stock systems. Does anyone know the diameters and origins of them?
Without doing some research and digging through my parts stash I couldn't tell you the diameters.
They are all around 80mm.
As for the plates, it is not just the diameter but more so the metering cone and the cone design.
Early VW's had smaller plates with steeper cones, this was a compromise of power and economy.
Later VW's had larger plates (~2-5mm larger) and the cones had three transitions, Idle, mid range, and wide open throttle.
16V 1.8's shared the same geometry
16V 2.0's had larger plates and a more aggressive cone transition, these were primarily for the larger breathing flow and higher RPM of the 16V's
5 cylinder VW's had the same cone and plate diameter as the 2.0 16V's but a different meter and mounting configuration.
As for your question, why do you ask?
Are you after a replacement, or more power?
I might be able to help more if you could elaborate.
My browser has the CIS threads pinned, so I saw this posting and thought I would share some of what I knew off the top.
If you curious and have time to read, my signature has a lot on CIS-(E) in it and the many iterations I went through tuning/experimenting in CIS technology.
It is very long worded but there is some content you might find interesting or informative in a trial and error approach to understanding CIS.
I am trying to identify exactly which air-metering unit I have (it is not original to the vehicle nor engine), and which ones are compatible with the fuel distributor/other components I have (nothing I have is complete or matching). Basically this 'basket-case' vehicle came with some boxes of parts and I'm finding out many of them are not for the car.
I've read there were 3 sizes of plates used on Mk1 CIS (basic and Lambda). I am not concerned with CIS-E, Motronic, etc, etc, etc...only the US version early stuff.
I believe the '83-'84 GTI had a larger plate (actual size unknown) but all other FI components were the same as the other Mk1's. I do not know what the third size plate was from. And I don't know the actual sizes of any of them. Nor do I know what other system parts are compatible with which plates (consider everything as a separate piece).
Any info to offer? Thanks.
How about indicating the year and model? If you have boxes of meters and plates, you sort of need to know a little about CIS-E, CIS-Motronic.
I have two MK1 GTI's
Both of those take the larger "European" cone and the distributor is black, not silver with the Lambda control valve and fuel filter integrated in the airbox assembly.
Here is an example of a "Black" GTI Meter and Plate.
Do some other searches and see what come up to differentiate for yourself with your box of parts.
Or post/search against the Metal Stamped part numbers on the sides of all the meters and see what comes up.
But the above was good information even without the dimensions for, CIS, CIS Lambda, CIS-E, or CIS Motronic.
Like I said 80mm
And it is not just the plate, it is the plate, cone, and meter.
I went out and measured all I had on hand. Diameter x Depth x Top Cone Diamter, all in inches
5 Cylinder 10V CIS-E 3.15 x 1.8 x 4.52
4 Cylinder 16V 2.0 CIS-Motronic 3.15 x 1.8 x 4.2
4 Cylinder 8/16V 1.8 CIS-E 3.15 x 1.53 x 4.2
4 Cylinder 8V 1.8 (MK1 GTI) 3.13 x 1.6 x 4.45
Both my MK1 GTI's had parts of different models. The one I measured was the Euro GTI meter and Cone and is best suited to your GTI, though all of the above would function mechanically though not electronically.
Thanks for your added input. Interestingly I found that my '80 Caddy "Sport Truck" has the same dimensions as those of the GTI noted above. I don't know if it was replaced at some point or if the Sport Truck got something special; it came with a lot of "GTI'ish" equipment, such as the bumpers, the gauges, the steering wheel, etc. However the throttle body has the smaller insert on the primary side (another area I don't much about the differences between models, years, etc).
Thanks again to "RabbitNotHopper" for the input.
Yes, my Caddy is a early '80 Westy with the EGR (non-Lambda) and restriction in the primary throttle body port.
I did not realize the restriction was there for the EGR's sake, but that makes sense.
What are each of the three throttle bodies you have illustrated from? And can you tell me if there are other differences (apart from the EGR restriction) in port/butterfly diameters, etc.? Thanks.
I am removing the EGR system and was tempted to try and remove that restriction from my throttle body...assuming it can be. Or is it best to look for a different throttle body altogether?
Sorry to resurrect this old thread, but I have a related question.
In the "Volkswagen Water-cooled Front-drive Performance Handbook" by Greg Raven (published in 1986), the author mentioned two CIS airflow sensors with 80mm plates, one with a thick rim and a "67K" decal, and another with a thin rim. The thick rim unit has a steeper air funnel, therefore it causes the plate to rise higher than the thin rim version for a given amount of air flow, leading to a richer fuel/air mixture.
I have a 1980 Audi 4000 (came with a 1.6 liter engine and K-lambda). It had a 60mm air flow sensor, but was upgraded to the 80mm "67K" unit some 26 years ago, and mated to the original fuel distributor. The engine was also upgraded to a 2.0 liter.
So, I am seeking more info about this 67K air flow sensor. What year and model of VW/Audi was it found in as stock equipment, and any other pertinent data. Does anyone have knowledge about this particular unit?
Also, since my 4000 has oxygen sensor, catalytic converter and frequency valve that regulates the fuel/air mixture, my guess is that the air flow sensor funnel profile is less relevant in the actual mixture. What do you think?
Lastly, is the original fuel distributor now a performance bottleneck, given the larger air flow sensor and larger engine? Does it make any sense to change the fuel distributor too, and if so, to what version? Keep in mind that I still need to pass the bi-annual California smog check which tests tailpipe emissions.
Can you read the air fuel mixture in the exhaust? Wideband? If not, I would spend your money getting one. Drive the car for a few weeks to determine if you need one. Many of the stuff in Raven's book is irrelevant or can be done in a better way.
I took a good look at my 4000 tonight and got some part numbers off the air flow sensor and fuel distributor tags.
The "67K" air flow sensor has factory part number 049133353D and Bosch 0438120033. I can't find the factory number in ETKA, and searching either number on the web produced no useful results. Hmm.
The fuel distributor is a Bosch 0438100058 with no factory part number. Searching the Bosch number on the web leads to a Saab application. Wut? I thought I simply bolted the original fuel distributor onto the 67K air flow sensor, but that was 26 years ago, so maybe I remembered wrong. ETKA shows 049133481H as the stock fuel distributor for a 1980 Audi 4000 California model (YH or YK engine), but that number does not cross back to Bosch 0438100058 by info on the web.
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