Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 914 & 914-6 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
BKOMAR's Avatar
 
Join Date: Jul 2001
Location: North Central Kansas
Posts: 233
Garage
Send a message via Yahoo to BKOMAR
Thumbs up Aux Air Reg CONQUERED!!! (long)

I just HAD to pass this on to you guys! I have had a problem with a high idle for quite a while and just have not been able to figure it out. I have stuck my head in the engine bay quite often twisting hoses...tapping on things...looking and listening for vacuum leaks; all to no avail! Well, my wife has been driving this car daily as of late and I was worried that driving it lean would soon damage something. I got home from work early ( I drove the car today) and after multiple stop lights at 2100 RPMS, I decided to "do something about it". I putzed around with this and that and tried the ether thing to check for leaks, and after I woke up, and no leaks were found ANYWHERE my hunt moved elsewhere. The car was nice and warmed up and I pulled off the AAR hose from the air filter box and it was still sucking air loudly. When I put my finger over the end of the hose, besides getting a severe finger hickey, the idle dropped down nicely, if not... too low( in the past I turned in the idle screw in all the way thinking that would help the idle thing). I was sure now that this was the culprit. I got out my meter and checked to see that the wire to the AAR was getting juice and it was. I then hopped on the kids mini bike( it just rained and I washed the 911..didn't want to get it dirty, and my wife took my Golf ) and rode over to the school we own (AKA the Komar boneyard) and looked for an AAR from one of my parts cars. I slapped that one in and after about 10 min., still 2200 RPMs. I trotted inside and logged on and did a search and found info on the AAR and saw what Dave and Brad said about taking it apart. I did try the soaking thing and also hooked it up to a 12 volt source and saw that it started to close, but after 15 min of watching it it didnt close all the way. In the meantime, my wife came out to the garage and hollered "are you OK?" I turned and said, yeah, why? " I was watching you from the kitchen, and you didn't move for like...15 minutes...just standing there with that thing in your hand" Anyway, decided to tear it apart and figure out why it wasn't closing all the way. The big screwdriver and hammer thing works fine and in 10 min had it open and apart. There is an adjusting screw inside that you can fine tune the thing with so I adjusted it to where it was barely open to begin with. Cleaned it all out real good and checked to see that the heating element was working properly. BTW I did check the resistance and did get 13 ohms as was said in the posts in my search. Anyway, I hooked it all up to the 12 volt source and it did close all the way. Back in the car it went, hooked everything back up, and she fired up and idled at ~900! PURRRFECT! My wife thinks that the ether caused some temporary (or permanent) brain damage because I came in and informed everyone that: DAD, is now known as D-JET GURU, and I proceded to do the moon walk and the "SUPERSTAR" Lunge! I must say though that without this board, the car would be nowhere near where it is running wise, and I would not have had a clue what to do in this instance without you guys! Thanks a ton, Brian
__________________
75 914 2.0L
73 914 2.0L X2
73 914 1.7L X3
71 914 1.7L
87 944S
1987 SAAB 900 Turbo
80 Euro 911SC
1980 Yamaha XT500
Old 03-19-2002, 07:12 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
BKOMAR's Avatar
 
Join Date: Jul 2001
Location: North Central Kansas
Posts: 233
Garage
Send a message via Yahoo to BKOMAR
Update: I drove the car to work this AM and I couldn't be happier! Started without a hitch, 34 degrees outside, idled at 1200. I started out and got about 3 miles from home before my first stop and the car idled at ~900. No problems all the way to work...50 miles. The car ran noticably cooler...the gauge usually runs ~1/2 inch from bottom...today was ~1/4 inch. I have had an intermittant "buck" or miss at cuising speed, maybe once every 4-5 min. and it was also noticably less today. It was so nice to come through the checkpoint (I work on a military base) and not have the car racing and have to yell over the hum. I have a renewed appreciation for this car! If anyone is having a similar problem and you can't find any obvious external vacuum leaks, this is the thing to check out... It really isn't that hard to get the thing open if you have a vise, screwdriver and hammer. Once you get it open... it is obvious what needs to be done to clean it out and get it working right. BTW: I went inside last night and took a look at my Probst FI book and read up a bit about the AAR. After looking at the pictures for a bit (I like books with pictures) it dawned on me: Seeing as how the AAR's for the d-jets are no longer available, yet there are tons and tons of jetronic cars out there in the junkyards, and seeing how simple a device this thing is, can't an AAR from some other car work? There are pics of a different kind of AAR in the book that looks even more simple and possibly easier to service. They all run off of 12V and should open at approx. the same time. is this a viable option? Brad, Dave, anyone? Thanks, Brian
__________________
75 914 2.0L
73 914 2.0L X2
73 914 1.7L X3
71 914 1.7L
87 944S
1987 SAAB 900 Turbo
80 Euro 911SC
1980 Yamaha XT500

