Re: Some details of the 2AZ-FE engine

Nate Nagel wrote:
> Built_Well wrote:
> > C. E. White wrote:
> >
> >> EdV wrote:
> >>
> >>> Is the 2AZ-FE considered a direct injectin engine?
> >>
> >>No
> >
> > =============
> >
> > The 2AZ-FE is a direct injection engine. It does not
> > use a mechanical distributor, and the engine does
> > use a crankshaft sensor and a camshaft sensor, among
> > other things.
>
> "direct injection" typically refers to a very high pressure fuel
> injection system that injects fuel directly into the combustion chamber
> rather than into the intake runner or a throttle body.
>
> What you are describing is a "distributorless ignition."
>
> nate
============================================

Very good information. I enjoyed reading it, and you're
right that the Camry does not inject fuel into the combustion
chamber but into the "antechamber" in the cylinder head that
comes just before the valve. That's what the manual's diagram
seems to show anyway.

But the 2AZ-FE /is/ a Direct Injection System. Here's a quote
from the Camry's service and repair manual on Page EG-57:

"A DIS (Direct Ignition System) has been adopted. The DIS improves
the ignition timing accuracy, reduces high-voltage loss, and
enhances the overall reliability of the ignition system by
eliminating the distributor. The DIS in this engine is an
independent ignition system which has one ignition coil (with
igniter) for each cylinder."

Also, the book "Auto Upkeep" says, "Some manufacturers call the
distributor-less ignition system a direct ignition system."

Maybe there are two sides with an honest difference of opinion?
Sorta like how API Group III oils are considered synthetic in
the U.S.A., but not in Europe.

However, the book says there are 3 types of ignition systems:

Conventional, Electronic, and Distributor-less.

The web site ProCarCare.com doesn't mention firing into the
combustion chamber as a pre-requisite for D.I.S.

Here's a quote:

The Direct Ignition System (DIS) uses either a magnetic crankshaft
sensor, camshaft position sensor, or both, to determine crankshaft
position and engine speed. This signal is sent to the ignition
control module or engine control module which then energizes the
appropriate coil.

You obviously know a whole lot more about cars than I do, but the
2AZ-FE does seem to be a Direct Ignition System.

Here's a link to the ProCarCare site with the info:

http://www.procarcare.com/icarumba/resourcecenter/encyclopedia/icar_resourcecenter_encyclopedia_ignition.asp

Britannica Online seems to agree:

direct-ignition system, or distributor-less ignition system
(engineering):

description and use:

Many automobile engines now use a distributor-less ignition
system, or direct-ignition system, in which a high-voltage pulse
is directly applied to coils that sit on top of the spark plugs
(known as coil-on-plug). The major components of these systems
are a coil pack, an ignition module, a crankshaft reluctor ring,
a magnetic sensor, and an electronic control module.

>From Wikipedia's entry on Ignition System:

Other systems dispense with the distributor and coil and use
special spark plugs which each contain their own coil
(Direct Ignition). This means high voltages are not routed all
over the engine, but are instead created at the point at which
they are needed. Such designs offer potentially much greater
reliability than conventional arrangements.

A site devoted to the Honda Insight says this:

The Insight engine employs a direct ignition system similar to
those used on the Honda S2000 and the 1999 Odyssey. Separate
ignition coils for each cylinder are located directly above
the spark plugs.

On Jul 16, 2:34 am, Built_Well <[email protected]> wrote:
> Nate Nagel wrote:
> > Built_Well wrote:
> > > C. E. White wrote:
>
> > >>  EdV wrote:
>
> > >>> Is the 2AZ-FE considered a direct injectin engine?
>
> > >>No
>
> > > =============
>
> > > The 2AZ-FE is a direct injection engine.  It does not
> > > use a mechanical distributor, and the engine does
> > > use a crankshaft sensor and a camshaft sensor, among
> > > other things.
>
> > "direct injection" typically refers to a very high pressure fuel
> > injection system that injects fuel directly into the combustion chamber
> > rather than into the intake runner or a throttle body.
>
> > What you are describing is a "distributorless ignition."
>
> > nate
>
> ============================================
>
> Very good information.  I enjoyed reading it, and you're
> right that the Camry does not inject fuel into the combustion
> chamber but into the "antechamber" in the cylinder head that
> comes just before the valve.  That's what the manual's diagram
> seems to show anyway.
>
> But the 2AZ-FE /is/ a Direct Injection System.  Here's a quote
> from the Camry's service and repair manual on Page EG-57:
>
> "A DIS (Direct Ignition System) has been adopted. The DIS improves
> the ignition timing accuracy, reduces high-voltage loss, and
> enhances the overall reliability of the ignition system by
> eliminating the distributor.  The DIS in this engine is an
> independent ignition system which has one ignition coil (with
> igniter) for each cylinder."
>
> Also, the book "Auto Upkeep" says, "Some manufacturers call the
> distributor-less ignition system a direct ignition system."
>
> Maybe there are two sides with an honest difference of opinion?
> Sorta like how API Group III oils are considered synthetic in
> the U.S.A., but not in Europe.
>
> However, the book says there are 3 types of ignition systems:
>
> Conventional, Electronic, and Distributor-less.
>
> The web site ProCarCare.com doesn't mention firing into the
> combustion chamber as a pre-requisite for D.I.S.
>
> Here's a quote:
>
> The Direct Ignition System (DIS) uses either a magnetic crankshaft
> sensor, camshaft position sensor, or both, to determine crankshaft
> position and engine speed.  This signal is sent to the ignition
> control module or engine control module which then energizes the
> appropriate coil.
>
> You obviously know a whole lot more about cars than I do, but the
> 2AZ-FE does seem to be a Direct Ignition System.
>
> Here's a link to the ProCarCare site with the info:
>
> http://www.procarcare.com/icarumba/resourcecenter/encyclopedia/icar_r...
>
> Britannica Online seems to agree:
>
> direct-ignition system, or distributor-less ignition system
> (engineering):
>
>   description and use:
>
>   Many automobile engines now use a distributor-less ignition
> system, or direct-ignition system, in which a high-voltage pulse
> is directly applied to coils that sit on top of the spark plugs
> (known as coil-on-plug). The major components of these systems
> are a coil pack, an ignition module, a crankshaft reluctor ring,
> a magnetic sensor, and an electronic control module.
>
> From Wikipedia's entry on Ignition System:
>
> Other systems dispense with the distributor and coil and use
> special spark plugs which each contain their own coil
> (Direct Ignition). This means high voltages are not routed all
> over the engine, but are instead created at the point at which
> they are needed. Such designs offer potentially much greater
> reliability than conventional arrangements.
>
> A site devoted to the Honda Insight says this:
>
> The Insight engine employs a direct ignition system similar to
> those used on the Honda S2000 and the 1999 Odyssey. Separate
> ignition coils for each cylinder are located directly above
> the spark plugs.- Hide quoted text -
>
> - Show quoted text -

Your original post said "direct INJECTION" not "direct IGNITION."
I've never heard of a distributorless ignition called a "direct
ignition" although I guess it kind of makes sense for a coil-on-plug
type setup. Now direct INJECTION refers to something completely
different, as I described in my post. Generally used on Diesel
engines although I have heard that some mfgrs. have or will introduce
it on gas engines as well.

nate