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V1 RPM Fluctuations/Stalling
- Gtstorey Goblin Guru
Assuming the codes come back
What is the state of your battery? What is the voltage both running and not? That is the first thing I check with a bunch of seemingly unrelated codes.
After that I would clean all grounds.
Get the actual factory service manual and perform the diagnostic steps for the individual codes.
The first and last codes listed aren’t available codes for later models. They may still be applicable to the earlier models but there was a recent discussion on the Camaro5 forum where the aeroforce gauges where giving non applicable codes. Just something to be aware of.
I will be surprised if this is a replace parts to fix unless it’s the ECM. To many individual property for that. Unless some of these things are failed in the tune to force it to run in a certain mode (open/closed loop, speed density, etc) I don’t know enough about the non LNF tuning to know if that is a possibility.
What is the state of your battery? What is the voltage both running and not? That is the first thing I check with a bunch of seemingly unrelated codes.
After that I would clean all grounds.
Get the actual factory service manual and perform the diagnostic steps for the individual codes.
The first and last codes listed aren’t available codes for later models. They may still be applicable to the earlier models but there was a recent discussion on the Camaro5 forum where the aeroforce gauges where giving non applicable codes. Just something to be aware of.
I will be surprised if this is a replace parts to fix unless it’s the ECM. To many individual property for that. Unless some of these things are failed in the tune to force it to run in a certain mode (open/closed loop, speed density, etc) I don’t know enough about the non LNF tuning to know if that is a possibility.
Joebob
Goblin Guru
- Joebob Goblin Guru
I will throw my two cents in as well. Hopefully something sticks.
From my build log: "I have been having P2138 errors where the car would go into reduced power mode intermittently. Clearing the codes also clears my drive cycle and emission readiness monitors. I read that it is most likely a wiring issue and as we have to extend the wires, we have 12 connects that can be not perfect. Since the two sensors are so sensitive, they are more sensitive to any resistance change compared to a simple supply wire. I didn't want to mess with any of it anymore so I bought a new pedal, connector pigtail, and a length of 6 conductor shielded cable. I installed the pedal, soldered the pigtail ends and fished the shielded cable bundle down the tunnel to the ECM. Opened up the ECM plug loom and spliced the wires in about 6" from the plug to eliminate as much "bad" wire and connections. Plugged it all back together and let idle for 5 minutes to relearn. Have not driven much but noticed the just off idle does not jump from 900 to 1300 rpm but more like to 1100 rpm. maybe the sensor and wiring change but is not as big a jolt at initial tip in."
Previous to that I was getting weird gremlins and one of the propertied fixes was to ground the casing of the ECM and TCM (if you got on) to the chassis ground.
Like others have said, check and clean the grounds as well as plug in and unplug the connectors several times with the battery unplugged. Many of these connectors were designed to be safely inside the car but now are at the whim of the elements.
There are diagnostic youtube videos for sensors and wiring:
That can help determine if something is wrong.
A simple $20 Bluetooth OBDII dongle and a free app are wonders for pulling codes and data logging sensors and engine performance.
From my build log: "I have been having P2138 errors where the car would go into reduced power mode intermittently. Clearing the codes also clears my drive cycle and emission readiness monitors. I read that it is most likely a wiring issue and as we have to extend the wires, we have 12 connects that can be not perfect. Since the two sensors are so sensitive, they are more sensitive to any resistance change compared to a simple supply wire. I didn't want to mess with any of it anymore so I bought a new pedal, connector pigtail, and a length of 6 conductor shielded cable. I installed the pedal, soldered the pigtail ends and fished the shielded cable bundle down the tunnel to the ECM. Opened up the ECM plug loom and spliced the wires in about 6" from the plug to eliminate as much "bad" wire and connections. Plugged it all back together and let idle for 5 minutes to relearn. Have not driven much but noticed the just off idle does not jump from 900 to 1300 rpm but more like to 1100 rpm. maybe the sensor and wiring change but is not as big a jolt at initial tip in."
Previous to that I was getting weird gremlins and one of the propertied fixes was to ground the casing of the ECM and TCM (if you got on) to the chassis ground.
Like others have said, check and clean the grounds as well as plug in and unplug the connectors several times with the battery unplugged. Many of these connectors were designed to be safely inside the car but now are at the whim of the elements.
There are diagnostic youtube videos for sensors and wiring:
A simple $20 Bluetooth OBDII dongle and a free app are wonders for pulling codes and data logging sensors and engine performance.
