idle enrichment on CIS to EFI conversion

bb · 02-15-2005, 08:37 AM

What are some of the options on this. I am waiting on tony's kit to come in today's mail and was wondering what the different options are. Tony uses the AAR valve on his but I am fabricating my own airbox. should I just plumb the AAR valve into my new airbox?, or should I look into a different setup?

Thanks
Oscar
76'
2.7 Turbo going to EFI

asphaltgambler · 02-15-2005, 08:40 AM

Could you be more specific, maybe a diagram?

beepbeep · 02-15-2005, 08:43 AM

huh? Enrichment? What kind of enrichment? Fuel enrichment? Fuel-enrichment is done in software. Air enrichment? Air-enrichment is usually solved with idle-motor.

bb · 02-15-2005, 08:45 AM

Well, What is the AAR valve used for in the CIS?

beepbeep · 02-15-2005, 08:50 AM

Auxillary Air Regulator? It's not needed anymore if you use idle-motor. Of course, you could replace it with AAR in case your EFI doesn't have output for idle-motor.

Lorenfb · 09:22 AM

"Well, What is the AAR valve used for in the CIS?"

That's only used on the early 911s to raise the idle during cold running.
The WUR (warmup regulator) provides the fuel enrichment on all Porsches
up to the 3.2s. The 911SC with Lambda provides additional enrichment and
emissions control. The later EFI 911 Porsches control the fuel mixture (including
enrichment) via the EFI ECU (Bosch Motronic).

Motronic basically includes: ignition control, fuel injection, idle control,
emissions control, fuel pump control, cam shaft advance, drive-lock (anti-theft)
on late 993s & 996/997.

Note: The WUR affects the fuel distributor's control pressure thereby affecting
the fuel injectors pressure. Later CIS systems (CISe), as used by Mercedes Benz
in the mid to late '80s & early '90s, integrated all fuel control functions (WUR, AAR,
& emissions control) into one unit.

BoxsterGT · 02-15-2005, 09:07 AM

The AAR is retained in Tony's kit to give a fast idle during warm up, so you need to plumb it in. Don't spend extra money on somthing else when the AAR works just fine.
I have done (2) MS installations w/ Tony's pieces & am very happy with them. I have a 76 2.7 that I plan to do next. What a difference in how they run. The surging & uneven running is gone.

bb · 02-15-2005, 07:29 PM

So, where will I make my hole to plumb for it? in the airbox or before the throttle body? I don't know if it matters that it is a turbo.

Thanks

911Mac · 02-15-2005, 09:29 PM

It's got to be below the butterfly on the throttlebody to be effective. FWIW - I didn't think Tony's original kit was intended for Turbos. There are guys running turbos with the version of Megasquirt Tony was using with the kit, but enhanced versions are being worked on that have more bells and whistles. Tony has been working on a turbo version of the kit and would be the one to talk to about any issues or concerns.

-Mac

tbitz · 02-18-2005, 04:36 PM

In my CIS to EFI kit I retain the orginal AAR for cold "idle up" control. The AAR provides bypass air to the engine when it is cold. This keeps the rpms up until the engine warms up. The AAR must be plumbed below the throttle body. The open end of the AAR must also have a small air filter.

MegaSquirt does support a solenoid based idle up regulator, but the orginal Bosch AAR works so there is no point in adding cost for nothing. I tried to keep the cost of the kit down, by reusing as much as possible and not adding any unnecessary 'bling'.

As for the turbo, I believe Oscar is turbocharging his 911SC.

Cheers,

JohnJL · 05-12-2006, 03:47 AM

When planning to reuse the original AAR with Megasquirt 2 v3, what are the correct electrical connections? I have a Bosch 280 140 218 like the CIS primer page describes (http://members.rennlist.com/jimwms/CIS/CIShome.html)

I assume one AAR connection is to ground, is the other to 12v to power the heater element, or to MS2 to send power when temps are low?

thanks

alphie · 05-12-2006, 04:03 AM

As Tony mentions the AAR needs to plumb to the throttle body below the butterfly, i.e. one hose below butterfly to the output of the AAR. The input side of the AAR will require some sort of air filtration. You can attach a small breather filter, or as I and others have done, plumb a line back to the air intake (or back to the throttle body ABOVE the butterfly). Doing that will provide filtered air to the AAR.

Having said that I think I'm going to attach a small breather filter on the input side of the AAR as Tony mentions, just to cut down on the extra plumbing. I think I would prefer a hand throttle but I haven't really found (or looked that closely) at what would be required to do that.

JohnJL · 05-12-2006, 04:30 AM

Thanks Alphie, but my question is with regards to the electrical connections.

alphie · 05-12-2006, 04:52 AM

John, sorry for the confusion. I wasn't tyring to answer your question, I was replying to Oscar's original question about the airbox and AAR.

tbitz · 05-12-2006, 09:06 AM

Quote:

Originally posted by JohnJL
When planning to reuse the original AAR with Megasquirt 2 v3, what are the correct electrical connections? I have a Bosch 280 140 218 like the CIS primer page describes (http://members.rennlist.com/jimwms/CIS/CIShome.html)

I assume one AAR connection is to ground, is the other to 12v to power the heater element, or to MS2 to send power when temps are low?

thanks

No connection from the AAR goes to MegaSquirt. The Bosch AAR runs on its own. It just needs +12v and ground.

JohnJL · 05-12-2006, 02:00 PM

Alphie,
OK, sorry for the confusion. I was ressurecting an old thread with my post.

Tony,
Thanks as always Tony.

John