Trigger error help

[Fintank11]

Hi All, 

I had my engine running and started every time no trigger error etc. I had to remove the timing casing to fix a leak and I fitted a new cosworth vr crank sensor as it had a few cuts on cable. Car now won’t start and I’m getting trigger error warning and engine speed roc is going as low as -8000. I also have no spark when cranking but i have spark during test function.  I will attach a log file in a few minutes, just wanted to post up and see if anyone has any ideas.

 

car is a 1997 Nissan Micra 4 cylinder

36-1 trigger wheel

cosworth vr sensor

honda k20 coils 

thanks 

[DerekAE86]

Make sure to attach the trigger scope log as well.

If nothing but the sensor was changed it seems to point directly to that. Could be that the gap between the sensor and wheel teeth isnt set correctly, the new sensor isnt the same style as the old one or it's just dead.

[Fintank11]

@DerekAE86 I have the old sensor back in. From jacking the engine up and down etc the crank sensor bracket was rubbing the chassis leg. I dont think its bent as the sensor is still aligned perfect with teeth. is the crank scope the capture function?

01.09.23.llgx

[DerekAE86]

10 minutes ago, Fintank11 said:

From jacking the engine up and down etc the crank sensor bracket was rubbing the chassis leg.

Err that doesn't sound good. 

10 minutes ago, Fintank11 said:

is the crank scope the capture function?

Go to ECU Controls -> Trigger Scope and record a log via this setting of cranking the engine (start recording before cranking and end recording after cranking has stopped)

[Fintank11]

@DerekAE86 I will do this tomorrow morning.  Just a few other details to help aid. I only have the shield wire earthed at the cylinder head right beside the plug for crank sensor which loom is about 150mm long which has no shield from ecu, does it need to be earthed to a ground at ecu and closer to sensor ?And I also have the trigger wiring beside the alternator wiring would this cause a noise effect ? I have the alternator removed in logging to check if it was causing it.

 

thanks 

[DerekAE86]

This is sounding like a lot more than you just changing a sensor.

It is very important the air gap between the VR sensor and the teeth on the trigger wheel is correct.
If the bracket has been hitting the chassis its possible the gap is now out of spec which means it won't reliably detect the teeth.

As far as shielding - it should not be grounded at the engine.
The shield should join the trig -ve wire, connect to the sensor ground pin at the ECU end and extend the full length of the loom as per the instructions:

[Fintank11]

@DerekAE86 it’s just odd as the wiring all worked prior to removal and swapping sensor. I get that the bracket may have moved and my air gap may be too big now but I straightened it and still the same. I will rewire the shield wiring as soon as i can.

 

 

what causes the roc speed to go negative ?

and would the incorrect trigger signal cause my no ignition on crank issue?

 

thanks

[DerekAE86]

You'll have to do a Trigger Scope to really tell. But I suspect the ECU is only seeing a very intermittent trigger signal so sometimes RPM is detected and then suddenly no RPM. That would cause the ROC to go negative (Cranking RPM -> 0 RPM).

And yes, without an accurate trigger signal the ECU can't tell where in the rotation the engine is so won't spark until it can figure that out.

[Fintank11]

@DerekAE86 I got the engine running again it just needed adjusting. I will rewire it the way you have stated though. Just one last thing , I have a 10bar link ecu oil pressure sensor and I’m trying to calibrate it but there is no option for a link 10 bar sensor in the list. Please see attached if you know which one I should choose. My link options only go up to 6.5 bar.

thanks

 

@DerekAE86

[DerekAE86]

1000 kPa (150 PSI) TI Sensor 

[Fintank11]

@DerekAE86 with that calibration it reads 90-100 psi on a fresh rebuild cold. I thought it had the wrong calibration. Engine is cold though and will need to get to temp to drop down pressure. I will try run the engine up to temp under this calibration and see what pressure it reads.  
 

thanks

[DerekAE86]

100psi of oil pressure at idle? What does it read with the engine off?

[Fintank11]

@DerekAE86 0 psi with engine off. When cranking with injectors etc turned off it’s 32 psi. When first started it was at 100 dropped to 90 after 10 seconds. This engine doesn’t run for any longer than 10-15 seconds. The car cuts out due to when lambda activates the afr shoots up to 22afr and it kills the engine. There’s no base map for the Nissan Micra/March so I’ve been using a 4age map just to get it started. Been working through getting all the sensors working which I have done so.   Car is booked for mapping in 2weeks so trying to make sure I’ve everything working prior to going.

[DerekAE86]

It's not that the Lambda sensor activating and reading 22AFR is killing the engine.

During cranking and just after crank there are Enrichment settings which put in more fuel to get the engine started and idling when cold.
But when that decays off it will fall back on the main Fuel Table which is obviously currently far too lean and the engine stalls because of the lack of fuel.

It just so happens that the Lambda sensor has a start up delay that lines up with this happening.

If you're on Modelled fueling (which you really should be using) and all engine/injector data is correct putting 50% in the Fuel Table at all the idle range cells should allow the engine to idle and then you can decrease/increase as required once the Lambda sensor activates and reports if its still too lean or now too rich.

51 minutes ago, Fintank11 said:

0 psi with engine off. When cranking with injectors etc turned off it’s 32 psi. When first started it was at 100 dropped to 90 after 10 seconds.

Are you sure it's reading PSI and not kPa? And are you sure it was a 10 Bar sensor in the box? (What does it say on the sensor label?)

[Fintank11]

@DerekAE86 will try the 50% across the idle range and see if it will idle for longer.

 

I will check the sensor tomorrow to make sure it is definitely a 150 psi 10bar sensor. 
 

thanks

[Fintank11]

@DerekAE86 ok so I set the fuel around idle rpm to 50% and my afr is 12.4 and engine idles no problem now. Fuel ratio may need to be highered to get 14.7 though. What do you think ? When I Rev the car it revs it self up over 2k still. I’ve a new tps sensor on order as my current one has a rattle inside which I hope will fix this issue.

 

As for the oil pressure, I set it to the 150psi and is showing 90 psi on idle at 50 degree engine temp (didn’t want to let it go higher incase of damage) when I set the calibration to 6.5 bar link it idles at 60 psi. It does show 0.1 psi when engine off and ignition on , i don’t know wether this is an issue or not. I will be fitting a race tech 8 bar oil gauge this evening to see what readings it produces.

[DerekAE86]

Idling at 12.4 is a little rich. You can lower the fuel table some more to get it into range. Maybe 45%. But an engine will typically want to be richer on a cold start so you can probably leave it as is until you can get it fully up to temp and adjust from there.

If you can do a PC log of the RPM revving over 2k when you give it some throttle we might be able to figure out why that's happening. Might not be the TPS.

Oil pressure will change depending on oil weight and ambient temp. But 90psi does seem incredibly high. If you have access to a known good guage that would be good to double check against.

[Adamw]

The 101-0080 sensor definitely uses the "1000 kPa (150 PSI) TI Sensor" calibration, so it does sound like you have an oil pressure issue.  

[Fintank11]

 

@DerekAE86 @Adamw

Update:

Changed the running in oil for some semi synthetic 10w40 and allowed car to idle up to 72 degrees where the oil pressure dropped to 39 psi @960 rpm. (Car cuts out due to ignition timing and fuel the hotter it gets, it likes the coke start enrichment).I think when receives run in map it will continue to drop pressure and be ok. I’m wiring in a race tech oil pressure gauge this week also. 
 

New tps fitted and my sticky throttle has been fixed also.
 

thanks guys