LS1 no trigger

[Ashkelly]

Alright this is driving me nuts.

 

LS1 gen 3 from commodore

in s14 full race car no factory wiring.

motor was seen running in como before pulled.

ECU and loom were running on another car before removed. G4+ xtreme red.

tested spark and fuel and both are happy and operational, no faults on ECU

crank over and no t1 or t2 on scope.

Is setup LS1 5-10 and both hall, 5v on crank t1, 8v on cam t2.

using f12 they both say no, and there is no rpm when cranking or anything on scope.

I changed setting to LS1 3-12 and LS2-LS7, still nothing on scope or f12.

 

Wiring, I have 8v at cam sensor, ground is good, continuity for sensor between ecu and sensor plug is good.

wired in a 3SGE beams cam sensor and changed settings to reluctor. Tested with spanned and F12 says yes but nothing on scope.

I have a brand new Xtreme black I swapped in and put the file on. Still no cigar, nothing changed.

I proved wiring, proved the ECU.

I don’t think both sensors would completely fail at the same time since running fine a month ago.

ive checked plug wiring, and plug and wiring are fine, was on another Como LS1 working fine, plugged straight onto mine.

 

have used multiple battery’s, battery is in boot. Best battery drops to 10.2v when cranking

 

 

[Adamw]

The LS1 sensors are 12v.  They work with 8v, but I would be doubtful of 5v.  Does the Crank sensor have Black or grey plastic housing?  Which pin do you have ground and power on at the sensor plug?

The 3S cam sensor won't work as it needs to be Hall to work with the long 180deg "tooth".

[Ashkelly]

Thanks for the reply, yes someone else I spoke to said they normally wire them to 12v

Yeah unfortunately I didn’t wire it up. Haven’t opened up the loom yet to see where the 5v is feed from.

As well the crank sensor is behind the starter (aftermarket starter relocator) witch is covered by the headers so is a nightmare to get too. Granted I’m in a moon boot nor have a hoist witch doesn’t help either.

as per picture Cam sensor is wired

A sensor T2

B ground

C 8v supply from ecu

 

battery cranking voltage dropping to 10v wouldn’t cause this issue would it?

dumb question but with the 3S sensor and me passing a spacer past it I should be able to see something on the trigger scope window?

 

[Adamw]

9 minutes ago, Ashkelly said:

as per picture Cam sensor is wired

A sensor T2

B ground

C 8v supply from ecu

That would be correct for the Black 24x sensors.  The grey sensors use a different pinout and won't work with the dual row trigger wheel.

 

11 minutes ago, Ashkelly said:

battery cranking voltage dropping to 10v wouldn’t cause this issue would it?

ECU will work down to about 6.5v, and sensors should work down to at least 8v.

 

13 minutes ago, Ashkelly said:

dumb question but with the 3S sensor and me passing a spacer past it I should be able to see something on the trigger scope window?

 

Yes, but you would want someone to click the capture button for you while you do that.  You only get about a half second long capture once you click the button.

[Ashkelly]

21 minutes ago, Adamw said:

That would be correct for the Black 24x sensors.  The grey sensors use a different pinout and won't work with the dual row trigger wheel.

I feel as though this is my issue. Have you got any pin out info handy or where I should look? again thanks for the reply’s, new to LS

[Adamw]

Both pinouts are in the help file, see pic below for navigation.  We label them LS1 and LS2/LS7, but my understanding is that is not quite right and it would be more correct to refer to them as 24X/58X.

I believe all engines LS engines prior to Jan 2006 used what GM call the "24X" trigger system.  This is what we refer to as  "LS1".  The 24X engines should have black sensors, the crank wheel is a weird 2 row, 24 tooth design and the crank sensor actually has two sensor elements inside that combines the two wheels into a single output.  They have a single 360deg long tooth on the cam.  Both crank and cam sensors are powered by 12V on these engines.  I believe some early LS2's for instance use the 24X trigger which is why I say it is not quite correct for us to call it "LS1 trigger".

 

From Jan 2006 onwards all LS engines used the "58X" trigger system.  These engines all have grey sensors as far as I know.  They have a more conventional 60-2 wheel on the crank and a 4 tooth wheel on the cam.  Link refer to this trigger mode as LS2/LS7, but there may be some late LS1 engines that run this set up.  Both crank and cam sensors are powered by 5V on these engines. 

 

 

[Ashkelly]

Can confirm motor has two black triggers. Motors from 2004 commodore

and looking at the sensor socket 8v is on the left side, ground middle, sen right same the photo you posted.

so looking at the loom plug with clip at top it’s, sen left, grd middle and 8v right

LS1 5-10 it’s not seeing anything 

 I changed setting to LS2-LS7 and it did this Tom foolery 

65,500rpm was the highest, not bad for a push rob motor

 

 

[Adamw]

Cam signal looks ok in that scope, but no sign of anything at all from the crank.  It might pay to try it with 12V.

[Ashkelly]

Interesting, managed to get the crank sensor plug off. That too has 8v supplied to it.

why would the ecu say 5v? Is there something in settings I’ve missed?

 

also both triggers have around 40ohms resistance on their centre pins to sensor ground lug..?

[Adamw]

1 hour ago, Ashkelly said:

why would the ecu say 5v?

That is just the pull-up voltage on the trigger pin.  

[Ashkelly]

On 3/28/2021 at 7:43 PM, Adamw said:

That is just the pull-up voltage on the trigger pin.  

