Jump to content
HybridZ

Timing control problems


baggedgoods

Recommended Posts

Ok, thank you for clearing things up. Now, while using my stock ignitor, the car runs but really poorly. I'm still not able to control the timing besides rotating the distributor. What would the issue be if not my settings in MS? To get spark, pin 36 needs to be wired in to the signal wire on my stock ignitor(since I don't have the BIP373 ignitor)

The issue might be the stock ECU.  No one is going to be able to help you until you eliminate that from your car.  There is no reason to keep it.  I doubt anyone knows exactly what the stock ECU is doing and no one is going to do the research to figure it out so that you can run a weird piggybacked setup.  Check if your MSII has a BIP373 like Chickenman explained and if it doesn't (which I bet it doesn't) then buy one and install it. 

 

 

 Are you absolutely sure you don't have a BIP373 driver? They are internal and are built onto the MS Mother Board.  

 

I assumed he doesn't because if you look at the pre-assembled MSII product page it says this

 

 

"Slot for installing a BIP373 (not included) for direct coil control"

 

https://www.diyautotune.com/product/megasquirt-ii-ems-system-smd-pcb3-57-assembled-ecu/

 

 

 

The other question I have, and this is directed to anyone who has used MS while staying with a single coil and distributor.  Can MS even adjust timing?  Wouldn't you set timing and lock it and then allow the distributor advance to control timing?  I would think the timing is essentially set by the rotor and cap, but then again I opted to go wasted spark when setting up MS on my car so I don't have any experience with it. 

Link to comment
Share on other sites

  • Replies 73
  • Created
  • Last Reply

Top Posters In This Topic

 

 

 Can MS even adjust timing?

The answer is Yes. Just like any other ECU that controls ignition timing. They all use the same principles.

 

When using Electronic Timing control, there are no mechanical or Vacuum advance units built into the Dizzy. The rotor is fixed solidly to a shaft and always stays locked to the same position, relative to the crankshaft. 

 

There are no mechanical advance mechanisms inside the Nissan CAS dizzy's. MS adjusts timing electronically just like the factory ECU.  The design of the rotor tip ( any Dizzy rotor tip )  is in an arc, and allows it to direct the spark to the correct terminal over a fairly large range of timing variation.

 

Technically, Electronic timing control is done by retard only. That's why you have a trigger offset of 50 to 70 degrees. IE: Trigger offset 60 degrees, actual trigger signal is at 60 degrees BTDC.  To get the spark at 10 degrees BTDC, the ECU simply delays or retards the output signal for a time period that equals 50 degrees of crank rotation.  The ECU is constantly adjusting the output delay value from the Input trigger signal to give the amount of spark BTDC or after TDC.

 

The Trigger offset must always be higher than what the maximum spark advance the engine requires will ever be. ( At cruise some engines will tolerate 45 to 50  degrees of total advance. Low mixture density and lean mixtures contribute to a very slow combustion burn ).

 

Edit: Wasted spark and individual coils are all done the same way.

 

Old style Dizzy's with mechanical advance and  vacuum pots physically moved the Trigger point with a rotating breaker plate. So the Trigger point starts off low, lets say 0 degrees BTDC. Then the mechanical and vacuum advance mechanisms physically rotates the Trigger device ( points or sensor )  and advances it's position. If you've worked on old time dizzy's you remember how to check to see if the advance mechanism is working properly If the rotor turns clockwise, you grabbed it and see if you can twist it counter-clockwise with no sticking. Then you released it and the rotor should snap back to the original position. That's the trigger point being moved mechanically by cams and weights etc. You actually do add timing with the old mechanical and vacuum methods. 

 

ECU timing control is done with a fixed Trigger point and then timing is subtracted from that point by electronic delay. The dizzy in an ECU controlled timing system ( any make )  is only used to send the spark to the correct cylinder via the rotor and terminals. This allows the use of a single coil. Distributor less systems, ( Waste Spark or COP ) just have multiple coils. The spark timing is still delayed fro the Trigger point, just like in the  CAS type of Dizzy. 