YoungGun
Active Member
- YoungGun Active Member
How long does it take codes to come back, do I need to drive it around or is some idling/revving sufficient?
Only P0300 was showing after a minute or two. https://obdcodelookup.com/dtc/p0300-chevrolet/
Attached a video, foot was off pedal in neutral. This occurred after tapping the gas a bit. https://drive.google.com/drive/folders/1q22CjlRZkaxloz1jxD3-bEz_BT7tOIDf?usp=sharing Video might take a second to upload.
Only P0300 was showing after a minute or two. https://obdcodelookup.com/dtc/p0300-chevrolet/
Attached a video, foot was off pedal in neutral. This occurred after tapping the gas a bit. https://drive.google.com/drive/folders/1q22CjlRZkaxloz1jxD3-bEz_BT7tOIDf?usp=sharing Video might take a second to upload.
- Gtstorey Goblin Guru
The codes will come back when the ECM sees the problem. Go ahead and try and drive it and see what you get. Hard to do much trouble shooting on a random misfire code. It’s strange that this is an additional code from those listed earlier. Still sounds like a general voltage problem to me.
YoungGun
Active Member
- YoungGun Active Member
So you don't think the misfire code is the culprit? Video just uploaded if you want to see what's happening (or half of it) https://drive.google.com/file/d/1qpfmnwaKN05fVPgaQSNizTVSzdL72cAw/view?usp=sharing Listen at 10 seconds >
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YoungGun
Active Member
- YoungGun Active Member
Video should be working now: https://youtube.com/shorts/IOMbVHd6xXg
As well as additional pics: https://drive.google.com/drive/folders/1q22CjlRZkaxloz1jxD3-bEz_BT7tOIDf?usp=sharing
TravMac
Well-Known Member
- TravMac Well-Known Member
I'd have to agree with the others, driving around to figure out if any other codes come back is important. Data will be your friend. Honestly, with a random misfire like that it sounds like you may just need to go back to basics again with the engine: Fuel, Spark, Air.
Reading through everything again it seems most unhappy at low RPM or at a stop in most any given situation. Throttle can cause a limp mode to also act like that, but shouldn't result in misfires. Maybe keep an eye on those codes if they come back, but that is probably a separate issue.
You can try this too. Plug your vacuum line at the throttle body and run manual brakes to see if it's a vacuum leak/bad brake booster. That would help rule out if it's being caused by an air leak particularly when coming to a stop as you've mentioned. Even something small that you wouldn't feel in the brakes could cause a rough idle like that. Plus the brake vacuum circuit has many adapters from the engine to the front where the booster is, so this would eliminate all of those interfaces as a "test". Testing all locations for air leaks is good too, but that's just a big one.
The other idea for startup/low RPM issues could be old/bad fuel. Have you filled up driving it around much yet? Seems like you've put on some miles, but never hurts to check. I know my car isn't happy till it's warmed up on E85 with some random misfires, but I know bad gas can give that same feel too. You'd think a modern gas station would always have good gas, but speaking from experience I've went months figuring out misfire codes all due to one station getting a bad tank. You also did mention running a different octane gas which could also not play nice if aggressively tuned and lead to misfires. You can always order a barrel of what it is tuned for in 5 gallon drums and see if that makes any difference for you.
As always, just thoughts. I'm really curious to see what does the trick with this thing!
Reading through everything again it seems most unhappy at low RPM or at a stop in most any given situation. Throttle can cause a limp mode to also act like that, but shouldn't result in misfires. Maybe keep an eye on those codes if they come back, but that is probably a separate issue.
You can try this too. Plug your vacuum line at the throttle body and run manual brakes to see if it's a vacuum leak/bad brake booster. That would help rule out if it's being caused by an air leak particularly when coming to a stop as you've mentioned. Even something small that you wouldn't feel in the brakes could cause a rough idle like that. Plus the brake vacuum circuit has many adapters from the engine to the front where the booster is, so this would eliminate all of those interfaces as a "test". Testing all locations for air leaks is good too, but that's just a big one.
The other idea for startup/low RPM issues could be old/bad fuel. Have you filled up driving it around much yet? Seems like you've put on some miles, but never hurts to check. I know my car isn't happy till it's warmed up on E85 with some random misfires, but I know bad gas can give that same feel too. You'd think a modern gas station would always have good gas, but speaking from experience I've went months figuring out misfire codes all due to one station getting a bad tank. You also did mention running a different octane gas which could also not play nice if aggressively tuned and lead to misfires. You can always order a barrel of what it is tuned for in 5 gallon drums and see if that makes any difference for you.
