MembersPage/PerBoddum

With this 12-1 trigger signals and high compression, the missing tooth is sometimes shorter (downto 1.55) than the normal tooth (upto 1.62) so this will not work.

As a bandaid 2 holes can be shut with tape as a test (conversion to 12-2 wheel). Or install a suitable wheel (this wheel is, though the most unfortunate choice for missing-tooth pattern - reason below -, would work with a normal engine of lower compression, or higher flywheel mass; but not in this super-engine).

Primary and camsync trigger is hall.

We couldn't set up detect trigger sequense from Nissan 300ZX HALL module with 12-1 triggerwheel

Car is race V8 engine, high compression and cranking at approx 80..113 rpm. The cranking RPM varies very much due to the high compression.

It's been known since long, that 12-1 is the most prone to sudden pulse-time variation at cranking (especially with high compression), so it takes more work (eg. analyzing triggerlog - the numerical output is more descriptive in this case - and setting advanced filtering threshold) to set it up right (and best to avoid it). Better options:


When turning distributor by hand with ocsilloscope connected there is no doubt where missing tooth is. Allways 11 tooths between the missing tooths and the camsync signal comes on triggertooth 0 (first tooth after missing tooth)

I have also tried disabling camsync all together, but it makes no difference.

When turning the distributor by hand (approx 80..100 rpm in vemstune) sometimes the sparkplugs ignite.

The rpm signal in vemstune (1.5.24) seems to be very stable. No flickering rpm signal.

Triggerlog when engine is cranking. (with wrong ignition output settings, but trigger setup is correct)

http://www.vems.hu/files/perboddum/cranking.triggerlog

Triggerlog when distributor is driven by hand

http://www.vems.hu/files/perboddum/turnbyhand1.triggerlog

http://www.vems.hu/files/perboddum/turnbyhand2.triggerlog

Vems config

http://www.vems.hu/files/perboddum/setup6.vemscfg

Picture of triggerwheel 12-1

triggerwheel.jpg

If you don't change to a better wheel (eg. to 12-2) at least check position


Per i have reviewed your triggerlogs and indeed the periods between teeth seem very irregular.

1) Lets start out with with following, could you make a triggerlog of engine cranking 8-10 seconds without injector and ignition fuse to verify if the irregular periods are caused by some noise issue.

2) Secondly could you make another triggerlog (again 8-10 seconds) but then spinning the trigger not by hand but by some something with stable rpm (perhaps use a battery powered drill), that way we can verify, if with stable RPM the trigger periods are even.

If you upload both these triggerlogs to your memberspage i will review and provide hints on how to proceed.

Best regards, Dave


Thanks Dave

Scope of triggerwheel 12-1 with power drill at approx 200 rpm

IMAG0447.jpg

IMAG0446.jpg

I have done some more test with power drill (50...120 rpm) and the distributor connected to Vems.

Vemstune displays the rpm but as soon as rpm drops and then gains rpm again I often get PRI.trig error in Vemstune and the sparkplug stops sparking.

It seems to me that it is a combination of low rpm AND varying rpm at the same time that confuses Vems.

I can have steady 60 rpm and there are no trigger errors and the sparkplug ignites

Tomorrow morning I will try install the distributor and make the logs


Hello Per,

When reviewing your scope shots it seems there also is a very slow rise rate on the primary trigger pulses (red signal, ch1) could you set both probes to the same amplification, set the scope Y range the same for both channels, trigger on yellow signal (ch2) rising edge and make a much smaller timebase shot so i can accurately see:

1) falling secondary triggger (yellow, ch2) in center of screen and one or two primary edges (red, ch1) left and right.

2) additonally please supply the VEMS triggerlogs (.triggerlog files) as requested in previous query.

3) make sure the secondary trigger is enabled and connected to the VEMS when making these.

Best regards, Dave


Distributor connected to Vems and drill operated.

http://www.vems.hu/files/perboddum/drill1.triggerlog

http://www.vems.hu/files/perboddum/drill2.triggerlog

I cannot make a triggerlog or normal log, because Vems constantly looses the serial connection (physical serial COM1, not USB adapter) during cranking. Vems supply voltage is around 9.35 volt during cranking.

Note:Battery is in the back of the car.


Hello Per,

If the VEMS looses serial connection during cranking this means the ecu resets (most likely because of voltage dip during initial cranking engage) but if the ecu does not reconnect during cranking there might be some problem with the integrity of your GND wires from battery to chassis, GND from chassis to engine or VBATT cable from battery in the back to the engine. While performing the other checks it makes sense to verify these also (for good connection, corrosions, sufficient size etc.)

Best regards, Dave


Thanks Dave.

The car is rebuild from scratch with new wires in 2009. No rust or corrosion what so ever. Have only run some 4000km.