Edited by Chickenman
Link to comment
Share on other sites

Makes sense.  I just looked at a picture of the rotor and it looks like it would give about 35 degrees of retard if setup properly.  I wonder if between the stock ECU and MS, it is trying to adjust the timing outside that range (either due to distributor being clocked incorrectly, or improper total timing adjustment in MS/Stock ECU) causing it to attempt to fire the coil with no flowpath.  That would cause sporadic ignition timing and therefore sporadic RPM readings. 

Link to comment
Share on other sites

Oh.. I think there are a lot of things that could be causing the sporadic readings. Trigger wires are particularly sensitive to EMI.

  • Grounds MUST be in specific locations as per the ECU ( in this case MS ) instructions.
  • The Trigger wires must be shielded or have twisted pair wires. Often they have both. You can not run Trigger wires near any High Tension ( Spark plug or coil ) leads or near the Ignition coil. Trigger wires should not be run close to +12V leads
  • NEVER mount an ECU close to an Ignition Box, CDI Box or Ignition Module. Ignition boxes and modules create a ton of EMI. Look at the Factory ECU and Trignition Unit on a 280Z. ECU is in drivers footwell. Trignition Unit is in passengers footwell. That's all to eliminate EMI interference. You want the same type of separation with CDI Boxes. 3 feet minimum.
  • You must run resistor leads or preferably spiral core HT Leads. Never run " old school " solid core stranded HT Leads. You must run resister plugs. failure to do so will create a lot of EMI and create Trigger noise.

The OP has a very steep learning curve ahead of him. The devil is in the details. Instructions must be followed to the letter. The slightest setting wrong, poor grounds, Ground Loops ( many people don't understand those ),  or instruction not followed to the letter, will cause you grief with electronics.  All I can say is Read, Read and Read some more. You really should have a good understanding of Electronics before trying to build any stand alone system. Hands on experience of building circuit boards and repairing electronic devices really helps. 

Edited by Chickenman
Link to comment
Share on other sites

Here is the FSM for my car. Obviously you guys probably have access to this but this'll help me help you guys see what I'm working with.

 

I'm sure I can just get rid of my entire stock ECU but I'm not 100% on what I would do with some things that I believe I'll need. I'll make a list.

 

Pressure Regulator Control Module

Cylinder Head Temp Sensor

Detonation Sensor

Vehicle Speed Sensor

EFI Relay?

 

I'm sure I can find everything I need to know about this with some digging but I was hoping you guys might be able to point me in the right direction. And yes, I'm aware that this has nothing to do with the original post but this will lead to either a win or another headache regarding my ignition and timing.

post-52146-0-82278000-1490977925_thumb.jpg

Edited by baggedgoods
Link to comment
Share on other sites

^ MS 2 can control all of those functions itself.

 

Relays are the simplest parts. EFI relay is just the fuel pump relay. Cylinder Head Temp sensor is not really necessary. You use the Coolant Temp Sensor instead. Vehicle Speed sensor. Not really required but MS can handle it . Pressure Regulator Control Valve is your Electronic Boost control valve. It's a simple Pulse Width Modulated solenoid and again, MS can handle it. You can also  use an aftermarket Electronic Boost controller or Manual Boost controller to adjust boost.  Detonation sensor is just a Knock sensor and MS can handle it. 

 

The real trouble is I think you ar in way over your head. All of these functions you should have known about and should have had some working knowledge of how they operate before you got into this process. . You really should be asking for advice on MS/Extra forums. That is where the real experts like Matt Cramer reside. They also have a Tuner " location " forum where you can see if any Tuners or Members with experience live near you.   Then they can come over and have a hands on look at your system.  Sometimes money is exchanged. Sometimes Beer and Pizza. 

 

Standalone systems, particularly on Turbo cars , are not something a Noobie should get them selves into. No offense meant. But it's so easy to melt down a Turbo engine with just a single wrong setting. Tony D and myself agree. If you have a big $$S Turbo engine built with all the fancy pistons, rods, heads etc. It's better to let that big $$$ engine sit on an engine stand and buy a couple of Junk Yard " Mule engines "  or at at least short blocks. Cause you're gonna melt one or two down when you make a mistake. And you will make mistakes. Sacrifice the JY short block to the Gods of Detonation while you learn to tune. Again no offense. Justs some sound advice. 

