VR sync loss woes - at the boundary of my capabilities

[frogcow]

I am really struggling to overcome sync loss reason 2 from my engine when running. I am the limit of my understanding and need someone to point me in the right direction.

So I have attached all the files but what I also want to confirm is my interpretation of the sequence for setting up #1 tooth angle (deg BTDC). Here goes:

I am using my factory cam driven distributor which I have slightly modified by removing a tooth from a 24 tooth wheel to make it a 24-1.
I have selected toothed wheel in ignition settings.
At 25btdc distributor rotor is pointing at middle of no.1 tower.
I rotate the engine to TDC #1 compression, I then set my no.1 tooth angle to 90deg btdc ( which is three teeth/gaps as 720°/24 = 30 -: 30x3 = 90°btdc )
With timing set to fixed timing 10btdc
I then temp lock down the distributor, crank the engine and get it started, confirm I am getting 10°btdc with a timing light, lock it down and leave it.
Change setting back to Use Table.

How does that sound?

Also what are the missing lines in my tooth log?
When I lose sync you can see my composite log dissapears .

I am really at my wits end, even though I have installed and tuned a fuel only MS1 and I have a Mechanical Trade under my belt I still cannot for the life of me figure out what I am doing wrong.

[LAV1000]

Did take a look at your log.
You only have 1 sync error in the total log.
This only hapens in the very first starting attempt.
Tooth log also seems good.
Don't worry to much about this, start tuning the engine.

[frogcow]

when it loses sync, throttle becomes completely unresponsive. It might stall. The log may not show the amount of losses I am getting as it is the only log under 1mb I had but on my longer drives it happens frequently.

I have tried adjusting the pots to no advantage, I have tried different tooth angles around 90btdc. Both r52 and r56 are wound all the way counterclockwise.

Could you share your settings lav1000 or your msq?

Thinking about it a bit more I have been experimenting recently with different lsa lately, I suppose tooth angle would change if the exhaust cam is advanced or retarded a couple of degrees?

[elutionsdesign]

Sync loss 2 is missing tooth at the wrong time, I don't think it's related to your settings, more likely a hardware issue like slop in the distributor drive or an issue with how you removed the tooth. What motor, what dizzy, any pictures of the physical setup you can provide?

[LAV1000]

I'd be happy to share my settings, but I think you have not much use to it.
Because:
-It's a motorcycle engine, 3 cillinder
-No turbo
-Air cooled
-Alfa -N
-High z injectors
- MS2 system
- cranksensor, optical.

I will attach t anyway.
Elutionsdesign does have a point on slob in the drive to distrubutor.
Might consider to switch to a crank signal setup.
And yes if your distributor is cam driven and you change the timing it also alters ignition timing.
Can you post a partial log while driving and losing sync ?
Does the sync loss happen when you go off the throttle ?

[frogcow]

Okay I can post up later tonight

[frogcow]

My vr sensor wire has damage, five broken strands.

I will attempt a repair and then let you know how it goes.

David

[LAV1000]

My vr sensor wire has damage, five broken strands.

I will attempt a repair and then let you know how it goes.

David

I think your on to something.

[frogcow]

I have cut out the damaged section, applied some resin and made a nice flowed join and covered in heatshrink.

Unfortunately still have random sync loss #2, this is occurring at idle, when this happens the afr jumps and the engine starts to knock, the wideband picks up momentary jumps in afr.

Please see attached log, I do not know where to go from here>

I have again confirmed timing with a timing light, timing does not jump around when this happens. The engine is a CB80 daihatsu charade 3 cylinder 1 litre, turbocharged DOHC, 8 : 1 compression, distributor driven off the exhaust cam, nippon denso distributor, MS2 V3.0 using the internal 24 tooth wheel minus one tooth filed away and the internal VR sensor. VR set up for falling edge, R52 and R56 pots completely adjusted counter-clockwise, tooth log looks good, can not get a sync error log to show up any data, I have the Vr sensor wiring shielded from the distributor to the Ms2 , the shield is grounded to MS2 with the distributor end left floating. I also have some other unshielded wires running PWM in close proximity to the VR wiring however because it is shielded I havent bothered to shield those. Injector PWM and IACV running PWM. The only other problem I seem to be facing apart from the associated pinking is lack of power, as soon as I go to take off, she bogs down and wont go anywhere and sometimes stalls.

