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Toyota Chaser 1JZ VVTI Kurofune RPM spike issues


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Hi, 

I recently fitted a Link ECU and after our first start we noticed that the RPM counter in the car and engine speed values on the ECU would spike to very high numbers even just idling. (9k, 15k etc)

I did some troubleshooting using some of the other topics around the forum and checked the following things:

Troubleshooting:

  • Checked crank sensor polarity via trigger scope (Correct)
  • Checked cam sensor polarity via trigger scope (Correct)
  • Checked engine earth resistance (Cylinder head, block, alternator, inlet and chassis to negative battery terminal/Chassis) (.002 ohms so that seems correct)
  • Checked Cam sensor resistance (1200 ohms approx which is within spec)
  • Checked Crank sensor resistance (1780 ohms approx which is within spec)
  • Cleaned the crank sensor 
  • Adjusted trigger offset values with no improvements

Car information:

  •  Bosch EV14 850CC injectors (Fully sequential)
  • Toyota 1.8 Coils (Full sequential)
  • Stock cam sensor
  • Stock crank sensor
  • Trigger offset 205

I'm very much running out of ideas and now the car wont start as I'm pretty sure we have fouled the plugs where as it did start before but was very erratic.

We know we are getting Trigger errors however when we changed trigger 2 type to Optical/hall these went away but the car still didn't start. I'm putting that down to bad spark plugs which I'll replace with coppers today.

If the trigger errors go away when using optical/hall, I'm guessing that means there is to much overlap between cam/crank signals, but I'm not sure how I solve that? Should I check mechanical timing incase thats the cause?

I've attached a couple Trigger scopes, log files and map file, any help would be very appreciated!

 

Thanks

Sam

trigger scope day 2 no fuel pump just cranking.llg day 2 log export 1 (fouled plugs).llg 1jz base map.pclr day 2 trigger scope 1 (fouleed plugs).llg log export day 2.csv trigger scope day 2 no fuel pump just cranking attempt 2.llg

triggerscope pattern.jpg

CD50247D-6855-4F63-B673-FF3214605CD3.jpeg

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3 minutes ago, Brad Burnett said:

First i would put some fresh plugs in it and cut the values in the idle/low load area of the fuel pump by half(all the 77s).

Whats your base fuel pressure set to?

Base pressure is around 43-44psi 

I've had some feed back TechDave through my eletrician and according to him I have a potential bent/broken trigger tooth... 

It's worth noting the car did start before.

 

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2 hours ago, remski2 said:

Your AFR's are 16-19.

 

 

2020-03-12 16_34_54-PCLink Engine Management - C__Users_Remski_Desktop_Downloads_177698495_1jzbasema.png

Not concerned about fuel as the car did start originally but even when it did start we had engine RPM spikes which then kept activating the RPM limit etc when the car was only idling.

 

I checked the crank trigger sensor teeth tonight as per @TechDave feed back and all the teeth look fine especially before and after the gap.

Is it purely down to the cam and crank signal over lapping? If so how can I fix that? 

Worth noting the car ran fine on the stock ECU prior to the link and new loom too. Not sure how fusssy the stock ecu was with signal

 

110A5334-25A4-4F6B-9812-F4691AC7195E.jpeg

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None of the trigger scopes you have attached have any data but based on those screenshots above I would say the arming thresholds need to be much lower.  Set the whole table to about half it’s current values on both trig 1& 2

28 minutes ago, BuckinghamIO said:

This post seems to follow a similar issue...

The VVT trigger modes don’t have the same restrictions in regards to cam tooth position.  Yours looks normal for 1J/2J.

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8 hours ago, Adamw said:

None of the trigger scopes you have attached have any data but based on those screenshots above I would say the arming thresholds need to be much lower.  Set the whole table to about half it’s current values on both trig 1& 2

The VVT trigger modes don’t have the same restrictions in regards to cam tooth position.  Yours looks normal for 1J/2J.

No data as in nothing in them at all? I just downloaded them and they showed the trigger scopes fine?  If you mean nothing of concern then okay.

We have tried to lower the arming voltages with no effect but tonight I'll fit a new battery, new plugs, clean the crank sensor ground and try again.

 

Is there any way to log both trigger scope and normal logs so I can overlay them?

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23 minutes ago, BuckinghamIO said:

No data as in nothing in them at all? I just downloaded them and they showed the trigger scopes fine?  If you mean nothing of concern then okay.

Nothing at all.  Just found "Day 2 triggerscope 1" is a valid capture but neither of the other two show anything - just 0.1V of noise.

Both cam and crank are only just making 0.3V in that capture though so that is very low.  Its almost like there is no ground connected to the sensors or something.  Is it a piggy back install?

Try your arming thresholds something like this:

oCmdkHb.png

 

27 minutes ago, BuckinghamIO said:

Is there any way to log both trigger scope and normal logs so I can overlay them?

