2jzge itb intermittent rough idle and starting

[tdgarage]

Hey guys, been chasing this issue with my cressida for a while. i'll try to make it short.

2jzge, ITB, DBW, R35 injectors set at 50psi, factory distributor, NGK 1.1mm spark plugs

before the DBW set up i was never able to get a clean start and run. Always had to shut off, and restart. Sounded and felt like it would start rough as if running on 5 cyliders.

now after the DBW set up i still get this issue, and sometimes if the engine is not shut off the roughness randomly clears up and a restart is not necessary. 

Another issue that i just experienced today on a start up today is that the rpm goes to 2000 rpm, and when driving the it drives rough. however when i shut the engine off and start the car again something seems to reset, and it goes back to running smooth and at 1100 rpm.  Odd thing is when it's running at 2000rpm the tps still shows 2.1 as it does when it's running at 1100rpm.  while it was running at 2k rpm i managed to log it and drove it a bit to see if anything shows up. 

 

anyone still running factory distributor on their 2jzge with no issues?  let me know if you see any issues in the tune or log. maybe i should take a video and upload it. 

Thank you

 

 

5222023.pclx PC Datalog - 2023-05-22 7;59;16 pm.llgx

[Vaughan]

Do you have a log of it idling properly to compare against? Also it being richer than target might be helping hold the idle up, maybe try leaning it off back towards target while it is idling high to see if that fixes it.

I would also recommend setting the 0 APS row of the E-Throttle target table to 0% TPS target and using the regular idle control stuff to control the E-Throttle Target when under idle conditions.

Other than that is there any way you could have an air leak or a sticky throttle blade and have the throttles been balanced properly?

[Adamw]

There are quite a few pretty odd settings in your map so I have made some adjustments to get it back to a more typical starting point.  Can you try loading this map and doing another log. It may not be immediately better since a lot of my settings are just guesses, but provided it is close enough to idle we will likely get it better after the next log. 

Is your IAT sensor reading correct?  70degC at idle seems a bit extreme for a NA ITB engine.

You can use use the file compare function to see what I changed.

5222023 idle tweaks.pclx

[tdgarage]

I don't have any type of IAC on the engine. Now with the DBW i figured i could use that as an IAC like newer cars, that's why i had the first two cells at 20%. I'll try leaning out a bit also. i've noticed that it has been a bit too rich. Thank you

I've checked all throttle plates to make sure they are synced and all the arms are fastened tight on the throttles and dbw. Nothing is loose.

However the way it acts right now seems like one set of itb's open up a lot more than the other ones every once in a while, enough to raise the RPM, but keep the TPS numbers as they are. Kind of hard to figure out which since it's not a constant problem. 

I did a couple of logs. one log is a rough low rpm that smooths out, next one is a normal idle, and the car drives great. next one is high rpm and not drivable. 

I uploaded Adam's map (thank you) and logged it. it started at a bit lower rpm and sounded smooth, but when in gear and driving it was rough similar to before. 

It seems mechanical since i can't think of anything on the ecu that can come up randomly. which i may have to investigate further.

If on the smooth/normal idling if you guys see anything off please let me know such as if you see any issues with trigger set ups, or fueling. there's still some more tuning left, it was just stopped because this high rpm rough driving came up during the session. 

 

 

roughtosmooth.llgx normal.llgx highrough.llgx tweek.llgx

[Vaughan]

17 minutes ago, tdgarage said:

I don't have any type of IAC on the engine. Now with the DBW i figured i could use that as an IAC like newer cars, that's why i had the first two cells at 20%. I'll try leaning out a bit also.

If you setup the idle control it sorts it all without needing weird stuff in the E-Throttle target table.

18 minutes ago, tdgarage said:

I've checked all throttle plates to make sure they are synced and all the arms are fastened tight on the throttles and dbw. Nothing is loose.

Have you checked plate angles or have you checked how much vacuum each is drawing?

[Adamw]

ITB's need to be balanced with a synchrometer or manometers/vacuum gauges if there are individual vac nipples, you cant do it by feel/look/measurement.