 

Here's a link to the MS/Extra forums. I would advise going there, registering and start reading and asking questions there. Everything, and I mean everything is covered there somewhere. Read, Read and Read some more.

 

http://www.msextra.com/forums/index.php?sid=ccfe77dd9149308893877abac105345f

 

Here's the link to the " Find a Tuner/Member page. Find someone good in your area and stock up on Beer and Pizza. 

 

http://www.msextra.com/forums/viewforum.php?f=137

 

Tuning and knowledge wise, you are basically at Baby steps right now. Tuning s high boost Turbo engine is the equivalent of an Olympic runner. It's not something that is gonna happen overnight. Good Luck. 

Edited by Chickenman
Link to comment
Share on other sites

Another couple of links. Consider joining the " Guild of EFI Tuners " on FB. This is the FB page for High Performance Academy.  A well respected tuning company in New Zealand.

 

They are generally an advanced group, so I would advise just lurking and absorbing information for a while. They have free Web Seminars where they explain how to tune various aspects of EFI. A lot of info there for both the Noobie and advanced Tuner. Some of their seminars are free, but they also have Paid subscriptions suitable for Professionals who Tune cars for a living. 

 

FB Link for Guild of EFI Tuners: https://www.facebook.com/groups/737420992943719/

 

Link to free web seminars at Horse Power Academy. You may have to Register ( Free ) to access these videos and join the notification group for up coming Web Seminars. 

 

https://www.hpacademy.com/webinars/

 

Edit: Do your have the Tuning book from DIYAutoTune? If not get it ASAP:

 

https://www.diyautotune.com/shop/apparel-merchandise/books/

 

book-hp1557-600x600.jpg

Edited by Chickenman
Link to comment
Share on other sites

The following link should be Bookmarked and read several times. It addresses the issues of proper grounding procedures and how common grounding mistakes can cause, sensor deviations, noisy Trigger signals and even inadvertent Ignition coil discharges ( Part of the LS2/Yukon Coil self-discharge problem ).

 

http://www.adaptronic.com.au/ecu-grounding-tips/ 

 

Grounding locations are EXTREMELY important with ECU's. Star grounding, all grounds located at a single point is critical. 

 

Nissan CAS systems are very specific to the ground location, due to the Dizzy body being bolted to the engine and the CAS ground being connected to the Dizzy body. Those all grounds from the ECU should be bolted to a Star point mounted on the engine. Not to the Chassis or Battery negative terminal. Otherwise you induce voltage offsets and noise. 

 

 

 

If the sensor’s ground is not isolated from the body of the sensor and it has to screw onto the engine, for example many Nissan cam angle sensors, narrowband oxygen sensors and many knock sensors, then you don’t have a choice; you have to choose the star point ground at the engine. Because the engine is so thick and low resistance, the actual point on the engine doesn’t matter too much; but often this point is on the inlet manifold or cylinder head on production cars.
Edited by Chickenman
Link to comment
Share on other sites

From the same Adaptronic article. The last Paragraph is extremely important:

 

 

As mentioned earlier noise getting into crank angle sensor wiring and causing triggering problems. Firstly, this can often be misdiagnosed because it’s a complex interaction. As the load on an engine is increased, the ignition system generates more noise, because it requires a higher voltage to ionize the higher pressure air in the cylinder. This noise can then get into the trigger input. So although it’s a trigger problem, it is load dependent. And although it’s a trigger problem, it’s caused by the ignition system. So the fact that a misfire is load dependent does not rule out a trigger problem, but at the same time changing the ignition system may not fix the problem.

Also, they say that there’s no shortage of advice online but there’s a shortage of good advice. We’ve seen people say that “you should rerun your crank angle sensors with really good shielding and that will help keep out the ignition noise”. If the shield is copper or aluminium, it’s not going to do anything to the magnetic interference because those metals are not magnetic. So although people say to do it, my first recommendation would be to check that the ignition loop current area is as small as you can make it. If we’ll look at any OEM ignition system, we will see that’s exactly what they’ve done.