Connected 2 batteries and the engine fires up, but still looses sync at 1500 rpm. No camsync.

http://www.vems.hu/files/perboddum/running1.triggerlog

http://www.vems.hu/files/perboddum/running1.vemslog

With camsync.

http://www.vems.hu/files/perboddum/running2.triggerlog

http://www.vems.hu/files/perboddum/running2.vemslog


Hi Per,

Nice to see it running, but in your triggerlog with CAM sync i do not see secondary trigger showing up (perhaps you did not power cycle the ecu after making the changes in configuration ?). Before attempting anything else we should verify that all triggers are in working order _without fuse to INJ and IGN_ at cranking.

Very important in your running1/2.vemslogs, CLT/MAP IGN adjust table is not filled reasonably, please correct before attempting any further tests

Best regards, Dave


Hi Dave

Camsync is connected to EC36-13.

With scope connected to pin13 on Vems printboard I get a fine camsync signal. Why is it missing in the log.

I am pretty sure the previous triggerlog with camsync is recorded after a reboot.

This triggerlog is for sure after reboot.

http://www.vems.hu/files/perboddum/running3.triggerlog


Hello Per,

I have consolidated my request to single block perhaps this clears its up.

When reviewing your scope shots it seems there also is a very slow rise rate on the primary trigger pulses (red signal, ch1) could you set both probes to the same amplification, set the scope Y range the same for both channels, trigger on yellow signal (ch2) rising edge and make a much smaller timebase shot so i can accurately see:

1) falling secondary triggger (yellow, ch2) in center of screen and one or two primary edges (red, ch1) left and right.

2) Lets start out with with following, could you make a triggerlog of engine cranking 8-10 seconds without injector and ignition fuse to verify if the irregular periods are caused by some noise issue.

3) make sure the secondary trigger is enabled and connected to the VEMS when making these.

To summarize, before we have verified correct operation of BOTH triggers, no starting attempts (with fuel and spark) are required (even cordless drill tests are suitable for these scope tests, perhaps easier to perform than cranking the engine all the time).

Best regards, Dave


Hi Dave

Cranking engine triggerlog

http://www.vems.hu/files/perboddum/cranking2.triggerlog

My Vems config

http://www.vems.hu/files/perboddum/setup12.vemscfg

Scope with distributor (connected with 12volt and 1K pullup on trigger+camsync) drill operated.

scope1.jpg

scope2.jpg

scope3.jpg


Hi Per,

The scopeshots look perfect, i still suspect scope amplification difference (1X/10X) resulting in the X 5v/50v range to get same height on screen but lets not worry about that now.

I tried to review cranking2.triggerlog but the file seems to be empty. Could you re-upload or verify ? Thanks.

Best regards, Dave


Hi Dave

You are right. One probe set to x10 and the other x100.

Cranking triggerlog uploaded again

Have updated vemstune ini files from web. Was missing CLT/MAP ign settings. This solved loosing sync at 1500 rpm.

But it seems I still don't get camsync into triggerlog and vemstune signals Less sec.trig.

Trigger with camsync falling.

http://www.vems.hu/files/perboddum/cranking3.triggerlog

Trigger with camsync rising

http://www.vems.hu/files/perboddum/cranking4.triggerlog

scope of both signals during cranking. Watch the camsync.

Why does it behave like that when connected to vems. Both signals comes from the distributor Nissan hall unit.

scope4.jpg


Hi Per,

Great to hear updating ini file manual update provided you with the correct ini files to match your firmware (as recommended on GenBoard/UnderDevelopment/FirmwareChanges).

I have no idea whats going on with your secondary trigger signal, it seems some kind of noise superimposed on signal. Secondary trigger also does not show up in the triggerlog(s). My suggestion would be to disable secondary trigger for now, you are running distributer ignition anyway.

Make sure to check if your tdc calibration is set up correctly (with timing light) before attempting any further tuning.

Best regards, Dave


I still have problems with enabling camsync.

We have changed from 18K to 2.7K pullup and the scope signal is now good on pin13, but no signal into Vemstune.

We have tried firmware 1.2.23 and 1.2.11 but no signal in Vemstune.

It seems that some components for camsync (hall) is missing according to Peter Jensen.

Help needed please

board1.jpg

board2.jpg


sec.%20trigger.jpg

16/3-2014

Hi Per

It seams you need a resister on your board.

This resister is a 0 Ohm so you can solder a thin jumper wire and sec. Trigger will work


16/3-2014

Camsync now gets into vemstune after soldering the jumper wire


16/3-2014

Trigger sync request for 12-1

Issue using pri trigger only:

When cranking vems read the pre. Trigger signals nicely but when it start one or two cylinders vems loose sync, see log files her:

http://www.vems.hu/files/PerVolvo/v3.3_u008135-2014-03-15-16.31.04.triggerlog

2 batteries have been connected doing all the test on this site so far, but we have to use only one battery at race events.

