Yes it`s Flat Spots

[Anonymous]

Fitted K&N filter at the normal Filter location, cleaned the air mass thingy, disconnected the battery for 30 mins & have an irritating 5000rpm flat spot.
Ran the car without a filter prior to K & N by using the shoe from a drain pipe adapted to hold the air mass thingy, effectively straight through , ran
like a dream , no flat spots.
The drain pipe setup was  slightly less in diameter than the K & N. setup could the problem be to much air?.
On the odd occasion it will rev throudh the 5000 band and it feels like a different motor.
Sounds terrific on full chat.
Why No flat spot slightly restricted without filter and flate spot with filter?.

Had car 4 Months most enjoyable Born again Ex Biker circa 1944.

[Anonymous]

Try cleaning your MAF,instructions in my signature.

[Wabbitkilla]

Is this a K&N kit, or just slapping a filter on?

[loadswine]

The housing for the MAF needs to be exactly the area and profile as stock, or the metering will be off, possibly enough to cause damage.
Its not a good idea to fabricte a MAF housing unless you can replicate the stock size and profile exactly. If you run some form of aftermarket engine management, then it could be possible to map for it.
I think the housing is at the root of your problem.

[SteveJ]

Try cleaning your MAF,instructions in my signature.

cleaned the air mass thingy, disconnected the battery for 30 mins

  s:roll: :roll: s:roll:  

Is this a K&N kit, or just slapping a filter on?

If I had to take a guess from the rest of the post I would say it's just a filter   s:lol: :lol: s:lol:  

The housing for the MAF needs to be exactly the area and profile as stock, or the metering will be off, possibly enough to cause damage.

Almost certainly running lean in open-loop due to under-reading air-flow. Quite probably lean enough to start cooking things at WOT.

As Nigel says - the profile of the pipework where the MAF was originally mounted is über critical including all of the little vanes. If you want to run a gerry-rigged MAF & intake system you MUST get a piggyback (and get it tuned) at the very least in order to re-map the output curve from the MAF.

[Anonymous]

Fancy the housing solution and will replicate the original area by turning a new one on the lathe. Produced the one thats on to maximise available area from
material stock used thinking more area more flow more performance.Have taken on board the comment about is it just a filter or an expensive kit and must say
its home brewed but totally profesional as far as the engieering and has cost £13. The theory behind what the thingy does is still on my learning curve.
Will post the outcome of my endeavou.rs as soon as its made and tested.
Thank you to all who have taken the time to reply, thus increasing my knowledge of what thingys do.

[SteveJ]

The machining can be as professional as you like, but if you deviate from the exact cross sectional profile (and that means all of the vanes as well not just the area) of the original MAF tube the ECU won't get the correct readings and when you enter the open-loop area of the ECU's map it will run rich or lean. In closed-loop the ECU can compensate using the O2's for feeback. In open-loop it doesn't have the benefit of that feedback so relies on what it was told in the factory.

IMHO you really should look into how modern ECU's & MAF sensors work before trying to develop your own MAF mount.

Do you have a wideband O2 sensor so you can at least see how badly your fuelling is being affected in open-loop? If you don't then be prepared to replace the engine when it finally cries enough is enough.

[mrzwei]

[quote="SteveJ" über [/quote]

Slight drift and apologies for my computer illiteracy but how did you get the Umlaout?

[Anonymous]

Steve.
Understand what you say but i feel that the original bit of the MAF sensor can be incorporated into a re-engineered mount.
Many thanks for your input.
The lengths we may go to just to save a pounds, but the doing of it is part of the challange.
May have to change my name to tight arse!!!!.

[spit]

Its so good to see a passion for tackling challenge with effort. Hope you get a good result.

Slight drift ..... but how did you get the Umlaout?

Dunno how Steve does it, but holding alt and typing in a number gives you access to all sorts of alternative characters.  m http://usefulshortcuts.com/downloads/ALT-Codes.pdf m
[/drift]

[SteveJ]

Its so good to see a passion for tackling challenge with effort. Hope you get a good result.

Slight drift ..... but how did you get the Umlaout?

Dunno how Steve does it, but holding alt and typing in a number gives you access to all sorts of alternative characters.  m http://usefulshortcuts.com/downloads/ALT-Codes.pdf m
[/drift]

Or just use charmap on a Windoze machine   s:) s:)

[Anonymous]

Hi. Just to finish off this post, having taken into account the undoubtedly good replies i have incorporated the vanes onto my creation.
     NO MORE FLAT SPOTS in fact its as smooth as a cashmere cod piece, revs all through range onto the limiter.
    Going SORN now for the winter, but will keep an eye on the site to see what people are up to.
    Nearly forgot to mention, joined the club.
    Thanks to all that have contributed to increasing my knowledge of "Thingys".

[Wabbitkilla]

Good work well done ... And I am relieved it's running ok now for you