okay, received the 090 WUR, measured it at 25,3 ohms, just like the seller promised,
installed it, and got a start off the key, without touching the accelerator. It idles low still, around 600rpm, but at least it idles on its own, and it will accept throttle immediately without coughing or backfiring...so there's an improvement definately.

Now i have to drive it for around 20 minutes, and reset the mixture and idle speed, and see what those changes will do for the next cold start.

Good to hear......
 

Jan,

Take a baseline data for this new WUR-090 either with the engine running or just the FP. Measure the cold control fuel pressure @ start, 30 sec.,60 sec...........up until the control fuel pressure stabilizes to warm control fuel pressure (max. 5 mins. run). Keep us posted.

Tony

okay, i will do that one of these days,

i went out today for a proper drive, and the difference is very noticeable...turn key, start engine, drive off, without hesitation, without waiting for the motor to catch its breath so to speak, so this already gives a lot of pleasure in day-to-day driving/stopping/starting.
Now i don't have to explain all these starting procedures to my gf anymore...just turn key and go! :)

i didn't have to alter the mixture settings at all when warm.

Post your pressures as follows -this will help a lot of folks-

Ambient temp /CCP/RPM


Most people forget to post ambient temp when posting pressure. The ambient is important when verifiying CCP.

okay, it's about 15°C here

i measured fuel pressures again, this time with the correct 090 WUR with good resistance:

system pressure: 68psi, 4,65bar
cold control: 25psi, 1,6bar
first it rises slowly:
2 min: 30psi, 2 bar
3 min: 35psi, 2,4bar
then it goes quicker:
3m30: 40psi, 2,8bar
4m: 50psi, 3,45bar
4m30: 55 psi, 3,8 bar
it stays on 55 psi then.

i guess that doesn't look too bad.

No that looks normal.

Does a 090 have vac control or not?

nope, no vac control, just a vent i suppose, same as 072.

I see that the CIS primer calls for 1.6 at 10 degrees. But I do not have the graph.

1.6 is probably in the middle of theb band so with 1.6 at 15 degrees you are likely at the rich side of start-up band but if it works I would not bother resetting it.

outside is 11°C now, i'm at 1.45 bar cold control this morning
the graph specifically for my car is here:

http://forums.pelicanparts.com/uploa...1449098242.jpg

Yup. at the rich side of the graph but within the bracket....

Good to go. The start-up should go very well.

What RPMs do you get at idle the first minute at these temps?

Cold idle is still not good. The car runs only with a bit of throttle for the first 30 seconds or so. The car runs good though, no spluttering, good reaction to throttle input...so mixture seems good, just no elevated idle.

ok guys, some more interesting info:

i've installed SSI's and took the opportunity to mount a wideband innovate 02 sensor + controller + gauge. I use the analog output of the wideband controller the emulate a narrowband 02 signal for the lambda brain. Great piece of kit, nice to know the engine is running safe AFR's. The O2 signal works, i see the AFR's react to the input.

cold start i see around 11 AFR when the 02 sensor kicks in (half a minute or so), and i see it rise steadly towards 14.7 after couple of minutes.

Warm:

I set the mixture (without 02 input) at 14.2 AFR, which is around 0,6% CO, according to spec. When i plug in the 02 signal, the car responds nicely and dithers around 14.7.

Cruising, i get 14.7.

I noticed a somewhat flat bottom power (<3000rpm) so i pulled a little trick: i reprogrammed the analog output to 14.2 AFR (laptop programming in a 1981 SC :) ) , and so now i cruise around 14.2 AFR, and throttle response at low rpm's is greatly improved. I also notice much easier getting away at the lights, stalling is almost impossible. I know this doesn't give me more power, but throttle response is worth something too.

Then i noticed something else: when suddenly flooring the throttle, i see no immediate enrichening of the mixture. I go towards 4K, 5K, 6K and the AFR stays at 14.5ish. Only when i let off the throttle or when i punch in the clutch, i see immediate drops to 11 AFR for a split second before the mixture normalises back to it's default dithering.
I also feel a flattening torque after 3500 RPM, i'm sure there should be more power there.
I checked the 15°C temp sensor last year, OK, and i checked the throttle WOT switch (i have 000 resistance from the WOT switch wire to the temp sensor to ground when i go WOT).
Maybe somehow the ground through the temp sensor is not there? Can i ground that wire separately to test?
I'm sure i should see AFR's drop at least from 3K rpm onwards?

thanks for your input,
Jan

idle around 500rpm at cold start.

okay, some more testing, engine warm (20+ minutes of driving):

i'm cruising at 14.2. Floor the throttle, AFR immediately goes to 15.0 and basically stays there untill i let off the throttle or clutch in. 3rd gear, uphill, so at least 5 seconds full throttle...no enrichment...also i think i should have more power up top.
the only time i see lower AFR's is the moment i clutch in, then i see a split second 11's or 12's before returning to normal.

