Someone's Drilled A Hole In Afm Flap

[KRISKARRERA 2 1 Cars]

We know about changing the spring tension in an air flow meter but why drill a hole in the flap!?

[All Praise The GTI 3]

as a guess id say to help idle???

but i know nothing...!

[Miles 331 1 Cars]

To make it lighter?

[cybernck 402 1 Cars]

it's a rotten AFM so a worm has eaten through it?

[paul205mi16 4]

I recieved a Mi16 (202) AFM of ebay to sort my ongoing fueling probs last week, and guess what.. It also has a hole drilled in the exact same place (slightly off centre to the middle too)

I put a small screw in the hole and fitted it like that, Fired it up today and seems ok if not a litle lumpy on idle tho..

The AFM was made in 1988 if that makes any difference, But my other one made in 1990 has no hole and niehter has any other that I've seen.

[KRISKARRERA 2 1 Cars]

Ooooh this is getting mysterious now!

2 members so far of this elite club.

[pug_ham 244 3 Cars]

The Mi AFM I have also has that hole in the plate.

 

If you look there is no bypass section in the AFM body like on the 8v so it'll be there to allow air to flow through & assist the icv imo

 

The circle in the picture below is where air flows around the plate on the 8v AFM but the management systems are such a world apart on comlexity (even back then) its probably no comparison.

 

Graham.

[maturin23 10]

Oddly enough I've got an Mi16 (0280202202) AFM sat on my desk that arrived through the post this morning - this DOESN'T have the hole in the flap.

[GLPoomobile 958]

Oddly enough I've got an Mi16 (0280202202) AFM sat on my desk that arrived through the post this morning - this DOESN'T have the hole in the flap.

 

Nor does my knackered AFM. Dunno about the spare one I've borrowed from Dan Taylor, but I'll check in the next few days.

 

(pierced flaps, snigger )

[paul205mi16 4]

I Would like to know the reasons behind this..

[Ryan 99]

Mine has the hole, exactly the same position and everything. It's from an 89 BX if it matters.

[C_W 3 1 Cars]

The Mi AFM I have also has that hole in the plate.

 

If you look there is no bypass section in the AFM body like on the 8v so it'll be there to allow air to flow through & assist the icv imo

 

The circle in the picture below is where air flows around the plate on the 8v AFM but the management systems are such a world apart on comlexity (even back then) its probably no comparison.

 

Graham.

 

The bypass hole in the 8v AFM is to adjust the idle mixture (the allen screw is tapered and either blocks or opens this); on the Mi16 the screw is electronic so no need for the bypass section.

[jackherer 543]

I put a small screw in the hole and fitted it like that

 

If the screw comes loose it will destroy your engine.

[paul205mi16 4]

If the screw comes loose it will destroy your engine.

 

Good point!

 

Still strange to find the hole there though. what do we think the effect of the hole will make then?

[KRISKARRERA 2 1 Cars]

Less deflection of the flap and running leaner I'd say. But when not just tighten the spring, that's what I don't understand.

[paul205mi16 4]

I bought mine from a guy on ebay (boro459) He said it was never tampered with to his knowledge.

 

Kris/Ryan...

 

Have you tryed yours on the car and is it overfueling that you can tell?

I don't think it comes from Bosch like that with the hole.

 

Paul.

[28CRAIG 2]

I recieved a Mi16 (202) AFM of ebay to sort my ongoing fueling probs last week, and guess what.. It also has a hole drilled in the exact same place (slightly off centre to the middle too)

I put a small screw in the hole and fitted it like that, Fired it up today and seems ok if not a litle lumpy on idle tho..

The AFM was made in 1988 if that makes any difference, But my other one made in 1990 has no hole and niehter has any other that I've seen.

 

 

I have a 202 without a hole in it where did you find the year? mine is of my j reg 405 it could be somthing to do with the year they were made

[paul205mi16 4]

Thats what I was thinking too m8. The other one I have is a 1990 as i have said which there is no hole.

BTW..

the date is stamped in a circle at the base/bottom of the AFM, in the cast iron.

Cheers.

[KRISKARRERA 2 1 Cars]

My holey one is an '88 jobbie. My holeless AFM is on car now so I can't see the date.

[gti_al 1]

Mine has a hole. It was from a 90 405, and it looks like it is supposed to be there.

 

It does idle pretty badly though...

[KRISKARRERA 2 1 Cars]

Checked my one without a hole and that's a 1988 version too so that's that theory out the window.