Jump to content
HybridZ
davek

L28ET crank position sensor

Recommended Posts

Received the CAS unit today. Bench test green wire was about the same at 1.3v. White wire was only 0.1 at the high spots.

On the engine it started better. Had to keep my foot on the throttle some to keep it running. Still has a miss but sounds more like one or 2 cylinder missing. Stinks rich.

attached a composite log. What does the log tell us?

I am by myself so couldn't check timing but sounds like way more than timing.

 

It almost would run at idle. Tomorrow or sat I'll get it outside(exhaust reasons). Adjust the butterfly screw or IAC to keep it running. Determine which cylinders are not firing etc.

 

megalogviewer says I need to register to read the full log file. $39.95 I though this license came with tunerstudio registration?

2017-12-21_17.47.47.csv

Share this post


Link to post
Share on other sites

yes

I installed that resistor in MS a few years ago when I assembled MS3X. Instructions were pretty clear now that I reviewed the instructions. I had forgotten this.

Does the log from previous post tell us anything?

Rain the next several days. Rather not work in the rain. Will post more when I get something to share.

Edited by davek

Share this post


Link to post
Share on other sites

latest update

new CAS in the distributor. Started with my foot tweeking the throttle. After is settle down off ASE it would idle.

Adjusted timing to 10 degrees--very steady timing light. Then switch over to the table. Still rough missing idle & exhaust popping.

no sync error but I do have CAM Fault red lght

Composite logged looked very steady.

pulled #6 injector connector(straight 6 engine) and popping stopped. Reconnected injector and pulled #6 COP connecter - popping stopped. No RPM difference either way. Pulled each injector connecters one at a time. #4 makes no change to engine idle.

Swapped #6 & #4 COP to other cylinders. Problem did not follow the COP.

all 6 plugs are filthy black. #4 & 6 are dry as are the others I assume from trying to run the last couple weeks with no success. Changed out all plugs and ran engine for only a couple minutes. All plugs looked new.

Next step is to swap the 2 injectors to other cylinders to see if symptom follows the injectors. Thought process is dirty injectors.

Why a CAM fault??? From reading other posts this fault is not my idle issue. I did start it once today and had no CAM fault. Never had any RPM sync error.

composite log attached

all comments welcome.

Dave

2017-12-26_15.45.59.csv

Share this post


Link to post
Share on other sites

I'm back--- weather returned to normal after low teens.

Pulled #4 &6 injectors and back flushed them then installed in #3&5 position. Problem did not follow the injectors. Aw crap.

 

Rechecked in test mode injector & coils both function. Recheck cylinder compression-OK.

Sill have cam fault light on TS dashboard. Composite log looks perfect. Attached latest data log.

Almost like #6 & 4 timing is off. How can this be?  #1 & #5 plugs look good. #6 is black #4 is not as black.

When pull #6 injector connector the exhaust popping stops and A/F goes full lean. I would expect this. Pull #4 and little A/F change. Neither affects RPM.

running out of things to check!

Any ideas?

What settings do I change to run wasted spark. I look that up & try it. Seems like I tried that this already but may not have had all setting correct.

Dave

2018-01-07_18.34.01.msq

2018-01-07_16.43.32.msl

Share this post


Link to post
Share on other sites
Posted (edited)

I see two " possible "  problems right off the bat. 

 

 Second Trigger Active On is set to  " Rising Edge " .

 

Although DIY recommends  " Poll Level " with MS3 and MS3X,  some people on the MSExtra  Forums report that doesn't work well. You may want to try Falling edge. You may have to re-sync your #1 Tooth Angle. DIY Auto Tuning instructions leave something to be desired. 

 

Use Prediction is set to " No Prediction ".  It should be set to " 1st Deriv Prediction " 

 

Update your MS3 firmware as well. You're running an outdated  format of 0435 .13. Latest Firmware is 1.51 with Signature format 0566.05

Edited by Chickenman

Share this post


Link to post
Share on other sites
Posted (edited)

To change to WasteSpark instead of COP, under Ignition settings Change Number of Coils to " Wastespark ". . I haven't read the whole thread, so what coils setup do you have.  individual COP ( LS style ) or three two coil wasted spark?  

