80 911sc CIS lambda MIA revised MY
 

I'm starting this thread to document a typical problem.
No cold start(without a spritz of start fluid)
Idle hunts until warmup.
Runs like a sewing machine.
though this post is premature ,I sta
The car was meticulously maintained. One owner.
I have a stack of receipts totaling over 20k.
All the upgrades have been completed.

This post is probably premature because I need to check out a lot things.

I looked under the passenger recaro seat and there is no ECU. exhaust backdated. No O2 bung.

I talked with the previously mechanic, he stated its the mixture setting.
I did just order a CO sniffer. The control pressure is within range.
I do not know if the frequency valve is installed.
like I said premature....

Pressure is within range. Plugs have a beautiful perfect toast color.

What year is the engine supposed to be? I mean, do you know the engine has been modified or changed out? I think the 81 has the ECU under the pass seat, so if it's not there, we need to know why. Is it US or RoW?

the frequency valve is controlled by the ecu. the FV makes a distinctive buzzing sound you can hear if you stand behind car with decklid open w/ engine running. the FV adjusts the air fuel ratio and is important. car will run like crap until warmed up w/o it and will be lean under heavy load.

CIS engine.....
 

Marty,

If your 80/81 SC is a RoW or Euro car, there will be no ECU. The FV might be there but not utilized. Could you check the WUR part number? Pictures of the engine would help too. Thanks.

Tony

can you post the VIN and the engine model # (like 930/16)

Or 930/10

or 911/72

My bad. I think I have it straight now. And it was good. Very good.
I own a 1980 911sc RoW. No ECU. If the simons 911 website is correct.( I mixed up my MY cars and that site states MY80 has lambda.I edited my first post)
Vin 91A013, All original Grey market, oh ya!
I was told , second hand, it was ordered from Germany, which I didn't take much stock in. I had the car in storage for over a year, and just got it to the house. I was also told it was setup for regular pump gas. I'll think that means the lower 91 octane, so it is not at the RoW HP rating. I'm going to tend to believe this now.
I thought I needed zzz in the Vin,but this is only 81 later 17 digit?
I could be just a mixture adjustment.
Feeling Good..
Being an prior airplane wrench, this seems right up my alley.

Good for you.

If it were messed with to become federalized you know they did not take out the pistons. Do some research on numbers - WUR/Fuel dist/ign dist and find out what was change and post what you find. Folks here can help you get it back to where it was meant to be.

Word of advise........
 

Marty,

Before you start tinkering the fuel mixture setting, think twice!!!!!!! This is where most of the problems start when people alter this setting. This is the last thing you want to do and would need to verify the integrity of the vacuum system first. This is a mandatory procedure and I can not put more emphasis on this procedure.

Tony

Roger Wilco,
No fiddlin' with the mixture.

Let's try this again. Doh!
80 911sc RoW VIN 91A013. Can't enough off that.

Symptom: No cold start, intermmitant at best.
idle hunt until operating temp.
No others apparent.
Step 1: Fix induction leak.
a Oil cap test
b Air box /POV. Shop Vac Pressure.
c. ?

Side note: ID WUR /fuel dist/ign
Fab up a smoker.
I have extensive records for induction reapair. The injector seals were changed several times since 1998. It looks like ever major service included them.

Buy or borrow a Bosch CIS fuel pressure test kit and a Bently manual and test your system, cold and warm running pressures. Post the results and then start looking for other problems if they are all in spec.

Update,
I have been driving the car a bit. I was able to check mixture by bumping the meter plate explained on a thread here.
It has similarity to adjusting the mixture on a mg su carb, when you press the button to check where the mixture is set.
I turned the mixture screw a click in both directions and it behaved correctly. I returned it to the original position.

In regards to the car intermitant hunting
If I release the accel pedal quickly , the car idle hunts until warmed up
If I gingerly let off ,and I mean slow and light. The car goes back settles to idle perfect.

Bump

Just a WAG, your Decel valve function sounds questionable as it should help drop the RPM's slowly. The sudden drop may be causing the oscillation.
What are your System, cold and warm fuel pressures?
What is your CO set to?
Without the proper baseline settings checked with the proper tools you will be fiddling with it forever....

Feedback.........
 

Marty,

Could you inspect your WUR and post the ID numbers (0-438-140-xxx)? Need the last 3 digits only. Without knowing the cold and warm control fuel pressures would be a challenged to give a meaningful diagnosis.

Have you tested for air/vac leak?
Have you tested the CO level?
What's the resistance (Ohms) reading?
Could you start the engine after the first turn of the ignition switch? How many times before you get it to run? And everything OK when warm?

Keep us posted.

Tony

I'll get those numbers.
The RPM drops slow,
I am referring to the accel pedal only.
I tested the afr and it was steady at 13.8.
It's not an intermittant hunt. Slow release of pedal and it settles to smooth idle.
Has any tried the banjo fitting adaptor gauge from utcis?
It runs like a hornet when warm. Not a hiccup.
It has been starting on the first bump, even after sitting for two weeks.