There are other factors that will influence the amount of magnetic noise that a system generates. Running non-resistor plugs will generate more noise than resistor plugs. Running solid leads will generate more noise than resistor leads. Higher boost / load will generate more noise. Larger gap will generate more noise for the same reason.

Finally, most ECUs allow changes to the amount of filtering and voltage thresholds for the crank and cam sensor inputs, so in many cases you can filter out the noise anyway. In some cases it just won’t be possible though and it depends on signal to noise ratio. This is one reason I really like reluctor sensors over Hall effect; the voltage of the sensor increases with RPM, and generally if there’s going to be a trigger problem it’s going to be when the engine is at mid to high RPM anyway, so the reluctor sensor gives you a much higher signal to noise ratio than Hall effect.

So, now to the punchline. Because we are going to use star earthing, we need to pick a point for it. Because the coils need to be grounded to the engine to keep the loop area small, that means that the star point has to be the engine. This also conveniently works for some sensors whose output is not isolated from the chassis, for example many Nissan cam sensors. And if you look at almost any OEM installation, they ground the ECU to the engine.

Thank you and happy learning!

Link to comment
Share on other sites

  • 2 weeks later...

Why would I be running my tach signal through the VR conditioner to use the drop in trigger wheel? TunerStudios seems to be reading the rpms just fine with the 12-1 trigger wheel without me even having to open the MS case. I will go in and change things around if it's absolutely necessary. I've been through the MegaManual also, and that doesn't seem to have helped me figure this out. Now if I do need to bring everything through the VR conditioner, would I need to do everything else that I have highlighted red? I will probably end up just running single coil or wasted spark (no sequential COP or sequential fuel)

Thanks guys.

Hardware mods – V3.57

  • For a V3.57, you’d have to remove a lot of parts to use the Hall / optical input, so we’ll just bring this in through the VR conditioner instead.
  • Place the JP1 jumper in the 1-2 position.
  • Place the J1 jumper in the 5-6 position.
  • Put a 1K resistor in the R57 slot (Or you can use a 1K pull up in the wiring, as above.).
  • If you want sequential coil on plug (or sequential injection with the 3.2.1 code), you’ll also need a second trigger input. Solder a 1K resistor onto a length of wire, and cover the resistor with heat shrink tubing. Connect this resistor-on-a-wire combination from JS10 to SPR1. You could also use PAD7 if you’d rather bring the input in through the DB15.
  • Solder a 470 ohm resistor onto a length of wire and cover with heat shrink tubing. Run this resistor-on-a-wire from the 5 volt terminal in the proto area to SPR1 (or PAD7 if you used this in the preceeding step.).
  • Connect a 0.1 uF capacitor from JS10 to SG or the proto area ground.
  • Install the spark output of your choice. BIP373 or QuadSpark output mods are two possible choices. OEM Nissan SR20DET ignition modules require 5 volt logic level ignition outputs.
Edited by baggedgoods
Link to comment
Share on other sites

I think you should stay away from sequential right now . It's more learning for not much gain. Find some easy way to get your timing right by using MS only and go from there.

Right. That just seems like a whole lot more work for a small potential gain. My ms2 v3.57 board isn't wired to use the optical sensor, but it's wired through the vr conditioner. (I believe) If TS is getting an rpm signal but not controlling timing, could the board be wired wrong for the ignout? Or tachout? I'm thinking of the J1 jumper correct?

Link to comment
Share on other sites

I'm a little lost as to how to wire up the BIP373 on the 3.57 board. DIY says to jumper js10(from the center hole of q16) to IGBT IN. Other sources say to connect pin1 on the bip to the spark a output on pin 7 of the u1 circuit. And the 3rd pin to ground.

So it would go which way
BIP#1->spark a at pin7 of u1
BIP#2->center hole of q16
BIP#3->ground

Or

BIP#1->?
BIP#2->center hole q16
BIP#3->ground
JS10 jumped to IGBT IN instead of center hole to q16

Link to comment
Share on other sites

PM answered. Basically... follow the latest DIY instructions and run the latest firmware.