Last edited by BKOMAR; 03-20-2002 at 05:01 AM..
Old 03-20-2002, 04:52 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
bowlsby's Avatar
 
Join Date: Oct 1999
Location: San Ramon, CA
Posts: 1,182
The 1.8L L-Jet AAR can be made to work, and is available. Mounting it has to be figured out and the unit has a two-pole wiring connection, but ground one side and 12V to the other and it should work fine.
Old 03-20-2002, 07:59 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Administrator
 
Dave at Pelican Parts's Avatar
 
Join Date: Dec 1969
Location: Silly-Con Valley
Posts: 14,061
Garage
Send a message via AIM to Dave at Pelican Parts Send a message via Yahoo to Dave at Pelican Parts
The differences are three-fold. First, there is the electrical plug. That can be dealt with reasonably easily.

The second difference is the mounting. Can be dealt with by using a bit of creative bracketry.

The third difference is in the time vs. air-allowed-through curve. Some will allow more air than others, and they will taper this amount off at different rates. Differences are probably pretty subtle.

So yes, they can be used and should work pretty decently. But not necessarily perfectly.

--DD
__________________
Pelican Parts 914 Tech Support

A few pics of my car: http://www.pelicanparts.com/gallery/Dave_Darling
Old 03-20-2002, 10:19 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
BKOMAR's Avatar
 
Join Date: Jul 2001
Location: North Central Kansas
Posts: 233
Garage
Send a message via Yahoo to BKOMAR
I have to be the devils advocate here, as usual (don't ask my friends *grin*). I would imagine that most AARs are somewhat tunable just like the stock 2.0L one we are talking about. I am convinced that my AAR is "tuned" somewhat harshly...not letting much air through to begin with. I would think that many AAr's from different makes would be usable. My buddy and I are going to the salvage yard next week... I am now on a mission from GOD and I will be looking for AAR guinea pigs to try out and see if they work...which are tunable etc... I will let you guys know what I find out. For all we know...there may be a more viable/ dependable alternative. It seems athough, after going through the archives of this board, that these tend to be, at least in part, the achilles heel of this system. I would kinda like to have a few working alternatives up on the shelf...especially when I have 4 of these cars on the road when my kids are ready for them. I do have to ask also....what is "work perfectly" when it comes to the stock units...and how can I compare the alternative AARs to the stock one. I am thinking...if it idles at 11-1200 and drops to ~900 after 5-10 min...that is acceptable...Any thoughts? Thanks, Brian
__________________
75 914 2.0L
73 914 2.0L X2
73 914 1.7L X3
71 914 1.7L
87 944S
1987 SAAB 900 Turbo
80 Euro 911SC
1980 Yamaha XT500

Last edited by BKOMAR; 03-20-2002 at 10:44 AM..
Old 03-20-2002, 10:41 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
pbanders's Avatar
 
Join Date: Jan 2001
Location: Phoenix, AZ
Posts: 1,113
Garage
Send a message via Yahoo to pbanders
The hunt for an AAR replacement that isn't NLA sounds like a worthy pursuit to me. I think my AAR works right - but who knows, I've never had a different one on my motor. My complaint it that with mild weather, the AAR shuts too quickly. Mine shuts within about 2 or 3 minutes on a typical spring day here in Phoenix, and my car seems like it would run better if this took longer - about 10 minutes. Adjustability would be nice, too.
Old 03-20-2002, 10:51 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
Registered User
 
