156 replies to this topic

[Sprocket]

Hi Ok

I'll do that tomorrow

But I don't understand all

When you says With MEMS-ROSCO, move the bypass motor to idle 25% This is with button "idle decay" ??

[martinrub]

If someone has messed with a factory-set screw-stop that should to be tampered with, then it is all the more reason to follow genpop's advice to check that an incorrect injector has not been fitted. It is also possible that a worn/damaged/missing O-ring on the injector is allowing fuel to leak past the outside of the injector and drain into the inlet manifold when the engine stops, so that when you start, there is an excess of fuel and hence a lot of black smoke.

Fuel leaking past the injector would also explain genpop's observation that STFT is more negative at idle than at speed.

Unless you had the correct O-rings for the injector, you could try swapping the injector with your spare one (and risk damaging its seals) or replace the complete throttle body with the original one. Hopefully, the stepper-motor factory-set stop screw on that has not been tampered with.

(When technical control is refused in France, can you still legally drive on the roads?)

Edited by martinrub, 03 March 2018 - 06:47 AM.

[gdudu]

 

Thanks Sprocket, this is very clear for me like this, you cannot do better   

Martin,

I never have desmonted an injector, I don't know what it look like, then I am not very able to see if correct, I even don't know where it is (I suspect) I will try to find

After negative Technical control, you have (in theory) 2 months to correct, and you can drive.

But you can also drive as long as you like until police don't ask you the papers.

Technical control is to make for old car, every 2 years.

I was driving like this since 1 year, but my wife didn't like this a lot (she was driving...)

But in fact, I have never been arrested by police since 20 years

 

Today, automatics radars are more numerous than policemens, and they don't ask papers, only ask money

[martinrub]

I understand. Maybe you can remove your friends registration number plates and put them on your car!

You have made good progress with the idle speed, but that part is still not right: I notice 2 things are still not happening -

1. There is still no activity on the idle switch display. Its stuck at zero. When working properly, it will look a little bit like the Loop graph in that there are lots of jumps from zero to High. Every time you take your foot off the pedal it should drop to zero and every time you put it back on and keep it on, it goes High. So MEMS is not yet learning where idle is.

2. On a normal system with a hot engine, when you open the throttle, the Idle Air Control (stepper motor) increases slightly in preparation for when you close the throttle (and then it drops back slightly). Yours isnt doing that; it could be that the stepper motor stop is not in the correct position. With your engine at 80C and idling at 890RPM, your IAC (Idle Air Control) shows a position of 96 steps. I am used to seeing lower, and sometimes much lower numbers at idle engine speeds. But then you are going to try to adjust that. It is NOT idle decay: idle decay adjusts how quickly the engine returns to idle when you release the pedal. If its too quick, it might drop to, say, 700 RPM before coming back to the correct idle speed. Its idle speed plus and minus that you would adjust, but Im sure the stepper motor stop screw has to be set to its correct position first before any adjustment is made to idle speed in MEMS (and then never moved again).

So those 2 things tell me this part (idling and throttle position) of the system isnt quite right yet.


(Im disappointed that your throttle still shows an angle of about twice the true angle even though you are now using a different logging software. But if MEMS thought your throttle was at 30 degrees, you would be idling about 2000-3000rpm, so we can put that down to an error in the logging/display, especially as the developers have seen this error before.)


If you do find the original injector, and the rest of the original throttle body unit is good (eg stepper stop screw is still at factory setting), you might consider swapping the whole unit. A logfile with that original unit would make for an interesting comparison.

Edited by martinrub, 03 March 2018 - 09:04 AM.

[martinrub]

To test if fuel is leaking out of the injector/housing overnight you could perhaps look down into the manifold before you start up in the morning and look for fuel. If you put a cloth or paper towel down overnight to catch any fuel as evidence of leakage, make sure it is impossible for anyone to start the car until it has been removed.

[Sprocket]

I think we need to address the basic adjustments first, then do simple tests before going balls deep into injector size or Orings.

Larger injector will not affect idle control. Car is running great with Le Mans 24hr performance 😉 let us come back to rich mixture.