[tdgarage]

On 5/24/2023 at 3:56 PM, Vaughan said:

If you setup the idle control it sorts it all without needing weird stuff in the E-Throttle target table.

Have you checked plate angles or have you checked how much vacuum each is drawing?

 

4 hours ago, Adamw said:

ITB's need to be balanced with a synchrometer or manometers/vacuum gauges if there are individual vac nipples, you cant do it by feel/look/measurement.

thank you for the info.

Do you mean to leave the ethrotle at 0, but add an IAC valve? or set up IAC in the program? sorry trying to make sure if i'm understanding it right.         

I double checked the balance between the throttles using a synchrometer on each velocity stack. they were all reading 7kg on all 6. 

Note: I feel like this random high idle and rough driving came after i installed and set up the DBW, This issue wasn't there before when it was cable driven. 

I thought maybe there is an issue with tps calibration, so i set ethrottle on set up again, and hit calibrate, and it went through the sweep and finalizing calibration. I also did it again through the ECU Control drop down to TPS calibration and it did the same thing. but i was still having the issue after setting the ethrottle targets 0 cells to 0% but ended up with the same issue.

I tried doing a TPS calibration again, but right as it started it came up with "Error 5: No TPS (Main) Movement" even though pressing the pedal down and dbw opening i can see the main tps reading. 

I'm wondering if this is causing the issue? I'm sorry, been chasing this for a bit i'm trying to give as much detail as i can to help, and this popped up in my head thinking it may be an issue that can randomly pop up.  Thinking the TPS on the end of the first set of throttle was causing this issue, i unplugged it to see if the problem goes away, and it didn't change.

Thanks again.                                     

[Adamw]

It looks like I missed the base position table in the last map I supplied above.  We should check TPS calibration again as in those last logs you are idling at 1700RPM with only 1.5% TPS which may indicate the throttles are actually open more than the TPS shows.  

So, load in this new map, go to > Electronic Throttle>E-throttle 1, set it to setup mode.  Start a PC Log (F8), Then go to > Electronic Throttle>E-throttle 1>Throttle position sensor, double click on the TPS calibration spanner, follow the instructions onscreen.  Stop the log and save it as "TP cal".  If the TP calibration failed then post the log here.  If successful, set the e-throttle mode back to "ON", do a store.   

Do a new log of a start-up and some idling.

 

5222023 idle tweaks v2.pclx

[tdgarage]

On 5/25/2023 at 9:47 PM, Adamw said:

It looks like I missed the base position table in the last map I supplied above.  We should check TPS calibration again as in those last logs you are idling at 1700RPM with only 1.5% TPS which may indicate the throttles are actually open more than the TPS shows.  

So, load in this new map, go to > Electronic Throttle>E-throttle 1, set it to setup mode.  Start a PC Log (F8), Then go to > Electronic Throttle>E-throttle 1>Throttle position sensor, double click on the TPS calibration spanner, follow the instructions onscreen.  Stop the log and save it as "TP cal".  If the TP calibration failed then post the log here.  If successful, set the e-throttle mode back to "ON", do a store.   

Do a new log of a start-up and some idling.

For some reason my log files are too large to upload on here. what's the best way to compress them? even though they are smaller than the first set of logs I posted on here. 

However the calibration did work this time, and i made 5 logs of different start ups and idling. and a short distant drive. 

[castillaricardo]

Upload the logs to a filesharing site like Google Drive or Dropbox and post a sharing link here. You might have hit your quota limit on the forum.

[tdgarage]

14 minutes ago, castillaricardo said:

Upload the logs to a filesharing site like Google Drive or Dropbox and post a sharing link here. You might have hit your quota limit on the forum.

ahhh yes that makes sense, thank you. 

 

https://drive.google.com/drive/folders/1t0yfUvadzy-M4ZhJhVBEIWoA5U25ihv1?usp=sharing

 

Let me know if this works please?

