Lancia Beta Forum

How do you go about adjusting the air bypass on the Air Flow Meter of an ie car. I know it needs turning with an allen key, but how do you know if it is right. I thought some sort of exhaust analyser might be needed.

Any ideas?

Thanks

Mine was adjusted by the garage during the emissions test of the MOT, the emissions reading was way out. I showed him where the adjuster was on the air flow meter and he did it then and there; few turns and perfect  :)

Believe it or not it can be done without a gas analyzer - so long as the engine/compression/timing etc is in good order.

You need to remember also that screwing the Allen key in (clockwise) richen's the mixture and unscrewing it (counter clock wise) leans it off.

A tool is also required to make life easier for you, also you will get no where trying to adjust with an ordinary Allen key,
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Basically you set the idle to about 900 to 1000 rpm (i prefer 1000) with the engine hot  - at operating/driving temperature, via the slotted screw on the airflow meter, undo the 14mm lock nut first.
You rev the engine to about 2000-2500rpm, take your foot off and watch the rev-counter - it should come down back to idle without dipping much below, if this is what your engine does don't bother adjusting anything else.

If it does not;-
Start by unscrewing the Allen key until it starts to run rough, three to four full turns should do the trick, you will know by the way the idle speed drops a little and the engine shakes.
Then screw back in half turn at a time (half a turn on the tool is half on the screw) until the engine improves and the rev counter does as i have described earlier.
You want it as lean as possible without the rough idling so take your time and you can adjust the idle a little as you do this to keep it around 1000rpm.
The ultimate test is when you put the head lights on, rev the engine and it does not dip down to 500rpm or cut out.

Its a bit of a black art i know but if you are not up to it get your MOT station to adjust it for you - Auto Data give the mixture settings so they will know what to set it too.

Too be honest Betas on injection don't run that great - certainly not like any other injection car .... but they run/idle a whole lot better than most Peugeot 205 GTI's that i have had to deal with!
Isn't that right Chris - your cars "kangarooing" in traffic i just can't eliminate.

Good luck.
 

Thanks Hutch, I'll give that a go at the weekend. It sounds much the same as setting the mixture on a carb.

Its exactly the same but if you have never done an injection system before you may get the impression your turning a mixture screw and nothing is happening as the results are subtle.
Most people would never have thought screwing the Allen key in would result in a leaner mixture - rather like an later SU carburetor.
Sure you wont have trouble as you get the "gist" so to speak.

I've tried this on my IE and it was difficult to judge

It's much easier if your 'friendly' garage will pop it on their machine and tweak it as you can see the change you are making so set it spot on

Paul