This latter problem though is a new one as I was driving it around the block on test runs only recently without the issue of bogging down.

[frogcow]

How do I test if my homemade shielded cable is working to reduce interference in the vr circuit?

Also I changed the distributor to get rid of slop.

It should be working correctly, is there a more laymans way to adjust the pots ? The manuals arent making it clear. I have the extra loggers in Tunerstudio.

[elutionsdesign]

I looked at your first composite log posted, its far from perfect, there are pages where its fine but then other pages where there are no teeth at all or maybe one tooth. It seems the whole signal is dropping out. That could be a problem with the pots, try turning r56 a half turn at a time CW and testing at each point to see if it clears up.

[R100RT]

How do I test if my homemade shielded cable is working to reduce interference in the vr circuit?

Also I changed the distributor to get rid of slop.

It should be working correctly, is there a more laymans way to adjust the pots ? The manuals arent making it clear. I have the extra loggers in Tunerstudio.

How is your "home made" shielded VR cable made? Ensure you drain only one end of the shield & best not to run parallel to any high current circuits.

[frogcow]

Elutionsdesign , okay I am going to try with the pots again this weekend. The signal is the issue, its actually non existent atm and cant even start.

R100RT, I am an apprentice electrician with only minimal wiring experience so I know the wiring is an area I can improve on. What I have done is attached the end of shielded vr pair from the diyautotune loom to my existing factory shielded vr wire and then I have added a bit more length by running a fine gauge fencing wire along the length of the signal and ground wire soldered to the shield then wrapped it all in alfoil and then heatshrink. Its only grounded at the MS2.

As far as routing its bundled with all the engine wiring temporarily until im done making changes, it runs close to the starter and coil and iacv valve so again something to work on this weekend.

[rickb794]

Have you tried installing a 10k resistor in parallel the VR?

5.2.2 of the fine manual, last paragraph.
"Some installs may find it necessary to install a resistor inline with the VR+ wire to reduce the signal voltage at higher RPMs. Typically a 10k 1/4W resistor is sufficient."
Readjustment of R52 & R56 will be necessary after installing the resistor.

More VR magic,
https://www.diyautotune.com/support/tec ... squirt-vr/

Also you might consider upgrading firmware from 3.3.2 there have been some big changes.

Have you loaded someone else's MSQ? This is like wearing someone else's dirty underwear or sharing chewing gum with someone who has gum disease.
There are many settings I feel are questionable, you may have out tricked yourself.

You have a 36-2 trigger wheel set but you describe a 24-1, which is it?
Make sure the distributor is locked (no centrifugal advance)? With the rotor pointing at #1 at 25° Timing is set by changing tooth one angle.
Spark table is flat, the motor is not going to be peppy and down on power.
You have crank wheel speed set. If you have a dist driven off the end of the cam you should be using cam speed.
4.5ms Nominal Dwell is high, start at 3.5.
If you don't have P&H drivers or resistors installed, you need some sort of current control for low Z injectors. Or your MS will spaz out because of the overloaded injector drivers.
Unplug the injectors and retest triggering system? This will eliminate any injector noise that may be screwing with triggering.
Resistor spark plugs? You must use them.
No Low resistance plug wires (despite marketing claims) there have been problems reported with spiral wound wires.
Coil mounted on and grounded to motor? Remote coils mounted on body parts can turn the body part into an ignition broadcast antenna.

Fuel stuff not related to your trigger problem....
You have 4 banks of injectors set. Do you actually have 4 injector drivers installed? On a 3 cyl motor?
Your sig shows low Z injectors, yet you are not using PWM? Additional drivers also set.
Sequential injection set not sure this feature works on a 3 cyl. Is this port injected or throttle body injected?
You have don't multiply map set. Are you sure this is the correct strategy?