 

[tdgarage]

in case the logs do show up. I'm just going to enter some data from what the car did and what i felt.

after the V2 upload, tps calibration. the car started fine, didn't get the high idle anymore, it would start high but then level out. 

most of the times when it shut off and had to be restarted was by the car itself. I did not physically shut off the engine. 

at very low rpm idle, when i tried to push the pedal the rpm and engine would be rough, but then it would catch itself and idle correct and i could raise the rpm.

I think it's idle 4 log, the car was idling low rpm and i could feel like a kick something from the engine bay like something was switching on and off.

the rpm would be low, and i would feel and hear this change and the rpm would smooth out, then it would drop, and again after the kick it would smooth out. almost like one injector shuts off, and kicks back in, or spark plug. I think as it was happening i started the log4. 

I tried driving it a little (even in first gear going 10 feet) i can tell if it's going to be smooth or bad. It idles fine, but as soon as there's load on the engine trying to move it will be choppy which shows in the previous logs. 

again it's weird, like mentioned before it seemed like a switch, something on the engine changes and it effects how it runs, and it's a noticeable change.

[castillaricardo]

4 hours ago, tdgarage said:

ahhh yes that makes sense, thank you. 

 

https://drive.google.com/drive/folders/1t0yfUvadzy-M4ZhJhVBEIWoA5U25ihv1?usp=sharing

 

Let me know if this works please?

 

Yep, I can see them.

[Adamw]

Most of the stalling and odd behaviour around idle is a trigger issue, your RPM randomly drops to zero, this of course will trigger many startup strategies such as crank enrichment, post-start enrichment, start-up offset etc which will mess up the tune.  Post a triggerscope at idle, it may just be arming threshold or similar.  

 

In the "V2idle3" log where it is idling too low, this is due to the MAP lockout, so increase that to say 85Kpa.  There are still a few other bits of the idle control that look like they need work but get the trigger and MAP lockout fixed first and do some new logs. 

Can you also give us a photo or description of the mechanical setup - where the throttle position sensor is fitted and how the motor is linked to the throttles etc, there are a few odd spots in your logs where the TPS jumps like 0.5% but the RPM doesnt change - like there is some freeplay or backlash or something? 

[tdgarage]

On 6/5/2023 at 4:57 PM, Adamw said:

Most of the stalling and odd behaviour around idle is a trigger issue, your RPM randomly drops to zero, this of course will trigger many startup strategies such as crank enrichment, post-start enrichment, start-up offset etc which will mess up the tune.  Post a triggerscope at idle, it may just be arming threshold or similar.  

 

In the "V2idle3" log where it is idling too low, this is due to the MAP lockout, so increase that to say 85Kpa.  There are still a few other bits of the idle control that look like they need work but get the trigger and MAP lockout fixed first and do some new logs. 

Can you also give us a photo or description of the mechanical setup - where the throttle position sensor is fitted and how the motor is linked to the throttles etc, there are a few odd spots in your logs where the TPS jumps like 0.5% but the RPM doesnt change - like there is some freeplay or backlash or something? 

I put another idle log on the Drive, along with 2 trigger scopes, and 2 pics, of the linkage and tps. 

The tps had some play before, so i shimmed it, and sealed it which made it better. But the tps itself maybe shit. 

the DBW linkage connects to a rod which controls the 3 itbs. there isn't much room otherwise i would have loved a more direct set up with less links.

Also on the v2idle5 it seemed to be smooth and good, after i stopped the log and the ECT started going up, the rpm dropped and then it started acting up where it drops really low and runs rough then goes back to normal then drops and runs rough again. I didn't make any changes to anything on this log.  but i did notice more changes with higher ECT numbers. 

https://drive.google.com/drive/folders/1t0yfUvadzy-M4ZhJhVBEIWoA5U25ihv1?usp=sharing

[tdgarage]

Good day,

So i changed the Map lockout as per your advice.

I did a longer log from 17c ECT to 82c. as it got warmer the rpm dropped and towards the end around 80c or so it did the rpm drop and raise.

I did not drive it, and will have to do some touch up on the starting since it took a couple of restarts to get a clear start. 

