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Popeye775

Rough Start

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That was the best drive it’s had in a long time. The only spot I really felt a miss (other than a tiny bit on takeoff) was in third gear if I went full throttle around 2.5k rpm


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Plugs after most recent run. One plug looks a little whiter than the others that’s for sure but they are looking better. 148fc978803b86fee8d23163b3b01aaf.jpg


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On 8/16/2020 at 11:21 AM, Popeye775 said:


When it comes to adjusting the CO pot, do you do it while the car is on or off? Also I’m assuming in 1/4 turn increments clockwise?


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1/2 turn increments should be easier to tell if it’s getting better.

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On 8/16/2020 at 11:51 AM, Popeye775 said:

So I did some research and from what it seems the CO pot should be set to 500ohm. That way it isn’t pulling or adding fuel. So what I did was set mine to 500ohm and I will see how it feels from that adjustment


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I think 500 ohm was the factory’s starting setting, but still needed adjustment before capping the pot off.  Each G60 got its differences and the CO pot was a way to tune for the right air fuel mixture.

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On 8/16/2020 at 1:48 PM, Popeye775 said:

Plugs after most recent run. One plug looks a little whiter than the others that’s for sure but they are looking better. 148fc978803b86fee8d23163b3b01aaf.jpg


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That’s better lighting to read the plugs.  That’s too lean of a mixture for boost.  It might be okay for short runs, but will be inconsistent due to knock and timing pull. For economy you’d want all your plugs looking like #2.  Though that still looks too lean for my taste of tuning. For all out full throttle top speed fast and the furious runs, you want the plugs looking dark grey and sooty.

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1 hour ago, Bennitoapplebum said:

That’s better lighting to read the plugs.  That’s too lean of a mixture for boost.  It might be okay for short runs, but will be inconsistent due to knock and timing pull. For economy you’d want all your plugs looking like #2.  Though that still looks too lean for my taste of tuning. For all out full throttle top speed fast and the furious runs, you want the plugs looking dark grey and sooty.

Awesome, I will turn the CO pot down more then. I know that the timing and spark plug gap are good, so I will work with the CO pot to richen it up! Thank you sir

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Update: 

Took the car out for a little drive again - i have not pulled the plugs yet - and it still feels misfire-like under 2k rpm but it is off and on. It does it on take off and what seems to be under that RPM of 2k. Something new, when I turned the car back on after driving it for a while then letting it sit a couple minutes, it idled perfect and revved perfect for about 30 seconds then went back to it's misfire-like ways under 2k.

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Advice real quick here:

So I am considering trying this. I was adjusting the CO Pot today along with the idle air screw, but I am thinking that what I should do is set the CO Pot back to 500, then set the idle air screw from there and then set the CO Pot accordingly for that. Would this be a good way to go about trying to tune this thing or not? I am going to order a wideband as well because I think that will help a lot when it comes to trying to get this thing dialed in 100%

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10 hours ago, Popeye775 said:

Advice real quick here:

So I am considering trying this. I was adjusting the CO Pot today along with the idle air screw, but I am thinking that what I should do is set the CO Pot back to 500, then set the idle air screw from there and then set the CO Pot accordingly for that. Would this be a good way to go about trying to tune this thing or not? I am going to order a wideband as well because I think that will help a lot when it comes to trying to get this thing dialed in 100%

Yes you can tune the idle that way, the mixture and idle speed go hand in hand so constant back and forth adjustment might be required. Yes getting a wideband will definitely help with tuning and diagnostics.  

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15 hours ago, Popeye775 said:

Update: 

Took the car out for a little drive again - i have not pulled the plugs yet - and it still feels misfire-like under 2k rpm but it is off and on. It does it on take off and what seems to be under that RPM of 2k. Something new, when I turned the car back on after driving it for a while then letting it sit a couple minutes, it idled perfect and revved perfect for about 30 seconds then went back to it's misfire-like ways under 2k.

Would you say that your engine has reached a higher temperature while sitting?  If so, then heat related intermittent problems are, guess what... ground related.  When metal expands under heat it sometimes increases the current capacity in poor grounds.

This may not be your case.  Just something to think about.

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Would you say that your engine has reached a higher temperature while sitting?  If so, then heat related intermittent problems are, guess what... ground related.  When metal expands under heat it sometimes increases the current capacity in poor grounds.
This may not be your case.  Just something to think about.

No sir. The problem also doesn’t get worse as the car warms up. It is pretty consistent usually


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So i set it to 500 ohm and adjusted the idle air screw accordingly. Due to the advancement in timing that I did the other day, I still needed to up the ohms to take some fuel out to drop the idle a bit. Gonna rest drive in a bit and give an update


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Minor update: got the car smoke tested. It has zero vacuum leaks and zero boost leaks. So I’m assuming either just needs to be tuned more, or possible ground issue?