Also this is a high comp engine and maybe it rotates too slow/quick when it fires up. (see top of page)

Cranking is 70..113 rpm and varies much due to high compression)

Do we need a new firmware low tooth count or what could we try.

Thanks for your time

Peter


Hello Peter & Per,

Could you elaborate to exactly what the problem is you are seeing ? During previous logs which were submitted by Per (admittedly using dual batteries) the engine was (reportedly) running fine.

Cranking such low (and also unstable) rpm is not recommended and very hard to sync to. Try to get cranking rpm up to at least 120-150 rpm stable (and i suspect any issues you might be seeing will be solved).

One possible solution (we actually recommend this for 12-1 in help): http://vems.hu/vt/help/v3/v3_primary_trigger_settings.html, more specific section: "For 12-1 missing tooth wheel" is enabling advanced filtering with recommended thresholds.

Please report if this benefits you.

Best regards, Dave


17-03-2014

Hi Dave, thanks for your time

Note. Camsync is disabled.

There is no way to get the cranking speed higher than 113 rpm, even with dual batteries. Around 113 rpm seems to be startermotor max. (motor is new). Same startermotor is on a Rover SD1 V8 and it is also running at around 113rpm and it is starting fine (has other brand of EFI controller).

When we sometimes gets the engine started (after 10..15 sec of cranking because of sync loss) it runs fine.

The problem is that the sync loss happens just when the engine starts to ignite a couple of cylinders (and rpm rises fast) and then the ignition is cut and Vems starts to resync and the same thing starts all over again.

I have tried many sorts of "Advanced filtering", but it does not seem to have any major impact. I can, however, adjust the filtering so much that I don't get ignition pulses.

Per


Hello Peter & Per,

I will run some tests locally to verify operation during fast rev up from cranking, using 12-1.

Best regards, Dave


17-03-2014

Thanks dave.

Here is the latest log where the engine starts.

http://www.vems.hu/files/perboddum/v3.3_u008135-2014.03.15-13.23.22.vemslog

If I drill operate the distributor and mount a sparkplug to the coil and vary the rpm, I can see that sometimes the sparkplug stops igniting. Vemstune also reports Less Pri trig.

It seems that it is every time the drill changes a little in speed.

Per


18-03-2014

Hi Per,

Your trigger reference tooth table has this sequence:

07654321

03690369

Sorry if I have understood this wrong, but since 0 shows h10 on mouseover, and 1 shows h11, it might be worth a shot to change the table to:

07654321

09630963

\Alex


18-03-2014

The engine runs fine when it finally starts after some 10..15 seconds of cranking

Per


19-03-2014

Thanks for the suggestion for 12-2

I have now tested a 12-2 distributor on the car with a powerdrill and a

sparkplug connected to the coil.

The 12-1 wheel I have taped one hole next to missing tooth so now it is 12-

2.

Vems now seems much happier. It is now very difficult to provoke trigger

errors at (60...200 rpm), even at varying rpm.

Sparks rarely drops out,as it did before (during resync)


12-2 have now been tested in the car. It sometime still have trigger errors when cranking. Each time I start the engine there is 40/60 change of trigger error. When cranking with no trigger error the engine fires up after 3 sec.

The problem seems to be the width of missing tooth. Will I have similar problems if I use a 24-1. 24-1 missing tooth width in relation to trigger tooth is the same as 12-1 ??

In my case I think 24-2 might be better ??

Per


2014-04-01

Changed the triggerwheel to 24-2.

Now the engine fires up within 3 seconds (remember slow cranking) and only on rare occations it looses sync when cranking. I think that now it only looses sync in some 15% of all crank attempts.

Do you have triggerlog when that happens ?


4/4-2014

We are investigating all kind of trigger wheel we did make and run 24-2 now and seams promising using only pre trig. If we try sec trig it is hard to start and losses serial comm so we scooped the 12v supply near ecu and it make a short drop to 6.5-7 v and I think ecu restarts and therefore itīs also impossible to make a trigger log.

Question: Can we add a capacitor for backing up this voltage drop: size and where to fit it please.

Tnx Peter

Just when the starter motor engages we have a short downwards voltage spike to 6.0..6.5 volts and it then raises to 9 volt after 100ms. This causes the ECU to reset. However the the engine starts after 3 sec of cranking (no camsync)

With camsync the engine will not start.

With camsync and 2 batteries the engine starts fine (no trigger errors)

(Allow sync without camsync=Enabled)

triggerhjul.jpg


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