Hi Adam

hit a bit of a wall.

Still no luck, have continuity through loom to pins, I have ground, 8v on both, and pull up voltage on both signal pins.

tried xtreme red and black ecu’s with same result.

 

what would be my next step?

[Adamw]

With the sensors removed from the engine, but still plugged into the loom and with ignition on so they are all powered up, back probe the signal pin at the sensor connector and connect a voltmeter (use a paper clip poked through the wire seal).  The signal wire should be 4V or higher with no metal in front of it and 0V when you hold something steel in front of it (like a screw driver or spanner).  If you dont see that voltage change then there is some problem with the wiring/pinout/sensor.

If you see a voltage change at the sensor when you do the above test, then the next step would be to do a similar test using the triggerscope, with metal and no metal in from of both sensors.  If the signal is getting through the loom and back to the ecu correctly then you will have two flat lines on the scope showing 4+V when there is no metal in front of the sensors and flat lines at 0V with metal in front of the sensors.  

[Ashkelly]

Alright sorry late reply been busy with life.

Followed the above and found two issues witch is why I was chasing my tail

so I’ve found crank sensor to be faulty, as both crank and cam plugs had squished sockets making for poor connection.

replaced all of the above and we now have triggers and RPM!

 

when cranking rpm sits around 120-129rpm consistently

however injectors and coils do not operate.

 

I did some Tom foolery while I had the old sensor out witch gave wild rpm and the injectors and coils started operating so I know their good.

 

have I missed something?

battery’s is well charged and near zero drop in voltage at ecu and sensors when cranking.

does take a second or two for triggers to sync and ready RPM

 

cheerS in advance 

[Adamw]

Do you hear the injectors click and do the coils spark if you use the injector/igniton test function?

Can you attach a log of it cranking and the tune.

[Ashkelly]

Thanks for the quick response.

When sensor was out and tapping with spanned yes could hear injectors working.

 

new sensor and everything plugged in, can’t hear injectors nor can I smell fuel at TB while holding it open.

yes test function for both coils and injectors work fine. I even cycl though all of them to make sure no cyl runs rich or lean after start up.

No errors showing.

Will post file in the morning

[Ashkelly]

REUBENS LINK update.pclr crank log.llg

[Adamw]

Either your MAP sensor calibration or wiring is wrong, it is showing 166kpa all the time which is above your MAP limit, so you have a 100% fuel cut.

[Ashkelly]

Thanks Adam set it up on cal4 and red labels are gone

went to crank and received this 

 

is setup with can WB and dash but currently are t powered if that would cause an issue?

excuse the ignorance I’ve only had a plug in and base map setup before 

[Adamw]

Not sure what your concern is, nothing much wrong in that video.  The value that a parameter changes to orange or red at is user configurable.  By default they are set to values that will suit most applications, but not all.   

It took quite a while to display RPM, but it looked realistic.  Have you tried a squirt of starter fluid while cranking to confirm there is fuel in there?

[Ashkelly]

Yeah I did the injector test function with all to get a bit in each port, could smell fuel in the throttle body

when cranking we can’t hear the injectors going though, funnily when we stop cranking we can hear them going for half a second then stopping as the motor comes to a stop

[Adamw]

Even if you are sure there is fuel, it is always a valuable test to try a shot of starter fluid so you can eliminate any fuel related issue off the list of possibilities.  I cant tell you how many times I hear "fuel is fine", only to find the fuel pressure reg hooked up backwards or something stupid.  Stale fuel, stuck injector, not enough PW, not enough fuel Press, no voltage at injector when cranking, etc...  All things that can quickly be eliminated with an alternative fuel source.  

If still no signs of life with a squirt of starter fluid then you start looking closer at spark, compression, cam timing, air flow etc, all much more complicated things to verify...

[Ashkelly]

Thanks

 

yeah I’m concerned I can’t hear the injectors when cranking.

yet when cranking it says injector PW is there....?

 

might pull the lines off the reg as well to makes sure witch ports holding pressure like you said. Gauge says around 65psi and hear the pump building pressure so I know one sides doing something it should.

as well I’ll chuck some more fresh fuel in it.

 

cheers for reply’s, will run through above Thursday evening and let you know how we get on

[Ashkelly]

Update..

 

it lives!!

multitude of issues

faulty crank sensor

worn out trigger plugs

MAP sensor wired wrong way around (apparently different bosch sensors have the sen & supply swapped)

dodgy grounds

weird ecu setting with wild fuel master

i was a dickhead and changed ign/fuel output to high for testing and forgot..

 

the list goes on...

 

anyway, thank you for the reply’s and support! Has been a good learning curve

Ash

[Ashkelly]

Hi, I’ve lost triggers again.

 

car ran fine, went and got tuned, did two track days and now will not start.

 

before tune both sensors were replaced and both plugs changed for new plugs.

 

tuner didn’t see and trigger issues and no faults are logged on the ecu.

 

currently have live ECU, 8v supply at both plugs, when cranking battery drops to 9.4v but ecu stays on and stays connected to laptop.

there is no trigger activity on either triggers on the tuning trigger window.

 

nothing has been unplugged, the car has not been touched since it drove off the trailer a month ago. Have tried different battery’s and both have been on charge.

what would next course of action be?

Both plugs and sensors have been replaced so surely it’s not those again??

[Adamw]

If the trigger scope shows no signal and the ecu shows no rpm then there is no signal being received.  It could be wiring or the sensors, but I would say unlikely both sensors failed at the same time.