Why TWO fuel Pressure Regulators (D-jet)?

[oscar]

It connects to the Auxillary Air Valve (AAV) also known as Air Slide and a couple of other terms.  At idle and during warmup it allows extra air into the engine to help increase revs.  As the engine warms it closes and should shutoff completely.

Although I'm watching the megasquirt thread with interest I don't know much about it, however, I would assume MS controls warm up sequence perhaps, or I think that's what thysonsacclaim said.  So if MS does control warm up, you wont need the AAV or that line and both can be removed and plugged.  Just be aware that if you do remove the AAV you'll have to make your own blanking plate that will hold back the coolant from leaking.  The easiest thing to do would be to leave the AAV there but remove air hoses to and from it but plugging their respective ports in the intake/throttle body.

[thysonsacclaim]

Yeah, MS definitely controls the Cold Air Starting. It will enrich the Fuel mixture to compensate for cold start conditions. However, you need to tune it for this first or it won't know and will try to start it as normal.

Converting to MS eliminates the MPS, AAV and Cold Injector. The TPS can be removed or replaced with a newer POT type.

By the way Oscar, I did find one D-Jet Merc that was converted to MS. Check it out:

http://www.mercdjetmegasquirt.britautorepair.com/

[npk]

Yeah, MS definitely controls the Cold Air Starting. It will enrich the Fuel mixture to compensate for cold start conditions. However, you need to tune it for this first or it won't know and will try to start it as normal.

Very true....MS provides Cold Air or Coolant Starting, giving richer injection in the cold morning....reducing the level as the engine gets hotter

Also good to know that MS has acceleration and deceleration enrichment, after-start enrichment and hot IAT ignition retard.

As said, MS (or Haltech, Motec or any after market ECU)conversion is surely an easier way to keep the car running.

I always ensure that ALL wiring joints are soldered and the Grounding points are well and proper(with a coat of conductive grease).

NPK

[npk]

It connects to the Auxillary Air Valve (AAV) also known as Air Slide and a couple of other terms.  At idle and during warmup it allows extra air into the engine to help increase revs.  As the engine warms it closes and should shutoff completely.

May I know (second photo, next to the damper) why is the hose connect to such low point of the block? Is the AAV at the throttle body or at the block(next to the damper)?


Is the air flowing from the throttle body(1st photo) to the point next to the damper(2nd photo) or reverse direction?

I may need to use this air flow line to run the Toyota Vacuum Valve to compensate RPM drop due to cold start and air-con.

[oscar]

May I know (second photo, next to the damper) why is the hose connect to such low point of the block? Is the AAV at the throttle body or at the block(next to the damper)?

Is the air flowing from the throttle body(1st photo) to the point next to the damper(2nd photo) or reverse direction?

I may need to use this air flow line to run the Toyota Vacuum Valve to compensate RPM drop due to cold start and air-con.

The AAV is at the block under the damper.  So that line circled red goes to the AAV.  It supplies filtered air to it.  Another hose then takes the AAV controlled air to the plenum at "C" in the first picture.

Better still, Carl took a better pic to show both lines involved at the intake end.  (1) goes to AAV.  (2) comes from AAV into plenum chamber where cold start valve is.

BTW, thanks thyson for that d-jet 450sl link. Never seen it before, cheers.

[npk]

Thanks....thanks...thanks

I can use 1(filtered air) to go into my Idle control(manual adjustable to give the idling RPM that I prefer) and also a Toyota (adjustable and controlled by MS) for more air during Cold start and Cranking.

Providing more air during cranking makes the engine easier to ignite