Louie928

Jim,
How did the timing retard show up due to bad motor mounts on your car?

FUSE69

Hi Tony,

I read through the thread that you started about this issue and figured that I probably have some similar issue.
Likely an intermittent error due to some crappy wiring....

What threw me off a bit is the fact that there is no 'global' 6deg retard shown in the 'knock retard / cylinder' display...

John Speake

Usually RPM and load have to rise above a threshold for the retard to be enacted. So the message is a little misleading. Shouild be more like "...if you put your foot in it I will retard you 6deg"

jcorenman

Louie, the motor-mount theory is just that-- haven't had time to swap the mounts yet to prove or disprove it. It happens randomly but when it does happen the knock-retards all go to 6 deg and stay there. Doesn't matter if the engine is idling, cruising, closed-throttle with fuel cutoff-- until the ignition is cycled off and back on. This was looking at the logged KR numbers-- I don't recall whether the EZK-monitor page also showed 6-deg retard across the board.

EDIT: I found a log file where it went into knock-retard, which also showed Ignition advance as well as KR's. It went into knock-retard under moderate load (1970 RPM, MAF-signal 143, EZK-load 51) and timing didn't change-- stayed at 31.6 deg. And another when it went into KR on the dirt road to our house, closed-throttle at 1100 RPM, again no change in timing. That's all consistent with John's comment that the EZK only retards the timing under higher loads, but the logged KR numbers continue to show 6-deg retard.

Cheers,

Tony

yup...after repeated runs trying to figure it out, thats what i concluded also. It was fine just driving around but once i got on it, the 6 degress retard across all cyls appeard

FUSE69

Well I managed to finish work early today to spend some quality 'one on one' time with the 928...

Finished wiring in the Sharktuner, so I now have the WBO2 reading.

Then went on to try and find the issue with 'ignition retard' warning
I checked over the Hall sensor wiring, wiring itself looked OK, but was routed right over the HT lead to the coil!
My immediate thought was, 'that can't be good'... anyway fixed that and rechecked with the Sharktuner.... still no joy!

So thought I would do a datalog of startup...
Which shows 1 knock count as the ignition is switched.... I've no idea if that's normal?



Also did a few datalogs of driving down the road, but it doesn't register knocks and doesn't register any retard over KR1 - 8
Perhaps I was unable to register enough load... I live on a gravel road... so everytime I stuck the boot into it I just started going sideways...

After messing around a bit more, this finally showed up.



So I guess I now know where to look, but as it was pretty much dark outside by this time, I packed it up back into it's garage at least happy to know where the problem lies.
(Unfortunately the garage it's in at the moment has really crappy lighting)

Another question though.... whilst wiring in the WBO2 I found the below pluged into the NBO2 socket... is this normal for a Non-Cat model?
(appears that earth and signal are looped together

AO

You might want to check the hall sensor wiring on the harness side. I found this on my '87 project car. The wires were bare and touching each other. I think I fixed it - waiting on the cable to hook up the ST2 to it. Should be here tomorrow, but the STer is back in Michigan, so no love until next week.

John Speake

Hi Ben, I wouldn't read too much into that knock glitch on igntion switch on.

The front knock sensor warning is significant.....

When you replqaced the knock sensors, did you fit the newer type with gold plated connector pins ? If so, they were the wrong type for your early car, because your car's cableform has tin/lead mating connectors. Mixing the two types may cause early corrosion.

The shorting link you found on the O2 sensor is standard fitment for non-cat cars.

FUSE69

OK, thanks John.

Not sure what knock sensors I fitted... I had ordered them with a bunch of stuff from '928 Specialists'... I had no idea that there was a difference.
I'll disconnect them tomorrow and see what they look like... If they are corroded, but salvageable, will putting on some dielectric grease after cleaning help at all?

Also, is it worth replicating the 'shorting link' in the connector block on the supplied O2 sensor harness?

John Speake

Hi Ben
You prbably be OK if you can clean them up and add the dielectric grease. You do need solid connections because the signal levels are very low. Also of course why the slighest spurious signal will freak out the EZK knock inputs.

On the paper copy of the harness diagram I sent with the ST (?) it shows that the NBO2 input of the LH can be bridged to ground on the harness for non-cat cars. Alternatively you can select "force non cat mode" on the LH Paramters screen of the ST2.

Damn, I just realised I missed that note about the NBO2 link from that new photo of ther harness I sent you :-(

worf928

The later knock sensors have a blue sensor-side connector and were fitted starting in '91. The '90 and older knock sensors use a black sensor-side connector.

If you apply an anti-corrosion agent (I prefer "CorrosionX") you shouldn't have any problems mixing the blue knock sensors with a pre-'91 harness. The blue connectors do not crumble after 10 years like the black connectors.

John Speake

This is to announce a significant software upgrade for the SharkTuner Mk2.

These changes are in part a response to customer requests for improved datalogging and in part to fix reported bugs. Many thanks to everyone who has reported and made suggestions. I hope to send an new install file to all registered ST2 owners in the next day or so. This new version of software is Ver. 6.0.9 and runs with ST2 firmware 6.0.0.2

The list of enhancements are :-

1) Datalog files have been extended a maximum of 10,000 lines, with automatic creation of a new run file tab and data rollover up to the maximum of 10 log run files allowable on the screen at the same time. Each file gives approximately 15 minutes of datalogging at 10 samples/sec.

2) Selected Datalog variables, trigger option and selected data rate are stored between SharkTuner sessions.

3) Datalog column titles always stay in the viewing area at the top of the columns

4) Reported Temp 2 readings are now corrected to give equal readings between LH and EZK.

5) The problem of injectors sometimes pulsing with just ignition on has been fixed.

6) Fixed an engine no-start bug with certain screens selected.

7) Some data glitches caused by various versions of laptop/operating system ( e.g. Lenov S-10 Netbook with Win7) have been fixed.

8) EPROMs made from ST2 bin files will now work with Bosch Hammer and Theo’s tester.
(do not work with Flashing code tester e.g. Spanner)

9) Fixed an issue where some EZK settings on the “Ignition Parameters” screen were reset to factory defualt values when EPROM revision was upgraded. (i.e. when loading
an old bin with a new exe).

Many thanks are due to Niklas for working on the software when he has so many other pressures on his time, and also to Jim Corenman who has tested these modifications with his impressive array of laptops :-)

jorj7

Very cool John, thanks.

DR

John,

Great job, thanks to you and Niklas for continuing to make the SharkTuner better and better!!!

dprantl

Where can we download this version?

Dan
'91 928GT S/C 475hp/460lb.ft