I connected the WOT switch to ground, AFR instantly goes to 13.5 at idle, indicating a higher duty cycle in open loop, so it seems to be working. But the moment i floor it, AFR goes to 15 again and stays there...

I tried running without 02 sensor, but then it's running even leaner.

Pulled the OXS relay, idle drops instantly, push in relay, idle perfect. So there's power to the OXS box.

Basically, everything works very nicely in closed loop...once in open loop, i'm running not rich enough. Is this normal behaviour? i would think not.

Could it be air flow meter related? Last time i took off the boot, it seemed to be sitting correctly.

ok, more testing.

i did a very dirty trick: i disconnected the WOT switch, and set the closed loop at around 13.2 AFR. So now, the FV always tries to get to 13.2 AFR in all conditions.
well, the results are simply awesome: the car pulls straight from 2000 to redline, AFR's stay healthy, and no torque loss in upper regions. It's a canonball...this is what i expected from this engine with the SSI's. Good idle too. This is how the car should feel in open loop.
( I know i lose mpg this way, but i think i can get around that by using the WOT switch to switch between output 1 and output 2 of the wideband controller. output 1 = cruise mode, output 2 = WOT mode)

But of course i would like to get the original system running correctly.

I know now that something is wrong in open loop. The 65% FV pulsing in open loop is for some reason not enough to give the engine enough fuel at WOT.
I think i can exclude fuel pump and fuel distributor, as they can give plenty of fuel during my dirty test.
Maybe the lambda brain has a fault in open loop?

thanks for your insights,
Jan

I am hoping someone who know US systems is going to step in.

Actually what you have done is created the conditions of a 089 WUR with vacuum enrichment at WOT

But why the FV does not do the same thing is beyond me.

Following with intrest.

yep, somehow, the combination of 65 FV pulse, and WOT behaviour (butterfly open, air flow meter opening up) is not giving correct mixture.

Jan,

Would you be so kind as to review what changes were made to improve what condition? As I recall the initial condition was a hard to start, stumbling 81 SC with US CIS.

After reading the thread (engine rebuild aside) it seems that the FV relay, correct WUR, new plugs, and tuning AF mixture/idle w/4 cycle duty meter ultimately improved running condition.

I see above you are going beyond "fixing" by using more fancy tuning. That's cool, but just want to understand more definitively what improved how your car runs.


Sent from my iPhone using Tapatalk

Well, yes and no. I did the things you described yes, and that improved running. Bur along the way something else broke and now i have no wot enrichment, which means no power unless i trick the system with the o2 sensor output.
I think lambda enrichment box is fried, but no way to tell. No info on that thing anywhere.
I am considering bitzracing efi now, because i am fed up with buying expensive secondhand cis parts that dont solve the issues. I dont care for originality, i just drive the car. A well tuned efi should be great for longevity of the engine as well as trouble free starting, good mpg, good power.

Appreciate your final analysis. Many who go through CIS issues, me included, consider the EFI alternative.


Sent from my iPhone using Tapatalk

AAR operation.......
 

Jan,

Have you inspected and confirmed that the AAR (auxiliary air regulator) is open during a cold start? Do a visual inspection of the AAR's slide valve when the engine is cold. Keep us posted. Thanks.

Tony

Hi tony, yes i have, functions perfectly. I'm thinking something has gone wrong with lambda box or lambda enrichment box. I will keep updating this thread untill i find a good solution. I dont think it will be cis though...

And for anyone interested: i tried running the 'trick' that the innovate guy posted here so many years ago: use the wot switch to power a set of relays which switch between output 1 and output 2 from the innovate wideband box. So you could run 14.2 afr at idle and cruising, and lers say 12.8 during wot...but somehow the system senses when the inputs change and i get weird results during dynamic tests...

More so, on the whole internet, i have not found one person who managed to pull this trick off, or at least when they did, post some results afterwards.

But theoretically it is a nice idea....i think the lamda box and enrichment box do more things than we know. They have some intermediate settings, when you go from one state (cruise) to another (wot), and god knows what happens to the o2 input at those times.

