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Ok
FV valve is Andial and it provides extra fuel at boost and it is working properly.
I can watch the afr's drop with each turn of the hobbs dial. So I can eliminate that from the cold start lean problem.
Something the car does not do anymore..
When I used to start it it would high idle then drop down after a few seconds.
Is that controlled by the TTS or CSV?
If not, what?

Old 09-28-2016, 07:15 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #61 (permalink)
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the AAR makes it idle high when cold.
the TTS and CSV work together to provide a shot of fuel when starting cold. once the key is released it no longer has a function.

just to be clear. the FV will vibrate with the key on, engine off and cold?

how is your timing?
the vacuum advance should go thru a thermo time valve (TTV) on the back on the engine block.
you can bypass it and run the vac directly to the throttle body (TB).
with the vac removed from the dist check the mechanical advance with a timing light.
another test is with it warm and idling, remove the vac hose in the inside of the dist vac port. (retard). idle should go up. then connect it to the outside port. (vac advance). idle should go up even more. (verify there is vac on the retard hose at idle).

you said it runs bad below 3k.
this is where the speed relay switches from closed loop to open loop.
closed loop the O2 sensor (if you had one) would be used and the mixture is controlled by the FV. in open loop the system puts the FV in a default mode.
it could be that your mixture is just too lean below 3K.
__________________
86 930 42kmiles [__] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD
88 BMW 325is 200K+ SOLD
05 BMW 330CI 130K:: [__] RUNNING: [__] NOT RUNNING:
08 VOLVO V70 190K:: [__] RUNNING: [__] NOT RUNNING:
90 B2200[__] RUNNING:[] NOT RUNNING:__2000 MER E320 WAGON [] WRECKED:[]RUNNING:
Old 09-28-2016, 10:37 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #62 (permalink)
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Ok the AAR is the auxiliary air valve?
The FV ony comes on at boost, if I turn it on inside the car...Andial.
I a not sure if a 86 turbo came with a FV. It does not vibrate at all.
It gets its signal from the overboost switch on the intercooler and sends fuel only when on boost.
Been like that for at least the last 15 yrs. P/O
Way back when I did check and switch the vac lines as you said and the idle went up...twice.
I will recheck today.
I never checked timing.
Just to be clear...after adjusting the mixture (adding more fuel) it is better.
I only have to wait about a minute or two before she is good to go.
but looking at the afr when starting and popping..she is still way to lean 15-18 if I touch the accelerator.
If I don't touch anything..after starting idle drops for about 5 sec 400-600 rpm and ..15-16 afr then is slowly creeps down to 12-12.5 after a few minutes and runs well. 1000-1050 rpm
For someone who didn't know the car they would say it runs good but for me know what she is capable of and I want it back
Marco ..thanks for hangin in there with me
Mark
Old 09-29-2016, 06:25 AM
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The frequency valve will only vibrate with the key on if the sensor plate is unplugged. Otherwise, the engine has to be running for the frequency valve to operate. Also, unplugging the sensor plate will bring the fuel pumps to life with key-on power.

Personally, I'm still stuck on the fueling. I say just keep adding fuel until the problem is gone. You've already added fuel and found that it improves the situation, so go a little further until the car stops responding or you start making backward progress. Turbos like to run a little fat and based on your numbers it appears you have plenty of wiggle room before you hit Pig Rich.
Old 09-29-2016, 08:14 AM
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I don't think the AFM sw controls the FV. it provides a ground to the yellow relay but there is a "tag" on my diagram that shows the ground going to another page but I cant read where it goes. I doubt it has anything to do with the FV since it leaves the page.
also, looks like the FV and the O2 sensor both get their power from the O2 relay. the other line from the FV goes to the O2 sensor control unit. I would assume it provides a pulsed ground to control the FV.

the 86 FD has to have the FV to operate as far as I know unless it has been modified to run with out it.


