anyone know how to calibrate one for a 1.8 engine?

When I open my throttle the sweeper does not go all the way?

It may not. That spring is designed to hold against a wide open throttle at high engine RPM under load. It may not go all the way without the load on the engine.


I have the calibration gauge. Unfortunately, the meter that is supposed to work with the gauge is INOP.


If you have altered it, I would suggest that you get a replacement. I would not suggest a rebuilt one, as they are calibrated for a VW type I. The spring and wiper adjustments are different for a Type IV.

When a rebuild meant for a VW is used on a 914, what performance issues arise ?

You can use a wideband O2 sensor to calibrate it, and make sure you are running the right air-fuel ratio. If you need one, let me know.

so you are running the motor at WOT????

depending on the conditions, it might not "need" to open 100%, I don't think it's a 1:1 relationship between the throttle and the AFM door

Use the LM1 meter and adjust the sweeper (loosen that tiny screw) very slightly to set the AFR to 14 to 1 under load driving. Should be stable from idle to WOT otherwise you have some other problem.

Worked great on my bus with Ljet. See pic on other post.

You probably want to run a little lower than 14 for better power, and a little cooler running.

You can try 13.7 to 1 but that seemed too rich in my Westy and 13.9 is one tick away from 14.0.

Try it and see your results....look at your plug color and CHT, oil temps. I run cool CHTs so I can get away with it. I want to test a stock 1.8L and see what the factory set the AFR at. Book says 13.7 for partload for Djet but the AFR goes all over the place compared to Ljet.

pic of inside of the AFM. Loosen the screw after removing the glue. Slight movements mean alot!!! You will have to bend the FP shutoff arm when done so its right too or the FP will run with the engine stopped.

Nice illustration of te AFM adjustment; what is an LM1 ?

Its a wideband O2 sensor Jim.

http://www.innovatemotorsports.com/products/lm1.php

Why would a T4 airbox be calibrated to T1 specs? Different plug, different number of pins, different intake boot diameter, and a different engine with different characteristics. The T1 airbox WON'T FIT on a T4 engine, and vice-versa........ The Cap'n

BTW, IIRC, the 914 airboxes (2 or 3 or more part numbers), have been NLA for years. NOT the same as 2 litre busses.

So what is the difference in the AFM as the part numbers are the same. Later buses AFM's have a suffix lettercode.

Thanks for posting the link. Thats very interesting.

Great tuning tool for $400! I have alot of fun with mine.

If you need one some time, I have one Jim. could bring it to the bbq some time if you wanted to check your car.

Update.
Thanks Chris for bringing your wideband sensor to the bar-b-que and testing my car. Very interesting. I think we eliminated the AFM as the idle problem. Learned alot too.....

Well, tell us what your readings were! Share! share!

Readings were around 14.2-14.5 at idle, and 13.5 at WOT.

man tuning that afm blindly is harder than my rust repair...

A mite lean I'd say

Interestingly it doesn't run hot like it had before installing the rebuilt AFM. I'm still a little confused about the adjusting. I was looking at the picture of the AFM control mech posted previously and I'm unclear about what part you adjust. I was under the impression that the round black toothed doodah was moved; but the picture says to loosen the screw and move the arm---or did I read it wrong. Since I haven't does this before, it's all new.

And thanks for all the info,

ok, check this out on adjusting the AFM arm.

K-

Thanks.