 

Edit: I just went back and loaded your Current Tune from Post #5. In that you were running Wasted COP. 

 

Wasted COP, COP and Watespark are three different setups. Please tell us your Exact ignition setup. With number of coils, or number of Wastespark Coil packs and number of Coil drivers in the MS3X expansion board. .

 

Not very often will anyone run Wasted COP. It's a weird Option only used in special cases. IE:   Six individual coils ( For an L-6 ) , but only 3 Ignition coil drivers. Coils would be wired in matching pairs and fired twice per 720 degrees of crank rotation. 

Edited by Chickenman

Share this post


Link to post
Share on other sites
Posted (edited)
On 12/15/2017 at 5:18 PM, davek said:

WOW

For several thousands of miles I had the black distributor wire grounded to negative battery. MS pin #1 was not used. The distributor has a heavy paper gasket at the base that would not help grounding to the engine but does directly contact the front cover enough for a ground.

I will connect the ground wire to pin #1 per MS wire diagram.

 

as I skimmed the article. I have all grounds going to my fuse panel which has direct ground to the battery terminal. Nothing grounded directly through the engine, frame etc.

1215171915[1].jpg

 

 

That method of grounding can introduce a s**tload of electrical noise into your ECU. Which is exactly what your Datalog is showing. ( I had a quick look at it. ) You have trigger drop outs all over the place.

 

Run ALL of your sensor grounds back to the sensor ground on your MS ECU. Then run the MS ECU ground back to the Intake manifold just like it was done at the factory. The ECU ground MUST not share grounds with any other circuit. Especially DC motors such as Fuel Pumps, Cooling Fans , Defroster motors. DC motors create a ton of electrical noise. That is part of the reason why the ECU is grounded to the Intake Manifold and DC motors are grounded to the Chassis. You want the shortest ground loop possible for the ECU to eliminate electrical noise. 

 

Bus bar grounds are fine for use as a common ground for things like Lights and Motors, but NEVER connect an ECU to one. It's an excellent way to inject a whole lot of noise into the ECU circuit. One sensor grounded to the wrong place, is all it takes to Inject noise into the whole ECU. This was the Mazda Miata screw-up that Andy Wyatt mentioned. The Early Miata's had a Engine coolant temp sensor that was grounded to the chassis. Instead of through the ECU sensor grounds as it should have been. Caused a lot of erratic ECU problems. 

 

The paper gasket under the distributor mount has zero effect. The bolts threading into the  Timing cover complete the secondary CAS ground circuit nicely. As do all bolt threads. 

 

 FSM with wiring diagrams is available for download at: http://www.xenonzcar.com/s130/fsm.html

 

 

 

Edited by Chickenman

Share this post


Link to post
Share on other sites
Posted (edited)

 

 

The ECU main ground should never be mounted anywhere near the starter nor to the Negative battery circuit. The starter motor draws huge current, and is extremely noisy electrically.  It creates large Eddy currents in the engine block  and strong Magnetic fields around it when cranking. This can induce a voltage impedance in ground circuits. Things like lights, solenoids, DC motor aren't affected by this slight voltage impedance in the ground circuit. But the ECU, which has components that operate on Millivolts, can certainly be adversely affected if the ECU ground is connected to the Negative battery cable or any where in close proximity to the starter motor. The Magnetic fields, Eddy currents and Voltage impedance diminish within a certain radius of the starter motor and it's ground wire. 

 

 

 

 

Edited by Chickenman

Share this post


Link to post
Share on other sites
Posted (edited)

Looked at your .MSQ. It would definitely help to Enable " Noise Filtering " under Ignition Settings. Enable both Primary Tach ( Crank ) and Secondary Tach ( Cam ) as you are using both of the Trigger sensors on the CAS.  Use the default settings.