BKOMAR's Avatar
 
Join Date: Jul 2001
Location: North Central Kansas
Posts: 233
Garage
Send a message via Yahoo to BKOMAR
After getting mine pulled apart and cleaned up... I put 12V to it and watched the valve close. It was not a smooth operation by any means, meaning it would pop( twist) and wait a bit and then Pop again...slowly closing the slot that allowed the air to pass. This operation took a good 10 min to go from 1/2 open (that's where I set it to) to closed completely. The "hole" or slot that allowed the air sure seemed large to me. It seemed larger than leaving a distributor vacuum line open. I even thought about a "manual" AAR, similar to a manual choke on an old bug...everything was so much simpler and straight forward back then *grin*. Anyway...ultimately...the thought is...if I can find a good alternative AAR replacement...it might be cheaper to get from pep boys or autozone or the like in rebuilt or new condition. We'll see....this is actually going to be fun... You know Brad, I used to wonder what your motivation was regarding all this FI stuff, but I actually had fun playing around with this thing last night and I think trying out all that I can find will also be a kick, hopefully it will help us all out! Brian
__________________
75 914 2.0L
73 914 2.0L X2
73 914 1.7L X3
71 914 1.7L
87 944S
1987 SAAB 900 Turbo
80 Euro 911SC
1980 Yamaha XT500
Old 03-20-2002, 11:17 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
Va914's Avatar
 
Join Date: Jul 2000
Location: Williamsburg, VA
Posts: 1,147
Just a thought...
Could you put a Toggle switch on the 12v side and control the AAR. It you break the connection it will not heat up and will stay open? SO, if you want the aar to be on longer, you drive for a few min's and then flick the switch.

Just a thought

Kerry
__________________
Kerry (Back on the road, sort of)

914-6 in the Werks
Old 03-20-2002, 11:36 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered User
 
pbanders's Avatar
 
Join Date: Jan 2001
Location: Phoenix, AZ
Posts: 1,113
Garage
Send a message via Yahoo to pbanders
Toggle switch is a good idea. Cheap and simple.

Brian, watch out. Figuring out how stuff works can develop into an obsession. I'm proof of that
Old 03-20-2002, 12:22 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered User
 
bowlsby's Avatar
 
Join Date: Oct 1999
Location: San Ramon, CA
Posts: 1,182
I've been eying this fast idle component, or something similar, as an AAR replacement:

From the SDS aftermarket FI site:

http://www.sdsefi.com/specific.html

The fast idle option consists of ...a modified relay [uh toggle switch] and an air bypass solenoid. ...the solenoid opens and bypasses additional air past the throttle plate to increase idle speed.... The control system is either on or off. There is no proportional control of rpm. $70US

basically just a solenoid controlled shut-off valve. I would also think something could be easily rigged with a small brass inline plumbing valve as a direct replacement of the factory AAR, it just would be manually operated...
Old 03-20-2002, 01:03 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registered User
 
BKOMAR's Avatar
 
Join Date: Jul 2001
Location: North Central Kansas
Posts: 233
Garage
Send a message via Yahoo to BKOMAR
As a side question....please put my mind at ease, and tell me that the couple of thousand miles that this thing has been stuck open and I have tolerated it has not done damage to my engine. It has obviously been running lean...what does this mean when it comes to burning valves etc... I did just do the valve adjustment and oil change and the valves were all within spec. after ~4000 miles. BOWLSBY: could that thing be hooked up to a temp sensor switch or adjustable electronic timer that would make it all automatic? Then no worry about forgetting to turn on the switch. Brian
__________________
75 914 2.0L
73 914 2.0L X2
73 914 1.7L X3
71 914 1.7L
87 944S
1987 SAAB 900 Turbo
80 Euro 911SC
1980 Yamaha XT500

Last edited by BKOMAR; 03-20-2002 at 01:42 PM..
Old 03-20-2002, 01:40 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered User
 
bowlsby's Avatar
 
Join Date: Oct 1999
Location: San Ramon, CA
Posts: 1,182
Well the cold start valve operates similarly. The CSV has constant voltage to it while the *starter*operates and has an inline ground in the form of the thermo(time) switch. When the engine temp warms above a preset level, *or when the starter is off* the TTS opens the circuit and voila, no more CSV injection.