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On 8/21/2020 at 2:26 PM, Popeye775 said:

Update: 

Took the car out for a little drive again - i have not pulled the plugs yet - and it still feels misfire-like under 2k rpm but it is off and on. It does it on take off and what seems to be under that RPM of 2k. Something new, when I turned the car back on after driving it for a while then letting it sit a couple minutes, it idled perfect and revved perfect for about 30 seconds then went back to it's misfire-like ways under 2k.

Shutting down the engine after a drive causes an engine to go into “heat soak” mode.  The entire engine heats up due to the cylinder’s heat not being transferred to the radiator, fuel cooling, etc.  When you restart the car during this stage the ECU delivers an increased ASE(after start enrichment) for a period of time~30 sec.

Judging from the symptoms you explain and from the color of your plugs, your issue seems to be fuel related.  Any ignition system will have a hard time lighting a mixture as lean as yours, especially during increased load.

A quick test would be to crank that CO pot up by a large amount and see if she drives better or worse.  I’m betting it will run way smoother and consistent.

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Shutting down the engine after a drive causes an engine to go into “heat soak” mode.  The entire engine heats up due to the cylinder’s heat not being transferred to the radiator, fuel cooling, etc.  When you restart the car during this stage the ECU delivers an increased ASE(after start enrichment) for a period of time~30 sec.
Judging from the symptoms you explain and from the color of your plugs, your issue seems to be fuel related.  Any ignition system will have a hard time lighting a mixture as lean as yours, especially during increased load.
A quick test would be to crank that CO pot up by a large amount and see if she drives better or worse.  I’m betting it will run way smoother and consistent.

We will also find out this weekend how it’s running. I just got my wideband gauge in and will be installing tomorrow


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Huge breakthrough when it comes to the car and how it runs. So here's what I did. I decided to try and increase the gap .001 to see what would happen. From .025 -> .026. The car loved it. It idled a lot better and even revved a lot better. I did mess with the CO Pot a little bit more, but ended up putting it right back to 517 ohm like it was before. It definitely is still missing a little bit, but not like it was just a couple days ago. I am going to try to increase the gap again to .027 and see if that completely solves the issue as well. Tomorrow I will also be installing - or working on installing - that wideband gauge in order to properly dial in the air/fuel mixture. Although it feels pretty good mixture wise currently and the plugs are reflecting that a bit. 

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Update for you sir,

I wanted to test something out. I put stock gapped plugs in the car (.024) and turned down the CO Pot until it idled smooth ( as in the video) with the CTS unplugged. BUT as soon as the CTS was plugged back in, you will hear the idle dip and hear a change in idle. Bad CTS maybe? The other thing that I am a little concerned about is the fact that the CO Pot is at 80 ohms of resistance in the video. From what I have read, 500 ohm is where fuel is neither added or taken out. 80 just seemed a little low, even if it is idling smoother. Ideas?

https://www.youtube.com/watch?v=3RCDoGGEUzU

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2 hours ago, Popeye775 said:

Update for you sir,

I wanted to test something out. I put stock gapped plugs in the car (.024) and turned down the CO Pot until it idled smooth ( as in the video) with the CTS unplugged. BUT as soon as the CTS was plugged back in, you will hear the idle dip and hear a change in idle. Bad CTS maybe? The other thing that I am a little concerned about is the fact that the CO Pot is at 80 ohms of resistance in the video. From what I have read, 500 ohm is where fuel is neither added or taken out. 80 just seemed a little low, even if it is idling smoother. Ideas?

https://www.youtube.com/watch?v=3RCDoGGEUzU

Was the car fully warmed up while the CTS was unplugged?  You could’ve bee adjusting the CO while the engine was warming up, or cooling down.  I don’t know what function unplugging the CTS serves while adjusting CO.  I do know that both CO pot and coolant sensors are important for fueling equations within the ECU.  
 

I kind of remember unplugging the CTS at one point, for adjusting CO.  But eventually ended up leaving everything plugged in while making any adjustments.  

Does anyone here know why the procedure calls to unplug the coolant sensor?

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3 hours ago, Popeye775 said:

Update for you sir,

I wanted to test something out. I put stock gapped plugs in the car (.024) and turned down the CO Pot until it idled smooth ( as in the video) with the CTS unplugged. BUT as soon as the CTS was plugged back in, you will hear the idle dip and hear a change in idle. Bad CTS maybe? The other thing that I am a little concerned about is the fact that the CO Pot is at 80 ohms of resistance in the video. From what I have read, 500 ohm is where fuel is neither added or taken out. 80 just seemed a little low, even if it is idling smoother. Ideas?

https://www.youtube.com/watch?v=3RCDoGGEUzU

Also another thing to point out:  The injector flow.  I recall you had purchased a new set of injectors.  If the flow rate deviates from factory, you may be having to compensate with the CO pot.  I’d say wait for the wideband installation to help simplify some things.