...and although this is all very interesting, it is not future proof nor economically sound anymore, thats why i am considering biting the bullet and go full efi, with or without ignition control.

That's why I have these spare ECU's.........
 

Jan,

I know nothing about ECU for th SC's and currently doing some experimentation using an oscilloscope to understand a good ECU from a bad one.

http://forums.pelicanparts.com/uploa...1484666877.jpg

These ECU's were tested and confirmed to be in good working condition (?). And saved them as my control. This is as far my knowledge with ECU starts and ends.

Tony

ok, the first upgrade in my quest to have a properly reliable car in all weathers is the Classic Retrofit CDI+ box. I chose it because of the ease of install, the programmability at a later stage (locking the distributor) and the stock looks. It's pricey, sure, but i don't really care. It has double spark across the revband.

It's basically a plug and play replacement for the Bosch CDI. Just a little twist of the dizzy and all is well.
I went from 5° - 26° advance to 5° - 28° so already some difference in high rpm ignition.

Straight away, i notice more stable low rpm manners. It's easier to get away from the lights, less prone to stall. Low rpm power was already up with the SSI's, but i sense even more now. This is becoming a proper quick and fun car, even if you don't go above 4000 RPM.

I notice little bit leaner numbers on the wideband display, so better burning for sure.

Just went out in the cold, and did a 3-hour-cooldown-0°C semi-cold start, and it fired up on the key, without touching the throttle, that's new to me. Anxious to see what a proper cold start will do tomorrow morning.

A fun bonus is the sweeping tach when you start the car...that's 2010 feel in a 1981 car :)

I've ordered the bitzracing FI kit as well. This will arrive shortly. I chose it once again for easy of install, stock looks, and easy tuning. And it's relativily cheap. I don't need all the modern accessories that come with the more expensive and modern FI upgrades. This is perfect for amateur wrencher like me. It will get rid of the all the aeging CIS components apart from the AAR (cold start air thingie).

Appreciate the update. Sounds like a very reasonable option if CIS becomes difficult to manage.

Know that I will gladly take this aging CIS stuff off your hands ;o)

A little bit delayed because i totalled my daily car, and had to use my 911 as daily driver the last month and a half (what a terrible punishment!),
but,
i've started installing the Tbitz kit 3 days ago, and i'm happy to say i'm all finished, the car is running, no fires, no meltdowns, no black clouds. :)
The box that contains the old stuff is big and heavy: Fuel distributor, Fuel accumulator, Frequency valve, decel valve, AAV, the little enrichment microswitch, throttle switch, the lambda box, the lambda enrichment relay, all the injectors with their metal lines, the aluminium spaghetti trombone vacuum line, the heater blower, and last but not least, the fecking WUR, ALL GONE. Hallelujah.

So, i've got it working together with the classic retrofit CDI+, and this is important to mention: the MS software from the tbitz kit reads the tachsignal to provide fuel. This tach signal is provided by the CDI+ box. Well, the CDI+ box does a tacho sweep when you turn the car on, very cool, BUT, the MS box is already alive at that point, and reads this signal as if the car is already running, and thus dumping ****loads of fuel in the engine, almost hydrolocking it after a couple of attempted starts. That's basically the only issue i've come across after my install.
Reprogrammed the CDI+ to get rid of the tacho sweep and all is well.

I'm combining the whole setup with the innovate LC2 wideband sensor, and everything is now nicely working together. You have to be quite clean in your install: good grounds, clean wiring, all very important.

Now i'm starting the car, letting it warm up (it still uses the AAR), and once warm, click 'autotune' and drive! The car tunes itself to a preset AFR table. I'm sure i'm already up 10MPG, and all the power from my 'cheaty-13-AFR-CIS-workaround' is there. It's fast. And it's only the first day of testing, so i'm basically just starting to alter Tony's base map.
I already feel alot crisper throttle respons too.

Tunerstudio is great, programming on the fly, lots of parameters to learn, but that also means lots of ways to get the engine starting and running perfectly in all conditions.

Big thanks to Tony Bitz and Jonny from Classic Retrofit for their great products and great support.
I'll update whenever i have more information.

cheers, Jan

well, here is an update for you...insert huge swearword...after 1,5 years troubleshooting (okay, and also lots of fun with a fantastic car) i finally found the culprit of my low cold idle...