your car is like mine. I notice a few things with it but no one else does. in fact, a Porsche mech friend drove it and said it was the best driving 930 he ever drove. he also gives me a hard time because I say it is not "perfect".
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86 930 42kmiles [__] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD
88 BMW 325is 200K+ SOLD
05 BMW 330CI 130K:: [__] RUNNING: [__] NOT RUNNING:
08 VOLVO V70 190K:: [__] RUNNING: [__] NOT RUNNING:
90 B2200[__] RUNNING:[] NOT RUNNING:__2000 MER E320 WAGON [] WRECKED:[]RUNNING:
Old 09-29-2016, 10:00 AM
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call larry at flow control and talk to him. his is a great guy and very knowledgeable. wait til late in the day.
I just don't know enough about the andial system.
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86 930 42kmiles [__] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD
88 BMW 325is 200K+ SOLD
05 BMW 330CI 130K:: [__] RUNNING: [__] NOT RUNNING:
08 VOLVO V70 190K:: [__] RUNNING: [__] NOT RUNNING:
90 B2200[__] RUNNING:[] NOT RUNNING:__2000 MER E320 WAGON [] WRECKED:[]RUNNING:
Old 09-29-2016, 10:02 AM
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I will call Larry...Thank you
I did add more fuel and its idling at 10.8 AFR
Still does it
Would a bad injector cause this?
Old 09-30-2016, 08:19 AM
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Talked to Larry
He said take a hard look at the frequency valve and relay/.
Marco , I have been looking but where is the relay for the FV in a 86 930?
Thanks
Old 09-30-2016, 09:01 AM
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its under the drivers seat.
it is the O2 relay. it looks like the O2 relay provides power to both the O2 sensor and the FV.
its possible it could be the speed relay.
I don't know what the andial system has replaced under the seat.
I know it has solder joint issues. you could remove it and hit all the joints with an iron.

here is what I know about the FV.
if it does not work or is off, the mixture will be extremely lean.
the FV controls the fuel pressure on the lower chambers of the FD by regulating the fuel returning to the tank from the FD. when off, it has max pressure on the lower chamber, this puts max pressure against the springs on the upper side and close the valves that let the fuel goto the injectors thus leaning out the mixture.
when wide open it does the opposite. less pressure against the springs thus the valve opens more easily making it run richer.
the FV is pulsed on and off to control this lower chamber pressure to control the mixture.
it either uses a default pulsing for RPM's above 3k or if the O2 sensor is unplugged, and when cold. this is open loop mode.
when warm and below 3k it uses the O2 sensor to control the FV to control the mixture.
this range of control is very narrow so the WUR has to be set to factory specs and the mixture has to be adjusted for spec for it to maintain the proper mixture.

I am sure larry told you that unless your FD has been modified to run without the FV it will run too lean if it is not working.

if I am wrong I am open to corrections since I have not actually worked on the 930 with a FV. mine has been removed.
__________________
86 930 42kmiles [__] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD
88 BMW 325is 200K+ SOLD
05 BMW 330CI 130K:: [__] RUNNING: [__] NOT RUNNING:
08 VOLVO V70 190K:: [__] RUNNING: [__] NOT RUNNING:
90 B2200[__] RUNNING:[] NOT RUNNING:__2000 MER E320 WAGON [] WRECKED:[]RUNNING:

Last edited by T77911S; 09-30-2016 at 10:34 AM..
Old 09-30-2016, 10:31 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #69 (permalink)
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As I am working thru this car one item at a time I really appreciate your patience and thank you for sharing your knowledge.
That being said .
I can't find the Fudging FV.
It must have been removed by the PO. There is really only one place it can be...Right?
Maybe they did the whole fuel head rebuild when they added the Andial system or
as I look thru my service manual I can't find a FV on a 86 turbo.
Anybody have a Pic?
Thanks
Old 10-01-2016, 07:56 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #70 (permalink)
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OK
S*** has hit the fan.
AFR's all over the place. Car stalls....

For instance,
Cold start AFR's start at 15.5 then work down to 12.5 in about a minute then car goes way lean all the way until it stalls. About a 2 min event.
I can keep it running with the pedal.
Last week the AAR was acting up with that high idle deal after warm up.
I pinched the line and it came down.
Rebuild is probably mandatory.
I might as well go Adj.WUR while I'm at it.
Any other ideas?
Old 10-05-2016, 10:33 AM
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I thought I would have a final post to put this issue to bed.
I pulled the WUR, sent it to RarelyL8, reinstalled it. Works perfectly.
Here's the thing.
As I was taking the pressure readings, they were spot on, by the book.
And it actually took a major breakdown of the WUR to diagnose the problem correctly.
So, in the early stages of WUR failure, you can get low rpm popping, no idle control and afr's all the way to lean then stalling, with all of the fuel pressure readings exactly where they should be.
Hope this helps somebody out there.
Mark
Old 12-04-2016, 07:03 AM
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To see the issues described the pressures must be observed real-time. I have an AFR and fuel pressure gage in the cockpit and use them to test WURs. During the events you describe you will see small changes in warm fuel pressure combined with large swings in AFR. Great to put this issue behind you!

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Old 12-04-2016, 07:23 AM
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