 

 

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Was the car fully warmed up while the CTS was unplugged?  You could’ve bee adjusting the CO while the engine was warming up, or cooling down.  I don’t know what function unplugging the CTS serves while adjusting CO.  I do know that both CO pot and coolant sensors are important for fueling equations within the ECU.  
 
I kind of remember unplugging the CTS at one point, for adjusting CO.  But eventually ended up leaving everything plugged in while making any adjustments.  
Does anyone here know why the procedure calls to unplug the coolant sensor?

Car was fully warmed up. As far as I know, the CTS must be unplugged in order to adjust the CO accurately. But I could be wrong


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11 hours ago, Popeye775 said:


Car was fully warmed up. As far as I know, the CTS must be unplugged in order to adjust the CO accurately. But I could be wrong


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I remember why the CTS needs to be unplugged while adjusting the CO. The ISV idle stabilizer is inactive while the CTS is unplugged.  You get the idle speed close to ~800 using the bypass screw. And  adjust the CO using a wideband.  After the adjustments, you plug the CTS back in and the ISV will hold the idle speed closest to 800rpm with the varying load, power steering, fans, acc, etc.

So in your video, your idle was too high.  When you plugged your CTS back in, the ISV pulled the engine back to its target idle speed.  

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On 8/31/2020 at 8:54 PM, Bennitoapplebum said:

I remember why the CTS needs to be unplugged while adjusting the CO. The ISV idle stabilizer is inactive while the CTS is unplugged.  You get the idle speed close to ~800 using the bypass screw. And  adjust the CO using a wideband.  After the adjustments, you plug the CTS back in and the ISV will hold the idle speed closest to 800rpm with the varying load, power steering, fans, acc, etc.

So in your video, your idle was too high.  When you plugged your CTS back in, the ISV pulled the engine back to its target idle speed.  

SO here is where we are. The wideband is installed and started reading. When it is idling, the AFR is bouncing between 14-18.5. When on throttle/starting to drive, the AFR is around 14.5. With the CTS unplugged, the AFR will sit around 13.5-14.5 and the idle will sound smooth. So basically what it seems is that it is becoming very rich upon idle? 

Does anybody know what the PROPER AFR is suppose to be? From research it seemed to need to be around 14.75, but I could be wrong.

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25 minutes ago, Popeye775 said:

SO here is where we are. The wideband is installed and started reading. When it is idling, the AFR is bouncing between 14-18.5. When on throttle/starting to drive, the AFR is around 14.5. With the CTS unplugged, the AFR will sit around 13.5-14.5 and the idle will sound smooth. So basically what it seems is that it is becoming very rich upon idle? 

Does anybody know what the PROPER AFR is suppose to be? From research it seemed to need to be around 14.75, but I could be wrong.

This type of fuel injection system fires all injectors at once per engine cycle.  It requires a slightly richer idle. 13.5-14.5 is probably the leanest it will idle smoothly.  Anything leaner will surge and hunt for stability.  14.7 is ideal, but not realistic with this injection system.

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8 minutes ago, Bennitoapplebum said:

This type of fuel injection system fires all injectors at once per engine cycle.  It requires a slightly richer idle. 13.5-14.5 is probably the leanest it will idle smoothly.  Anything leaner will surge and hunt for stability.  14.7 is ideal, but not realistic with this injection system.

So how would I be able to adjust it down at idle with the CTS plugged in? because that is where my issue is. With it unplugged it seems good

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35 minutes ago, Popeye775 said:

So how would I be able to adjust it down at idle with the CTS plugged in? because that is where my issue is. With it unplugged it 

1 hour ago, Popeye775 said:

SO here is where we are. The wideband is installed and started reading. When it is idling, the AFR is bouncing between 14-18.5. When on throttle/starting to drive, the AFR is around 14.5. With the CTS unplugged, the AFR will sit around 13.5-14.5 and the idle will sound smooth. So basically what it seems is that it is becoming very rich upon idle? 

Does anybody know what the PROPER AFR is suppose to be? From research it seemed to need to be around 14.75, but I could be wrong.

Was all this with the CO pot at ~500ohms?  Your CTS sensor might be out of range, or your engine may have been still warming up, while unplugging the CTS. By any chance you have the factory thermostat in there? 

 

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