The AAV on the D-Jet cars is independent of the FI system. It receives its 12v signal, constantly, from the voltage regulator plate as long as the car is running. Basically the AAV is supposed to be always open when the engine is cold (default function, no voltage applied). When the car starts, 12v goes to the heater in the AAV and after a few minutes, the heat created by the heater, or the engine, closes the bimetallic function of the AAV. The heater circuit is always on when the car operates, keeping the valve closed. No wonder those 13 watt heaters burn out after 30 years huh?

So, if a normally closed, solenoid-operated AAV were to be installed and supplied with constant voltage and equipped with an inline thermotime switch in the circuit for the ground path, I think it would work. When the engine reaches operating temp, the TTS opens, opening the circuit (deleting the ground path) and the AAV turns off. Automatically and instantly. Hmmm. Sounds like adding a TTS to the 2 pole 1.8L AAV might have promise after all. Those 1.8L style AAV units were used on many many cars. Check the wrecking yards, they are full of them.

DD busted my chops again. Thanks Dave!

Last edited by bowlsby; 03-20-2002 at 08:51 PM..
Old 03-20-2002, 03:31 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
 
Administrator
 
Dave at Pelican Parts's Avatar
 
Join Date: Dec 1969
Location: Silly-Con Valley
Posts: 14,061
Garage
Send a message via AIM to Dave at Pelican Parts Send a message via Yahoo to Dave at Pelican Parts
A couple of points:

First, the CSV is only supplied current when the starter is cranking. Its power supply is from the yellow wire from the key to the starter. You're quite right about the TTS supplying the ground or disconnecting.

Second, you will not run lean when your AAR is open. It simply lets air past the throttle valve. In an L-jet car (stock 1.8, 912E, etc.) this air has already been measured by the air flow meter, so it is matched with fuel by the FI. In a D-jet car (stock 1.7, 2.0, etc.) the MPS senses the higher manifold pressure from this extra air getting in, and adds enough fuel to match. So the mixture itself is not really affected--just the amount of air (and fuel to match!) that goes in.

So you haven't necessarily been running lean and hurting the motor. Running lean is bad--it leads to ugly things like dropped valve seats. Don't ask how I know...

--DD
__________________
Pelican Parts 914 Tech Support

A few pics of my car: http://www.pelicanparts.com/gallery/Dave_Darling
Old 03-20-2002, 03:41 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Registered User
 
BKOMAR's Avatar
 
Join Date: Jul 2001
Location: North Central Kansas
Posts: 233
Garage
Send a message via Yahoo to BKOMAR
Whew!!! What would I do without you guys!! I will sleep easier tonight! I seriously thought I was hurting the engine....so I really haven't driven it that much with that in mind. I will get back to everyone with what I find at the salvage yard!! Thanks a bunch!!! Brian
__________________
75 914 2.0L
73 914 2.0L X2
73 914 1.7L X3
71 914 1.7L
87 944S
1987 SAAB 900 Turbo
80 Euro 911SC
1980 Yamaha XT500
Old 03-20-2002, 03:52 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Registered User
 
RustyWa's Avatar
 
Join Date: Jul 2001
Location: Kent, Wa
Posts: 372
Garage
What are some things we can do to keep our existing (old) AAR's working well? Lube them?

Without cracking them open of course...
__________________
Eric
'75 914 2.0L - Sold!
Old 03-20-2002, 08:44 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
Registered User
 
Join Date: Apr 2001
Location: Friday Harbor, WA
Posts: 155
Garage
I got tired of the whole AAR issue and just removed the damn thing. I plugged the intake at the air cleaner and the opening on the CSV. I dont mind sitting in the car for 5 mins to warm it up.
Old 03-21-2002, 12:53 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 10:47 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.