[Adamw]

You've still got a trigger issue but it wasn't captured in your original trigger scope.  Can you do a few trigger scope captures next time the idle starts to go all erratic, hopefully one will catch the issue.  

Have you checked rotor phasing in this engine before?  Turn the engine by hand to 5ATDC and check that the rotor is still just in contact with the post in the cap, similar to the pic below.

[tdgarage]

I had not done this check before. (pics and trigger scopes loaded on Gdrive) trigger scope 3-18

I added 4 pics of the process you mentioned. I marked the rotor with 3 lines, the front, center, and rear face of the rotor. I made a line on the #1 cap pin. When i put the cap on the distributor it lined up with the front section of the rotor. so at 5 degrees the rotor was just arriving at cylinder 1 position. 

I added a bunch of trigger scopes as well. i captured some when the engine would dip to low rough idle, and when it would go back to normal idle. 

holding the rpm at around 2k constantly didn't cause the engine to switch from low rpm to normal rpm. I also captured some trigger scopes from that.

[Adamw]

There's no smoking bullet, but some of these scope captures make me feel stronger that it could be a rotor phasing issue. 

In some of the scopes where the RPM is lower you get some spikes come through on the trigger waveform - there are often 2 spikes separated by 4 teeth which would be 2 adjacent cylinders firing, these 2 cylinders possibly had the most retarded ign so the rotor was too far away which causes a very high voltage spark.  

 

The idle ignition minimum clamp is currently set to -5BTDC, which would put the rotor another 10 deg further away from the post than your photos show.  Its hard to gauge from the photos but I think that is a fairly big gap to jump.  As a quick test can you try setting the idle ign minimum clamp at 5 or even 10BTDC to see if that fixes the trigger errors/dropouts.  

 

[tdgarage]

yes, i noticed those so i tried taking a bunch of captures to see if there are any higher ones. i'll try changing the numbers and post a log. 

 

[tdgarage]

 i added 2 trigger scopes "triggerscopelvl4. triggerscope loglvl4" and a log "Trigger lvl4"

I changed the Trigger 1 threshold on the 500 and 1000 rpm, and changed trigger filter from the original 1, to level 4. 

my trigger 2 is not synced, didn't want to change anything on that, and wanted to see if i could smooth things out with trigger 1.

had low rpm, but smoother. didn't have the switching between low rough idle back to normal smooth idle. A couple of times when it was low enough, engine shut off. 

It was a bit more difficult to capture a high 3v spike on the trigger scope, but there was still a couple of instances where there were some spikes at the 900 ish RPM. 

It seems like it's closer to smooth running, but trying to figure out this trigger error. factory replacement 2jz spark plugs, gapped at 1.0mm. and they were just installed. cap and rotors are fine.  

[Adamw]

20 hours ago, Adamw said:

As a quick test can you try setting the idle ign minimum clamp at 5 or even 10BTDC to see if that fixes the trigger errors/dropouts.  

Did you do this yet?

[tdgarage]

yes. i have it at 5 BTDC with the new log and captures 

[tdgarage]

I started the car today, and i tried syncing trigger 2 to cam x1 thinking maybe it would eliminate trigger errors and the ecu would have more information. 

but when i tried to rev the engine it seemed choppy and rough. I went back to only trigger one and let the engine warm up. I wanted to verify that it wasn't experiencing the "on/off" idle at higher ETC which it didn't. Only thing it did was drop the rpm to about 900 or so but didn't experience any of the rough idle or back and forth. 

may be on the right track to smoothing the rest of it out.

I added the "cressida 2023" file to the Drive with the 5 BTDC minimum clapm, trigger 1 adjustments. 

[0x33]

GE Distributors seem to be quite sensitive on G4X issues to trigger issues predominantely around idle, have seen a few so far. Try putting Trigger 1 and Trig 2 filtering to level 4. Has worked for me on a few now. 

Here are settings I've used sucessfully on a GE distributor that was giving the same trigger scope as you had above. Your trigger offset will be different depending on where you set the distributor.