Is there a reason you have chosen Alpha N tuning strategy? Does the motor have low vacuum? big cam?

If I was brought this car to make it run I would simplify this setup.
I would load current firmware and start a new project using the default settings and only change the settings necessary to make the motor run in your configuration.
I would tune it using speed density (SD)
I am not confident you can run low Z injectors in an odd configuration on separate channels without resistors. So some work in that area may be needed.
If you can easily find high Z injectors that fit and are not too big, that may be the best path.

If you are having noise problems it is best to treat the problem at the cause not treat the symptom.
Band Aids applied to treat symptoms may fail over time or may cause other issues.
Problems should be solved at the hardware level whenever possible before utilizing software solutions.

[DaveEFI]

Elutionsdesign , okay I am going to try with the pots again this weekend. The signal is the issue, its actually non existent atm and cant even start.

R100RT, I am an apprentice electrician with only minimal wiring experience so I know the wiring is an area I can improve on. What I have done is attached the end of shielded vr pair from the diyautotune loom to my existing factory shielded vr wire and then I have added a bit more length by running a fine gauge fencing wire along the length of the signal and ground wire soldered to the shield then wrapped it all in alfoil and then heatshrink. Its only grounded at the MS2.

As far as routing its bundled with all the engine wiring temporarily until im done making changes, it runs close to the starter and coil and iacv valve so again something to work on this weekend.

Go to your local music shop and buy some twin screened cable designed for balanced microphones. Replace the cable from the VR sensor right back to the DB37 connector. Only connect the screen at the DB37 end.

[R100RT]

Elutionsdesign , okay I am going to try with the pots again this weekend. The signal is the issue, its actually non existent atm and cant even start.

R100RT, I am an apprentice electrician with only minimal wiring experience so I know the wiring is an area I can improve on. What I have done is attached the end of shielded vr pair from the diyautotune loom to my existing factory shielded vr wire and then I have added a bit more length by running a fine gauge fencing wire along the length of the signal and ground wire soldered to the shield then wrapped it all in alfoil and then heatshrink. Its only grounded at the MS2.

As far as routing its bundled with all the engine wiring temporarily until im done making changes, it runs close to the starter and coil and iacv valve so again something to work on this weekend.

Go to your local music shop and buy some twin screened cable designed for balanced microphones. Replace the cable from the VR sensor right back to the DB37 connector. Only connect the screen at the DB37 end.

^ agreed! Plenty of woes and intermittent behaviour can develop from unusual shielded cable connections and combinations of materials - plus the preceding advise is well founded as well. Very few here (well myself for example) are professional electrical engineers but diligent wiring practises can never be undervalued.

[DaveEFI]

Also, making a professional job of wiring is very satisfying. Needn't be too expensive either if you get a loom from a scrap yard and use that as a source of the cable. But do take note of the colours you use. Used connectors can be economical too, if you source new terminals for them.

[frogcow]

Okay thanks for the tips, I have procured some double insulated twisted twin double shielded instrumentation cable.

To remove the pins from the db37 connector I need a dsub instraction removal tool, Then recrimp the ends of my new cable into the db37 and make the joins at the distributor end with the drain at the ms2. Route the cable away from everything that might cause interference. What is the name of the tool called for crimping the cable to the db37? What size / type of terminals do I need? Thankyou

[rickb794]

Don't invest a lot of effort making it pretty while you are still in the experimental stage.

It's really frustrating when you have to take apart something you spent a lot of time on.

Do test before finalizing your harness, you may need to try the resistor trick.

[frogcow]

Okay I will get back to you with the results.

It looks like another embarrasing error on my part though, when I went to undo the vr cable from the harness I found that I had the shield floating on both ends. I cant get the db37 d-sub removal tool cheap enough here in Australia nor can I get the crimps so I'm going to snip the whole cable and use a db37 with soldered cups instead.