Afm

[shaun]

There appears to be a problem with alfa v6 air flow meters, does anyone have any light to shead on this? The problem is possibly restricted to the 24v engine with non original air filters. I think the afm is of the heated wire type.

[Stratos]

What sort of problem?

[Jerry B]

If there `s a problem then somebody forgot to tell my engine.
I run a 24V with a K&N filter that goes ok, but if somebody can make it go better I`d be delighted.

[Stratos]

Originally posted by Jerry B
but if somebody can make it go better I`d be delighted.

But the rest of the Sprint competitors won't be ... :rolleyes:

[shaun]

I have yet to have first hand experience of the meter failier but have been following a thread on the technical section of the GTVV6.com forum. Now and again there are some interesting threads but a lot of rubbish most of the time.

From what I gather aftermarket air filter(s) allow dust and/or oil through onto the afm heated wire and cause premature failier. Since there are no, as yet, problems with V6 engines in Stratos replicas this theory may not be valid. Maybe it is more due to the type of engine use. As a bonus I think the 12V V6 uses a flap type meter and is more robust.

[roger001]

Originally posted by shaun
I think the 12V V6 uses a flap type meter and is more robust.

it sure does - but is more resricting to air flow

[David May]

gather aftermarket air filter(s) allow dust and/or oil through onto the afm heated wire and cause premature failier

If my aftermarket air filter was letting dust and oil through into my engine I would be more concerned for my rings than the flowmeter!! They are certainly sensitive to liquids (and must me mounted the right way up so that condensation and blow-back cannot run back onto the element) but are normally capable of burning off very small quantities of oil and dirt (the Bosch type is usually a ceramic substrate, not a bare wire.).

I suspect that any problems are caused by inadequate maintainance - such as not keeping filter elements correctly oiled - most aftermarket types are not simple paper elements that run dry.

A flap-type is in any circumstance a very poor cousin to the modern heated element flow sensor and is guaranteed to reduce airflow by its very design.

Dave May

[chris.richard]

My 24v is a flap type afm. I don't think the164 had a hot wire type, just other alfa V6 motors.

[David May]

I suspect that A-R dropped the flap-sensors when they were forced to stiffer emission regulations - in Italy that was around 1994 but quite possibly much later in the UK. Both mine and Jerry Baileys 24V have hot-wire types.


Dave May

[chris.richard]

Are they a bolt-on substitution, or does it involve ECU changes?

[David May]

I cant imagine for a minute that they can be compatible. At least a remapping and quite likely a ECU (i/o signal levels) change. If what you've got works, I would stick with it.

Dave May

[Stratos]

Or buy a mappable ECU and get rid of it completely.

[CorseChris]

Originally posted by David May
.... If what you've got works, I would stick with it.

Dave May

Wise words!! Couldn't agree more to be honest. There is a good reason motor manufacturers take years to map an engine. That's because it's difficult. Making power is simple, making it driveable under all conditions isn't.

If you change the mechanical spec of the engine then, yes, of course, get a new ECU. But if it's standard, leave it with a standard ECU & sensors would be my humble advice.

[chris.richard]

MAP sensing is not that common any more - early efi systems used it but less now, as flap type AFM's offer some advantages (notably automatic acceleration enrichment due to the momentum of the flap). hot wire type sensors are less common now as the wire tends to get damaged too easily - a mesh is usually fitted to protect it but this results in more back pressure than a flap type AFM so there's no point. hot film type sensors (same concept, but without the flimsy wire) solve this issue.

Don't know the qualifications of the person who posted. Thought I'd paste it here for what it's worth.:)