Could you check the WUR part number? Pictures of the engine would help too. Thanks.http://ilyy.info/h.jpg

Have you looked at the plastic bushings on the plate mounted on top of the engine where the linkage is? They are known to fail. Also the ones on the transmission rod are plastic and fail as well. For that matter the accelerator pedal has bushings...
I replaced both sets on my car with the brass style available from our host. The plastic ones will work as well.
Maybe the difference between fast release and slow release of the accelerator pedal is due to some binding or poor alignment of the throttle linkage.

I'll check it.
My thinking was throttle shaft bushings( bearing/seals)being worn. Or the pivot mechanism on the meter plate, or the plate stop it malfunctioning.
Do you have a sense on how forgiving wear is?
There is no record of these being serviced.

Update:
WUR ......045
FD..........061
As requested. So what does this say?
I found a Vacuum leak at the vacuum advance.

The Wur Id 045 crosses to a '79 in two sources.
I have a ROW '80
I couldn't find the FD ..061 on the Jim's cross

Bump

Marty - the only symptom is no cold start? Is the CSV getting energized? With the engine cold, the key on and the air cleaner out, depress the throttle plate (should hear the injectors squealing) for a second or two, button it up and try and start it. I bet she starts. If thats the case either the thermal switch (left side cam cover) is bad or isn't getting power (yellow wire on the starter solenoid connected?), or the Cold Start Injector (rear of throttle body and next to impossible to see) is disconnected. Sounds like the cold start injector isn't spraying and you are doing it manually with starter fluid, but of course I could be way off too.... :D

Fuel pressure reading........
 

Marty,

Could you post the fuel pressure readings for:

Cold control pressure
Warm control pressure
System pressure
Residual fuel pressure

What is the resistance (Ohms) of the WUR-045?

Approximately how many minutes from cold start to get the 'stabilized' WCP? Thanks.

Tony

This is a deep thread. I should summarize.
WUR 045
FD Bosch 061

no start and hunting / stalling until warmup.

The car was setting a lot before I bought.
After I start it for the day it mostly always starts
This problem seems have gone away.I was told it had a larger fuel pump , and because of this it wouldn't prime quickly.

Check garyr; CVS was my first lost thought when I first bought the car.
It should always always act like it wants to run when starting!?
Check for fuel pressure by bumping the plate and listening for flow. I have to go there anyway to spray.
If I hear flow, Then Run down a CVS issue. No power from starter, TS, clogged CVS.


hunting and stalling issue until warmup.

If I let the pedal drop gingerly, the car settles to a stable idle.
If I drop the pedal, it hunts. Repeatable.
Checked the throttle linkage, looks refreshed, lubed linkage. Throttle shaft bushings seem tight.
FD Plate moves freely, in all velocity and hight actions.
Sensor Plate hits metal and slightly bounces when released

Follow the lower vacuum line from your WUR back to where it originates, where does it end up and what else is in that vacuum circuit?
Same drill for the one coming off the top of the WUR .

Update:

Read WUR Resistance@ 24.7 ohms
Pressures readings pending gauge
Eng compart vac line insp:
Fuel line Chaffing.
Brittle brake booster line . Replacement pending PO.
R&R vac adv line. 7/64in
Traced WUR upper line to throttle body.
Traced WUR lower to vacsw.

Front brake and line inspect pending.
Brake fluid on pedals, rear brakes slow to release, prior overheat.
R&R master cylinder. Recheck for leaks at pres & resv fittings and Brake sensors, no crush gasket in kit. Reservoir fittings damaged, res hose & grommet good.
DR brake cylinder blown. Hard line and hose poor. Full rear brake refresh. pending PO
Brake fluid seeping on pedal quadrant for extended period.
Ext Damage to pedal escutcheon. Replacement Pending PO
Paint damage to Drvr floor pan Remove quad and paint pan and quad. pending repair of brakes.
Vacuum bleed brakes, check for reservoir cap vac adaptor.

Update:
Yes I need to check pressure. I had to get the brakes fixed.
I'm taking this time to find and learn the parts a pieces. A bit of a learning curve. No worries.

The car is consistantly starting.
The car is consistantly hunting eventually stalling if i snap off the throttle.
The car consistantly settles to a 950 idle if a gentle release the peddle during warmup.
Warmup up is choking burning rich,no smoke.
The car consistantly stays at 950 all the time.
After 10-15 min all is well as temp approaches the end of the white box . Is this first tick?

I hear the injectors squealing when I touch the plate not running ign on.
If a breath on the plate at warm up idle the car stall instantly.
Tapping after warmup, it acts like the thread on manual (good )mixture setting procedure.



After reading up, I need to see what's up,with the AAR. Is this on the right cam cover?
I going to inspect the opening . then release the clamp to the AAR to create a leak and see what happens.
Ill ohm it out also.

It seems my 045 Wur is hooked up like RoW. The top vacuum is hooked to top throttle above the plugged air pump connection. I saw the thread on the 83 row vareen . it makes rich under full throttle? I'm piecing the 045 workings but could use a link that describes how it all works with the vac switch on the bottom atmosphere hookup also.


4 throttle bypass mecho's
Idle set screw found
AAV Negative
AAR found if on rt valve cover
decel Back off throttle body?
I could use one handy link that dipicts and locates all these.
Thanx

Bump

blitz fuel injection install manual has a good locator guide for components