No, the triggerscope can only capture about 720deg.

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22 minutes ago, Adamw said:

Nothing at all.  Just found "Day 2 triggerscope 1" is a valid capture but neither of the other two show anything - just 0.1V of noise.

Both cam and crank are only just making 0.3V in that capture though so that is very low.  Its almost like there is no ground connected to the sensors or something.  Is it a piggy back install?

Try your arming thresholds something like this:

oCmdkHb.png

 

No, the triggerscope can only capture about 720deg.

Okay I'll try those values. Can you confirm you can see the RPM spike in the log though?

It's a standalone install, the cam sensor does make -3v to 3v when running but the crank sensor I think stays a little low.

I've also attached some other trigger scopes from the first day I was logging.

adjusting trigger 2.llg trigger scope.llg

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6 minutes ago, BuckinghamIO said:

. Can you confirm you can see the RPM spike in the log though?

Yes, the rpm spike is due to a trigger error.  This means the trigger pattern received by the processor didn’t match what it expected to see.  Most likely a tooth didn’t meet the arming threshold so it was ignored.

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On 3/13/2020 at 10:02 AM, Adamw said:

Yes, the rpm spike is due to a trigger error.  This means the trigger pattern received by the processor didn’t match what it expected to see.  Most likely a tooth didn’t meet the arming threshold so it was ignored.

Well on Saturday I finished putting car back together and I did the following:

  • Cleaned the crank sensor earth (Where the bolts also secures the sensor)
  • Replaced the battery (Much bigger and beefer version also)
  • Replaced the spark plugs

The car fired up straight away and seemed to idle without doing the whole up and down RPM rev counter thing and I even gave it a few blips of the throttle to check which all seemed great!

I did take some logs and I can see two instances of a high RPM, could I see a RPM spike on the logs from hitting the 3k limiter? as I know I did that once by accident? @Adamw

 

I've attached the latest map file, 2 trigger scopes and the log file.

Trigger Scope Log 2020-03-14 8;19;54 pm.llg Trigger Scope Log 2020-03-14 8;21;23 pm.llg 2 RPM spikes.llg latest map 1jz.pclr

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2 minutes ago, Adamw said:

Sorry, I had so many logs open tonight I must have looked at the wrong one.

Your arming threshold is still too high.  Why didnt you set them as per my example above?

Ahh my bad, sorry it was a long day on Sunday when putting the whole front of the car back together :P 

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  • 2 months later...

@Adamw 

@TechDave I believe you have spoke to Martyn at EngineTuner in regards to my issue with the Kurofune and the trigger issue and gave some insight that a 3k resistor may be needed.

The resistor has been added and Martyn has updated me to say there has been no change, which is really frustrating as I have no idea what we can try next or if I need to just completely replace the ECU as quite a significant cost when this should work... 

Any input would be greatly appreciated as I really have no clue what to do now other than to take the car back and run more checks my self.

 

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I had similar spikes on a 2JZGE VVTI with BC272 cams using Kurofune. Had to mess around with trigger two arming thresholds a lot to get the system happy and not spike. Required much more arming voltage than other 2JZ's Ive done. Unsure if its down to the ECU or the engine combo. 

Looking at your latest map you have your VVTI cam control mode set to Off, and in the logs the ECU is not able to track Inlet cam position. This could be contributing towards your sync errors. Haven't ever tried running a VVTI with cam control compeltely off, normally if I want to diagnose VVT system I just set RPM lockout very high. ECU still tracks inlet position like this which is helpful in diagnostics. If your VVT solenoid has no duty then the cam gear can bounce, especially on idle and free revving.

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3 hours ago, Mike2J said:

I had similar spikes on a 2JZGE VVTI with BC272 cams using Kurofune. Had to mess around with trigger two arming thresholds a lot to get the system happy and not spike. Required much more arming voltage than other 2JZ's Ive done. Unsure if its down to the ECU or the engine combo. 

Looking at your latest map you have your VVTI cam control mode set to Off, and in the logs the ECU is not able to track Inlet cam position. This could be contributing towards your sync errors. Haven't ever tried running a VVTI with cam control compeltely off, normally if I want to diagnose VVT system I just set RPM lockout very high. ECU still tracks inlet position like this which is helpful in diagnostics. If your VVT solenoid has no duty then the cam gear can bounce, especially on idle and free revving.

The car in with the tuners at the moment and the map posted here is out of date.

Shortly after my last post there was an update from Dave at tech support and we have another possible solution of adding much bigger resistors (25K) to emulate the trigger signal being passed through/shared via the stock ECU which isn't there in this case.

 

Interesting you say you had to really fine tune the trigger arming like that... It seems this is never a issue normal so much be down to the specific differential trigger hardware system in the kurofune.

Essentially though no matter what you do, when you hit 3,000 rpm, massive rpm spike well over 10,000 no matter what you seem to change.

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