low428

I direct this question mainly to Pete (XR9UTE) and please excuse my naivety can you use the ford EEC-IV in conjunction with the downdraught webers style throttle body injection system?

anakha

I reckon I can answer this one. Sure you can. Just need an EEC-IV that was designed for CFI engine like the EA 6packs. I'm Pete can fill in the details.

RAPTOR

CFI engine? You still need 2 injectors for each weber style throttle-bodies, one for each cylinder. Are we talking a 6 or 8 cyl car?

How would the EEC-IV determine airflow (single MAF ) with multiple weber style throttle-bodies? Would they all draw through a single plenum?

Not that I have a clue about this stuff - just casual obsevations.

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anakha

Sorry, brain spasm. I was thinking common plenum. Let me just crawl into back into my cage. :dead:

Jesmol

EEC-IV dont need a MAF do they??, my 6Cyl has a MAP and no MAF?:oo1:

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anakha

They can run either MAF or MAP (US guys call this type speed density).

RAPTOR

MAF, MAP whatever (I hate acronyms)

They both determine the engines air requirements, no?

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EA S

I'll probably end up crawling back to my cage, too, because I'm relying on my geriatric memory, but I think MAP is manifold absolute pressure and measures barometric and manifold air pressure to determine fuel/air ratio for injectors. I think MAF is mass air flow that gives a more accurate measure of the air passing through, but don't know how, and gives a more accurate fuel/air ratio related to the donk's requirements.

I thought MAP was for 6 cyl EFI, both CFI and MPI, and MAF for V8 SEFI.

ebxr8240

You can stay out of you'r cage..Prety well spot on...I.M.O
You wouldn't need a common throttle body with map..
As there is NO senser used.
Maf's work on a hot wire in a air flow.As you know elecricity heats up the conductor where there is a resistance.
The eec measure the volts that passes through it.The more air
the more cooling there is on this wire [like an element] the eec
reads this as volume/ mass..There often is another wire there
to measure ambiant temp as well."Mass air" is what it's often called in the states.. Did I get that right Anakha????
maf=mass air flo / map=speed density[6 cyl & f150v8]

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anakha

You're on the money with the MAF ebxr8240 but at least on the Ford MAP vehicles the air mass entering the engine is inferred by a combination of the MAP, TPS and ACT sensors. Not sure how they do it where multiple throttle bodies are used like on V8 Supercars.

This is why MAP vehicles are more sensitive to engine mods. As the engine's volumetric efficency changes (like heads/cam) the stock programming no longer gets accurate info on the actual air mass entering engine (because it is inferred not directly measured) and thus the car runs worse.

MAF vehicles can run into similar problem if the engine is modified enough to ingest a heap more air. The MAF sensor can only read up to a particular mass of air depending on meter size and when this limit is reached the car will lean out. This is known as 'pegging' the MAF and often happens when the car is super/turbo-charged. In these cases the options are either get a bigger MAF or tweak the MAF to allow reading larger amounts of air.