Leerlaufdrehzahl L251

[25Plus]

Mein Cuore geht mit der Drehzahl erst nach einem Warmstart auf knapp über 800 U/min herunter. Nach einem Kaltstart - auch wenn der Motor richtig warm geworden ist - pendelt sich die Leerlaufdrehzahl bei ca. 950 U/min ein. Aber nur, wenn der Wagen steht. Bis zum ersten Stillstand sinkt die Drehzahl normalerweise nicht unter 1500 U/min, danach bleibt sie beim Rollen ohne Gang bei ca. 1200-1300 U/min und geht erst wieder bei Stillstand weiter herunter.

Mfg Flo

[fubar]

Ich war jetzt neulich beim TÜV.

Da war die Leerlaufdrehzahl zu hoch.
Prüfer schaltete aber alles ein, und zack war der Leerlauf da wo er hin sollte. :)

[terios]

hallo alle,

Would you please show me how to read the REV pin8 without an OBD adapter?

[bluedog]

That is explained at post #09 here.

What you get at pin 8 is a frequency. That is not the rpm directly, but the ignition frequency.

To get the rpm out of that data, you take two thirds of that value. That result is the rotations per second.

To get the rotations per minute, multiply with 60.

[terios]

As usual, thanks very much Bluedog for your support.

Understand how to get the engine rpm from ignition frequency, but how to read it? I mean what and how to wire to get the reading?

[bluedog]

I unfortunately don't know.

As far as I understand, it is pin 8 at the OBDII-Port.

I don't know how the pins there are numbered and which one is ground.

And, since you have got an EJ-DE, I don't even know, if the pins of the OBD-port are identical, because in europe the L251 is always equipped with an EJ-VE.

Possibly that does matter, because when you look at the predecessor of the L251, which was the L701, there was no OBDII-Standard when equipped with an EJ-DE engine, although the port looks the same in both cases, that means, it looks identical, whether it is OBDII-compliant or not.

So, to make a long story short, The EJ-VE-L251 for europe always have OBDII. The EJ-DE engined L701 (up to 2000) did not have OBDII. Therefore I simply don't know, if your EJ-DE has OBDII or not. I suppose it has not, because EJ-DE was actual in europe before 2000, when it was not mandatory to have an OBDII-compliant port on board.

In the EU, it was mandatory from 2000 or 2001 to support OBDII standard.

The port looks identical in OBD I and OBD II, but the wiring and presumably the communications protocol are different.

So, in case your L251 doesn't come with an OBDII Interface, I don't even know if pin 8, as mentioned above would be the right one for you to get the ignition frequency. Sorry.

I can however tell you, that the OBD or OBDII port is located at the right side of the steering wheel directly behind the dashboard cover on the lower end of that cover. You have to look from the floor up to the back side of the Cover between the steering columns cover and the centre console.

You can find a picture of that connector here: https://en.wikipedia.org/wiki/On-board_diagnostics

However, that doesn't tell if it is OBD I or OBD II.

[Rokko]

I guess the attached figure may be helpful.

Between 'REV' and 'Body Earth' you have an analog signal with the ignition frequency. Hook a frequency counter (my multimeter has one) to it to measure the frequency. As already mentioned, divide by 1.5 to get the rotation frequency.

This has nothing to do with the OBD bus which you could query for the RPM with a suitable tester.

[terios]

Thanks Bluedog and Rokko for your support.

One Technician with a special tool connected to the battery he could read 650 rpm. This is too low compared to the specified 850+/-50 rpm.

Another Technician with Bosh tool connected to the DLC can't read my ECU. We tried with Cuore L2, Charade L2 and Toyota Duet but no way. Surprinsingly, it connected with Charade G2!
There was no much readings but the following:

Idle 33 %: didnt know if this is good (it is written pour mixture in another antry)
Timing 9-18: this is too much different from the specified 5+/-2 TDC/rpm


Something wrong?

[bluedog]

How can one connect to the battery and read out the idle rpm? Can't imagine that.

But if so, is it verified, that the device that calculated the rpm was made for 3 cylinder engines?

Because it seems to me that 650 is pretty exactly as much as one third to less, as if the calculator expected one more cylinder.

Concerning ignition timing: As far as I remember, you have to bridge the appropiate two pins to get valid data. There should be a label under the hood, on wich a picture shows what to bridge.

[terios]

Zitat von bluedog

But if so, is it verified, that the device that calculated the rpm was made for 3 cylinder engines?

Because it seems to me that 650 is pretty exactly as much as one third to less, as if the calculator expected one more cylinder.

What a smart point! I really think you're right: that guy didn't enter any input to the device showing it is a 3 cylinder engine!

Following your thinking, it will give a normal idle speed of nearly 860 rpm, which is good.

Now, you are complicating my life; because just before that, I was accusing the ISC valve failure

Here under all the readings I get from the first guy's device (battery connection, oil sensor inside the gauge tube, exhaust sensor inside the exhaust pipe)

CO 0.01 %vol
COcorr 0.02 %vol
CO2 8.9 %vol
O2 9.5 %vol
HC 0132 ppm vol

Regime 650 rpm

Oil T 53 °C



** Sorry for the owner of this thread, I would open a new one if this bother...