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altezza troubleshooting


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hey guys I'm a little stumped, for some unknown reason my injectors and coils stopped firing ( some down time for maintaining the car, I know I put the car back together as it was before, I get injector signal and spark when using the stock ECU so I know its not a forgotten clip/ anything from maintaining the car.)

my cam position sensor and crank position sensor are being read by my Link so no issues there as far as I can tell, I re-uploaded my tune and tried the link supplied Altezza base map still no luck getting injector pulse/spark . 

After posting on the Facebook Link support page I took the advice of some guys and lowered my first Three  Trigger 1 aiming threshold values     

 0 RPM= 0.2v    1000RPM=0.3v      2000RPM=2.0v  

After doing so I did get my injector pulse and ignition, the car starts and will idle for a few minuets. I'm still looking for the root cause of my issues as I shouldn't have to change a known working tune. 

Any advice would be greatly appreciated 


unkown 02.llg Trigger Scope Log 2020-08-15 5;18;36 pm.llg OG tune.pclr

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Sorry for the slow reply.  

There's definitely still trigger issues in your log - it looks like once every couple of revolutions it looses sync but I dont see an obvious reason for it.

Can you try adjusting both trigger 1 and 2 arming threshold tables to match my examples below.   If that doesnt help can you do a few more triggerscopes at different times - say 5 or so.  If it is caused by an intermittent connection or noise etc we will have a better chance of catching it.


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Ok, all the triggerscope captures actually look ok but the logs still show many trigger errors.  The only hint that something is wrong in the triggerscope is trigger 1 is much lower voltage than usual and only about 1/6 of trigger 2 voltage.  Usually on these engines they are about the same or trig is much higher than trig 2.  

So Im suspicious there maybe something like a ground missing from trigger 1.  I have had a case before with a disconnected ground which gave a similar scenario - there was just enough current passing through the circuit to show a waveform on the triggerscope, but not enough grunt to get through the VR conditioner and other processing electronics before the main processor.  

Can you unplug the crank sensor and measure resistance between the ground wire at the crank sensor plug and to say some other known good sensor ground such as at your TPS plug or even back to the ecu pin B17

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hey, i added a new engine ground and took some new scopes, I also to a data log as it randomly started hunting for idle and stalled 

new ground scope 1.llg new ground scope 2.llg new ground scope 3.llg new ground scope 4.llg new ground scope 5.llg new ground scope huntimng.llg new ground scope hunting 2.llg stall log.llg

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No, no different, still major trigger issues and voltage hasnt changed.


1 hour ago, Mexi193 said:

if i am correct in locating B17 then my resistance is 1.232 ish K ohms 

  Sorry I just noticed it is "O17" in the manual.  Provided you were checking the correct pin you should see something close to 0ohms.  Can you check again resistance from crank sensor ground pin to ECU O17 and O24.



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Ok pin 17 bounces around 5M ohms to 2.75 M ohms 

pin 24 is 0 to .5 ohms 


I originally had the wrong pin 17

i did also add a new engine to chassis ground after testing the wrong pin 17 a few hours ago  

 I found one pin put but it says pin 16 is the cam position sensor and that just gave me 1.477 K ohms 


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Im starting to run out of ideas.  0.5ohm to pin 24 suggests the ground is ok.  

With ecu plugged in, but crank sensor unplugged, can you measure resistance between the crank sensor ground pin (in the eng loom) and a clean ground point on the engine block/head.

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Ok, Im clutching at straws now, cant really see much wrong.  

Try this:

Save a copy of your map.  Change trigger mode to something completely different - say chev LS1 or something.  Do a store.  Then load your saved map back in.  This will completely overwrite and re-initialise all trigger settings - just in case one of the hidden settings that we dont see has become corrupt somehow.

Do another idle log after that.

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ok so tonight I ended up changing out my cam position sensor for one of my spares also changed the trigger setting to an LS (saved that as well)  before reloading my tune 

I'm for sure still having an issue with the car drooping out of sync with the cam position sensor ever few revelations... 

new cps data log.llg new cps scope 1.llg new cps scope 2.llg new cps scope 3.llg new cps scope 4.llg

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ok I have updated my trig 1 as above. things seem to be a lot more stable. 

I've also swapped cam and crank sensors before updating trig 1 and it made no change in how the car "ran" 


I checked for resistance on the crank sensor plug,  if go from the black white wire to pin B-16 I get .5 - 1.00 ohms with the ecu unplugging. 

and then for the blue wire in the connector I went from the harness connector to the valve cover I get 0-.5 ohms when the ecu is plugged in and no response when the ecu is unplugged   
(Pin out used is the one I sent previously.)  

trig 1 update scope 1.llg trig 1 update scope 2.llg trig 1 update scope 3.llg trig 1 update scope 4.llg trig 1 update scope 5.llg trig 1 update log 1.llg


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So it appears it is running fine in that log.  So the question is why has the voltage from your crank sensor reduced so much...  Wiring sounds ok from the tests you have done so far.  Is it possible the sensor air gap has changed?  Did you have any of the front of the crank shaft/pulley/oilpump apart when you were doing work on it?  Can you do a rough crankshaft end float check with a pry bar or similar and check the crank doesnt float backwards/forwards.

Can you also measure resistance between the black/blue wires with ECU unplugged.  It should be mega ohms or open circuit.

Can you do a trigger scope at around 3000RPM and another at around 4-5000RPM and we will check the voltages at higher RPM too.

So it should be fine to run it like this - it is just odd for it to change on its own.

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hey, so the crank sensor has a fixed location with no wiggle room to allow me to move it closer or further away from the tone ring, the tone ring appear to be in perfect condition. I did remove the timing belt to reseal my water pump I didn't  have to remove the crank gear/ tone ring  or oil pump all went untouched, i also checked for "crank walk" and I didn't get the crank to move forward or backward with a prybar. 

 from blue wire to valve cover with ecu unplugged the multi meter doesn't change from the default screen with ecu plugged in I get  between .5 - 1.1 ohms  

Black/white to valve cover  unplugged no change from default screen on the multi meter, pugged in I got a reading of 53.5 k Ohms (i can only assume this is from running though the ecu?)

I agree it seems very odd to have such a big drop in voltage, i must be missing something I've done ? Unless it’s an ecu issue? Which I could see being an issue the wiring check out the sensors on sit in one location and the stock ecu can still read the sensors with no issues.   

scope 3500ish.llg scope 5000ish.llg scope 5000ish #2.llg

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Set the trigger 1 arming threshold to the example below and see how it runs.  I suspect it will be fine.



22 hours ago, Mexi193 said:

Would the next logical step be to send the ecu into link ?

You are welcome to, but there are not many explanations I could come up with for an internal problem to cause reduced voltage reaching the trigger scope and micro.  The triggerscope hardware and the micro that runs the engine are separate pieces of hardware so when both show symptoms of low voltage then it generally suggests there actually is low voltage. 

The issue is if you send it back and we find no problem you will be charged for the service and shipping.  I think a more logical next step would be to find someone locally with a standalone oscilloscope to do a capture - if that standalone scope shows a similar low voltage to the built-in scope then the problem is external - if it however shows a voltage on trig 1 more like your cam sensor (12-20V) then you could conclude it is likely internal and will be a warranty repair.   

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