The frickin' CSV mounting flange is CLOSED. There is NO HOLE. Some PO or mechanic mounted the wrong flange probably because he had too many airleaks, or maybe because he was always driving in 100°F temps...who knows.
The reason i ddin't see this before is because:
- it is almost impossible to remove and check with original CIS in place
- whenever i took off the AAR hoses, i noticed small changes in engine behaviour, so i wrongly assumed the flange was open.

Now, with my removed AC unit, removed heater blower, and bitzracing kit, there is a lot of space and i finally got the balls to take it off and check it. The reason for this check was that i could not get a raised cold idle, even with bitzracing kit with full control of fueling and CDI+ with full control of ignition. No matter what i did, idle was 500 RPM cold...or worse.

so...i took out my drill, and drilled a hole in the csv mounting flange, not a very big one, maybe 8mm diameter (it is a fragile platic little thingie and i didn't want to break it), so i've got less air flowing through.
I also bought a brand new Nissan 300ZX AAR (50 bucks), which does exactly the same as the Porsche one, except that the ports are smaller (3/8" instead of 1/2") and it takes around 10 minutes to fully close. But it does FULLY close. The old Porsche AAR looks like it fully closes, but even when you can't see through it, you could still blow air through it. I'm betting the majority of these old AAR's are like this.
Yes, the bitz kit still uses the AAR, it's the only stock component that's left over.

So now, my cold start went up from 500 to 1000RPM.
Now i can fine tune it with the warm up tuning from the megasquirt.

Hallelujah.
hope this helps anybody out there...i've only seen one other guy on the forums with the exact same problem.

I'm trying to understand the CSV part of this. So did the PO simply cap the entire place where the CSV usually sits?

I borrowed a picture I found. But are you saying that this entire piece was blocked off, meaning there was no injector there?'

http://forums.pelicanparts.com/uploa...1492023802.jpg

hiya,

no, everything was there: csv, aav, decel valve, aar, etc...including all the piping.

The only difference was the dark red part you see on the picture. That part (mounting flange) has an air port to which you attach all the mentioned components. On earlier CIS systems, that part is blocked offinternally because they had a fast idle lever and no need for AAR etc... On my car, it should have been open. (updated part) So the PO mounted the wrong part. It looks exactly the same from the outside.

here's a pic if you can see it:
https://scontent-amt2-1.xx.fbcdn.net/v/t31.0-8/17880159_10155244957682863_3508662787624301961_o.j pg?oh=ea7d919297d5cdf0ab356d8543358cb2&oe=5954F42B

i simply drilled a hole in there now, and it works.

and this is the new AAR,
it looks exactly the same, but actually is 3/4 the size of the original AAR.

(okay, link does not work to competitor of pelican, i understand)
/ac366-intermotor-idle-air-control-valve-mpn-ac366

Sounds like everthing is playing together nicely for you now. Glad to be of assistance!

Any chance of posting some pictures?

let's see if this works...

cabin with wideband and volt gauge:
https://scontent-amt2-1.xx.fbcdn.net...85&oe=598A0885

junk!
https://scontent-amt2-1.xx.fbcdn.net...e4&oe=5954686F

finished engine compartment,

Classic Retrofit CDI+ on the left side, next to the fuel filter. Notice the absence of the fuel accumulator :)

https://scontent-amt2-1.xx.fbcdn.net...74&oe=59958128

my daily 1988 BMW 325i touring (300.000 miles and going very strong), and my former daily 1981 911 SC :) . Just booked an appointment with the bodywork guy to put on an RS bumper in the back, get rid of that ugly foglight and painted reflector.

https://scontent-amt2-1.xx.fbcdn.net...25&oe=59826E80

i was playing with the CDI+ box yesterday to try and influence the cold idle, and it's nice to see the engine react to the inputs of the laptop, gives you a good understanding how everything works.

I don't think i'm going to need a lot of 'recurving', because these are the numbers on my stock car, without influence from the CDI+: (all numbers are total advance)
900 RPM 5° adv
1500 RPM 15° adv
3000 RPM 25° adv
4000-6000 RPM 30° adv

So it seems that this distributor gives around 5° more advance than what a stock 911 SC distributor should do...maybe it's recurved in the past, who knows? Anyway, it's no problem with controlled fueling and 98 octane juice over here.
I do notice a lot of movement in the higher rpm's...the advance is not very stable, it fluctuates easily 3° back and forward. So that would be a big plus of locking the weights and using the CDI+ to control the advance. Something for the near future.