 

There are various ways to build these boards and Board model, way board was built and Firmware version all have to match. You have to be careful when reading information from older posts because there are build revisions and firmware updates fairly often with MS. 

Link to comment
Share on other sites

PM answered. Basically... follow the latest DIY instructions and run the latest firmware.

 

There are various ways to build these boards and Board model, way board was built and Firmware version all have to match. You have to be careful when reading information from older posts because there are build revisions and firmware updates fairly often with MS. 

Yeah, I understand that. The firmware for the board is 3.3.0. I know at msextra, they say to run the new 3.4 firmware, but I'm a little skeptical doing that right now. I'm going to get the car going with the firmware already on the board. I wish they would update the links to some things because some of them take you to the Megamanual still or older posts from like 2009.

Link to comment
Share on other sites

Well, good news is that it's starting to get nice outside! Bad news is, I'm not getting spark. I wired up the bip373. I have js10 jumpered to igbtin. Js10 was previously jumpered to center hole of q16.

 

Weird thing was, I got spark with setting d14 as my spark output in tunerstudios when clearly js10 should have been the setting. I've completely gotten rid of the factory ecu and wiring. MS is basically the only wiring in the engine bay. I've got 12 volt to the + side of my coil and pin36 to the - side. I've wired up my injectors/fan/coil to a fuse box wired to a relay back to a switch inside the car. It's been nothing but an uphill battle with this.

Link to comment
Share on other sites

Ok I didnt read the whole thread just here and there.

If your not getting spark but did before its most likey some recent changes you made. However, I belive you need to take a second look at you cas wiring. You mentioned some factory wires still running there. I would look there and run fresh new wire all the way to ecu. 12v switched, signal from.pin 24 I believe off the top of my head needs to come from ecu and 12v switched feeding into it with 1/4 resistor between. and ground to engine.

Link to comment
Share on other sites

Ok I didnt read the whole thread just here and there.

If your not getting spark but did before its most likey some recent changes you made. However, I belive you need to take a second look at you cas wiring. You mentioned some factory wires still running there. I would look there and run fresh new wire all the way to ecu. 12v switched, signal from.pin 24 I believe off the top of my head needs to come from ecu and 12v switched feeding into it with 1/4 resistor between. and ground to engine.

 

I have the cas wired as followed: 12v with 1/4 resitor. Pin 24 to signal. Ground back to megasquirt(wire is within shielded wire). All I have changed was getting rid of my external stock power transistor and am now running a BIP373 solder onto the heat sink at Q16. JS10 was wired to the center hole of Q16, yet I'm 90% sure that it fired with D14. Which wouldn't make sense. Now JS10 is jumpered to IGBTin to supply the ignition for the bip out of pin 36. I also played with the J1 and JP1 jumpers but I put them back to how they were before I opened the board. Opto-in & Opto-out.

Edited by baggedgoods
Link to comment
Share on other sites

Check your Tacho configuration and other Pinouts. Make sure that JS10 is not used for two different things.

 

If that is not the problem, try it on D14 again. If you get a good spark and can control timing don't worry too much about it. Probably a board configuration isse. 

 

Edit: You should also upgrade your MSExtra firmware to 3.4.2 as previously mentioned.  Your current firmware is pretty old. 3.4.2 has been out for some time and is stable. 

Edited by Chickenman
Link to comment
Share on other sites

Check your Tacho configuration and other Pinouts. Make sure that JS10 is not used for two different things.

 

If that is not the problem, try it on D14 again. If you get a good spark and can control timing don't worry too much about it. Probably a board configuration isse.

 

Edit: You should also upgrade your MSExtra firmware to 3.4.2 as previously mentioned. Your current firmware is pretty old. 3.4.2 has been out for some time and is stable.

I have looked around and haven't seen any configuration. I know that if I turn on tacho output, I get a configuration error because it is set for js10 when on. And i have tried changing it to d14 but I still get nothing.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...