 

Right now you have all noise filtering turned off....  not a good idea. 

 

Edit: Tuner Studio gives unconventional names to things sometimes ( actually, quite often )  And it can confuse people. I Have no Idea why they call these a " Tach " circuit. People immediately think of Tachometer and leave the setting off.

 

What it should be called, and is called by other manufacturers is:  Crank RPM signal ( or Trigger ) and Cam RPM signal ( or Trigger ) . Makes more sense to me at least.... 

Edited by Chickenman

Share this post


Link to post
Share on other sites

One other thing. Check the Trigger wiring to your CAS. On the Factory ECU wiring diagram you can see that all 4 leads for your Trigger wires are shielded.

 

On some of the early MS3 builds, they have the Crank and Trigger wires as a separate 2 x 2 bundle. The Crank signal wires are shielded , but the Cam signal wires are just unshielded twisted pair. They should be shielded as well. All depend on how it was built... but it is something to check. 

Share this post


Link to post
Share on other sites
Posted (edited)

Proper ECU Grounding to the Cylinder head or Intake manifold is clearly recommended by MS as well. Have a look at  section 3.2 " Grounding Schemes " of the MS3 Hardware Manual. Page 13 and 14. In fact, download and read the whole Hardware manual. The Hardware manuals provide the most accurate information for installation, setup and various Option for MS models. 

 

http://www.msextra.com/doc/pdf/html/MS3XV30_Hardware-1.4.pdf/MS3XV30_Hardware-1.4.html

 

Quote

3.2 Grounding (Earthing) Schemes

 Implementing a correct grounding scheme is critical to a successful Megasquirt install. 

Connecting sensors to the wrong ground, using corroded ground points or dubious original wiring are sure-fire 
ways to give you a headache.

There are two key rules:

1. All sensors must ground at the Megasquirt

2. Ground the Megasquirt at the engine block/head using both available ground wires.

Reasoning:

When a current flows through a wire there is always a voltage drop, the bigger the current, the bigger the drop 
(this is ohm's law.) During cranking there is a very large current flowing through the ground strap from battery to 
engine and perhaps a few volts may be dropped across it. Even during running, a number of amps will flow 
through the Megasquirt grounds to the engine. 

The sensors (coolant, air temp, throttle position, wideband, tach input) all use low current, low voltage signals. 
The Megasquirt measures the voltage from the sensor and converts it into a temperature, position etc. reading. 
If that sensor is grounded to anything other than the Megasquirt itself, then that input voltage will be altered by 
any external voltage drops. For a sensitive measurement such as AFR (lambda) this can be a real problem. All 
good wideband controllers offer a high-current ground (connects to engine) and a sensor/signal ground 
(connects to Megasquirt.) 

Tach input (e.g. crank, cam sensors) will be even worse - they can show false or missed teeth and cause sync-
loss due to the ground voltage difference.

The following two diagrams illustrate good and bad wiring schemes showing where the troublesome voltage 
drops are created and how that would cause sensor readings to be garbage.  

 

Quote

If re-using or splicing into OEM wiring, do not assume that their wiring is OK. Always follow the above principles.

As a check, with the Megasquirt connector unplugged, ensure that the sensor grounds have no continuity to 
engine/body ground. Your sensor readings will be junk if they do have continuity - the sensors must ground at 
the Megasquirt only.

 

Edited by Chickenman

Share this post


Link to post
Share on other sites

Turns out the CAS was bad however my main problem was I wired the COP's and the injectors wrong.

I am embarrassed to say.

MS wires are labeled A, B, C, D, E, F and screwed up and wires them to #1, 2, 3 ,4 ,5 ,6 instead of firing order.

Engine runs good now..

 

I still have CAM Fault red light on tunerstidio. Can't find a good answer for that. I also have another wiring problem that I just found. I pulled the fuse that powers MS and the engine still fires up. I'll report back.

Edited by davek

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×