Trigger errors and logging

[jimmylemon]

Hi guys,

I have a g4+ running a rb26/30 with one of these trigger kits:

https://rossperformanceparts.com/product/nissan-rb-36t-crank-trigger-kit-2/

Now the issue is the car will start to ramp up onto boost, then all of the sudden does this really violent bang/backfire and instantly loses power. Sometimes it does it, sometimes not and will pull clean to redline. It seems to get worse as the car gets hot. It's literally driving me insane.

Last time at the track we had to pull out of the session and go home.

Its using the Cherry sensor, with the 36-2 crank trigger disc. Had it tuned the other day, and it was getting a "few" trigger errors up top but I was told would be OK. I was told to install the 12-1 trigger disc on crank instead to attempt to resolve.

So, what I would like to do is take it for a run tonight, and log everything it does back to a laptop. Can someone give me a quick run down of how to get it recording back to laptop?

I just want something I can save, that someone on here can look at and just confirm what the cause is.

Cheers.

[Adamw]

A 36-2 trigger disc should be fine, I dont think you are going to achieve anything by changing to a 12-1.

I would start by doing a couple of triggerscope captures.  Do one at idle initially and one while holding it at say 5000RPM.  That might give us some clues whats wrong.  Here is a quick video showing how to do a triggerscope:  https://1drv.ms/v/s!AiYbYlZQuRHPmieMTkwQDCXEb2LY

 

Here is a video how to do a PC Log if you want to record a drive:  https://www.youtube.com/watch?v=_P1LRANeO4A

 

[jimmylemon]

Thanks Adam, ill move onto doing a triggerscope then. That link doesn't appear to be working for the triggerscope, do you have that somewhere else I can download?

Cheers.

[Adamw]

20 minutes ago, jimmylemon said:

That link doesn't appear to be working for the triggerscope

Hmm, thats odd, seems to work for me.  I will email you a copy.

[jimmylemon]

Thanks Adam I got that. Was just having a read of this:

http://www.cpgnation.com/forum/threads/inductive-vs-hall-effect-sensors-something-to-consider.21418/

This comment:

Always twist the three wires together and shielding them is always a good idea.

Should I be using shielded cabling and twisting?  Just trying to do anything I can to fix it.

[Adamw]

Most of that post you linked is complete rubbish, but for sure, trigger wires should always be shielded though.  Are yours not?

[jimmylemon]

OK cool, yeh I was taking some of it with a grain of salt, the main one I was concerned with was the shielding part.

What I have done is met up with the existing nissan CAS shielded wiring/loom.

Because the rb26 has no factory crank pickup but, I think I may have run 3 short un-shielded wires from the crank cherry, to meet up with the factory nissan shielded wiring. All i did was chuck some conduit around it.

The cam pickup goes straight into the nissan shielded wiring.

Cheers.

[jimmylemon]

Hey Adam,

Just an update on this, I have re-wired all the triggers with shielded all the way back to the ECU connector for both sensors. I took it for a run after this, still the same.

I finally got around to taking it for a run tonight and logging the drive, it happened twice whilst driving on this occasion, one should be towards the back of the log.

My tuner couldn't find the issue, so I'm at a cross road.

Here is the log:

https://1drv.ms/f/s!AgHRVnwxDzLUiWcpUzL-Kv8n6k7_

Cheers.

I should add as well, it seems to be most apparent going into 3rd gear, then putting the power down.

Also it doesn't seem to be that apparent on the dyno, as in the tuner reported he was getting trigger errors higher in the rev range,  but we could do full power runs without much issue. Soon as it hits the street, its pretty much not drive able, soon as it hits 3rd and the power comes on it does it.

 

20219.pclr

[Adamw]

Did you do the trigger scope?

[jimmylemon]

I can do it again, but pretty sure I did it once before and didn't find any issues.

[Adamw]

Do 1 at idle and another at say 5000rpm

[jimmylemon]

OK ill try that tonight. Did the log reveal that it is having trigger issues Adam?

[jimmylemon]

OK did multiple trigger scope's few at idle, few at 4K, few at 5k ish.

Can you take a look when you get a chance Adam and tell me what you think?

Cheers mate.

Trigger Scope Log 2019-02-27 9;33;41 am.llg Trigger Scope Log 2019-02-27 9;33;56 am.llg Trigger Scope Log 2019-02-27 9;34;08 am.llg Trigger Scope Log 2019-02-27 9;34;24 am.llg Trigger Scope Log 2019-02-27 9;34;38 am.llg Trigger Scope Log 2019-02-27 9;34;53 am.llg Trigger Scope Log 2019-02-27 9;35;07 am.llg Trigger Scope Log 2019-02-27 9;36;05 am.llg

Also I *think* that the top cam cherry sensor is disable in the tune, is that correct?

It has priority set to trigger 1 which is crank, but I don't think the top trigger 2 on the cam is setup at all?

[Adamw]

I dont think you have a trigger problem.  It looks like you are hitting the MAP limit (boost cut).  It happened twice in that log, once about 8 minutes in and again about 20mins in near the end.

Your MAP limit is set to 380Kpa, and you are getting to about 373Kpa in the logs.  The MAP limit if using our default settings will start to limit 10Kpa early.  

 

 

Also, just so you are aware, your tune has some fairly weird setup on the idle ignition control, it is activating pretty much any time you are below 2500RPM retarding timing to zero degrees, so I suspect that makes it drive a bit odd at small throttle openings.

[jimmylemon]

OK thanks heaps for that Adam. Would simply removing the MAP limit work for me as a test?

Your are correct, it drives terrible with light throttle load, its hard to explain, but its very on/off/jerky with light throttle.

[Adamw]

You need to be sure that it is ok to run more boost than expected but if so you can just add another 20KPa to the numbers in your MAP limit table should prevent it from interfering.

Set up your idle ignition and speed sources like below should help with the low speed drivability.

 

[jimmylemon]

Awesome thanks Adam, will give that a try tonight then.