One step at a time. We are heading in the correct direction.👍

Without history of the engine, there is questions. Has camshaft been changed?

[gdudu]

Yes I will start with simple, 

Martin, I don't think to have an iddle switch on this car : no switch around the pedal, and I've seen there was no switch on theses cars (SPI 1995). Or the switch is invisible ?

I will today try to adjust iddle as you told me,

No camshaft has not been changed by me, and I don't think it has been

I bought the car in a state of origin, exhaust pipe and other, I didn't see any change, inside, outside or in the motor, then I don't think that previous owner has done anythink. It was the mother of the vendor (that's what he said, and I beleived him)

Edited by gdudu, 03 March 2018 - 10:34 AM.

[gdudu]

Here is the log file

The cable was almost good, I didn't change many

Attached Files

•  2018-03-03_08.41.txt   45.74K   7 downloads

[martinrub]

No physical switch after 1993; instead the MEMS software learned over a period of time where idle (ie closed throttle) is.      So there was no longer a need for a physical switch.    Something less to go wrong.

[genpop]

Hi gudu,

attached are some pictures from a simular injection body.First picture is an exploded view.Second one shows the injection nozzle.with its gaskets.Third one is the intake air control valve and fourth is schema of throttle pot.

 

 Explosionszeichnung.JPG   56.38K   4 downloadsJPG]  Einspritzung.JPG   54.73K   2 downloads

Sprocket wanted to tell you that the cable is too lose.

Attached Files

•  IAC-valve.JPG   41.36K   2 downloads
•  TPS-sensor.JPG   33.31K   0 downloads

[gdudu]

And another log at iddle, with 3 or 4 accelerations at the end

Thanks Genpop, in deutsh I am worst than english, but it is very useful 

Attached Files

•  2018-03-03_11.57.txt   83.36K   3 downloads

[Sprocket]

OK

 

With these tests, I am convinced that the stepper motor works. Idle speed control should work.

 

 

 

 

Next

 

• with hot engine
• make log with MEMS-ROSCO
• Idle Engine
• Monitor "IdleairContPos" (see picture)
• Set the stop screw so that "IdleairCotPos" is just below "IdleHot" (see photo). Make a slow adjustment. Allow the ECU time to adjust. (make screw long. See Photo)
• If things go wrong, return to the previous setting and report

 

Edited by Sprocket, 03 March 2018 - 11:45 AM.

[genpop]

hi gdudu,

have you tried setting the iac on the fault codes tab and have you tried fuel trim minus on the emission tab.

Is memsanalyzer now working?

Show us your email adress hereand i send other mems-rosco .You may delete email adress a few minutes later.

[Sprocket]

STFC, whatever. Lambda oscillates well, so the stoichiometric ratio is good. Maybe an exhaust leak, but the emissions will soon pass. The coolant temperature was a big problem ....... Solved

[gdudu]

Hi

Genpop, 

MemsAnalyser is not working with MemsRosco log files. I've opened thoses files on Excel to see something, but impossible to open

I think I have not the same verion of MemsRosco than Sprocket who have 2 more tab : lambda & readlog

 

But I had nothing 1 week ago, then I'm happy of the work made by Colin and Leopold and perhaps some other, I don't know.

 

Sprocket

This morning, Ive made a log file :

Driving 10 min to heat the car, and at iddle to adjust as you asked me

But, impossible to move the value of "IdleairContPos", always at 93. I've tried in both direction for the adjust screw. The iddle is growing, or droping. I guess you will see that in the log file

However, when I cut contact, I see the stepper moving to a stable other position, always the same, and "IdleairContPos" is going to 105 (if my memorie is OK)

 

Strange, the ECU seem not to see that I am at iddle ?

 

PM : I have accelerate 4 or 5 time to see if that could wake up the iddle position to return at a correct value (850), but no

Attached Files

•  2018-03-04_11.34.txt   560.45K   3 downloads
•  Iddle trying to adjust screw.jpg   33.51K   3 downloads

Edited by gdudu, 04 March 2018 - 11:33 AM.