As always, just thoughts. I'm really curious to see what does the trick with this thing!
YoungGun
Active Member
- YoungGun Active Member
Thought I'd add in the solution for anyone down the line with a similar problem.
The professional mechanic inspected everything and ran all the tests. Nothing was problematic until he randomly placed his hand on the supercharger inlet and found it to be unusually cold despite haven driven it. He took the throttle body off and meth poured out of it. Cleaned it up, put it back in, disconnected the meth system power, ran great for 30 seconds, then same issue. Took throttle body off again and more meth pooling. Finally completely disconnected the entire meth system so no meth could feed in, problem solved. Apparently meth was running through the system even though it was disconnected by getting sucked in under vacuum. I had noticed that after topping the entire meth reservoir up and only driving it around the block a few times to get trouble codes to pop up, I was already down to like 1/2 the meth in the tank.
I'm not sure why the issue was present before I had even filled the meth up in the first place. I'm certain it was stalling before I plugged meth in unless my memory is fucked.. That was why I put the meth back in in the first place, I thought maybe not using it was causing too much heat buildup and thus issues.
Maybe there was residual meth in the system but I highly doubt that as I don't think Jermey filled it up recently at all. Maybe without meth in the system there was still a vacuum leak caused by the straight tapped meth injection port. I'm not sure why it wasn't present in the test drives except for the fact that we weren't stopping much or going from red light to red light to where the issue would be readily apparent.
TL;DR: Methanol injection port was leaking AKA my Goblin was a meth-addict.
@TheNuker Dare 2 Dream Motorsports is a great shop close by. Extremely fair and nice people.
The professional mechanic inspected everything and ran all the tests. Nothing was problematic until he randomly placed his hand on the supercharger inlet and found it to be unusually cold despite haven driven it. He took the throttle body off and meth poured out of it. Cleaned it up, put it back in, disconnected the meth system power, ran great for 30 seconds, then same issue. Took throttle body off again and more meth pooling. Finally completely disconnected the entire meth system so no meth could feed in, problem solved. Apparently meth was running through the system even though it was disconnected by getting sucked in under vacuum. I had noticed that after topping the entire meth reservoir up and only driving it around the block a few times to get trouble codes to pop up, I was already down to like 1/2 the meth in the tank.
I'm not sure why the issue was present before I had even filled the meth up in the first place. I'm certain it was stalling before I plugged meth in unless my memory is fucked.. That was why I put the meth back in in the first place, I thought maybe not using it was causing too much heat buildup and thus issues.
Maybe there was residual meth in the system but I highly doubt that as I don't think Jermey filled it up recently at all. Maybe without meth in the system there was still a vacuum leak caused by the straight tapped meth injection port. I'm not sure why it wasn't present in the test drives except for the fact that we weren't stopping much or going from red light to red light to where the issue would be readily apparent.
TL;DR: Methanol injection port was leaking AKA my Goblin was a meth-addict.
@TheNuker Dare 2 Dream Motorsports is a great shop close by. Extremely fair and nice people.
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YoungGun
Active Member
- YoungGun Active Member
I believe this is the one (I didn't build the vehicle): https://www.snowperformance.eu/en/water-injection/boost-cooler-stage-1
Desert Sasqwatch
Bigfoot Goblin
- Desert Sasqwatch Bigfoot Goblin
I read back through this entire post and didn't see you stating there was a meth system until this morning's post. That information would have been helpful from the start of this troubleshooting thread and may have gotten this resolved much sooner.
Do you have a check valve in the meth feed line? Snow recommends this if the tank is located higher than the injector location so the siphoning problem doesn't occur.
Do you have a check valve in the meth feed line? Snow recommends this if the tank is located higher than the injector location so the siphoning problem doesn't occur.
YoungGun
Active Member
- YoungGun Active Member
Yah.. woops. I guess I stupidly didn't think that was it since the issue seemed to be present before the system was electrically hooked up and before meth was actually in the system, sorry. The tank seems pretty level, yes it has a check valve.
Bad luck that I cleaned the throttle body prior to filling up the meth system or else I may have noticed this right away too.
Attachments
escapepilot
Goblin Guru
- escapepilot Goblin Guru
Could the check valve have failed? Not familiar with that particular system could a seal have failed or it just be stuck open?
Sparvy
Well-Known Member
- Sparvy Well-Known Member
I've got the aem system so I'm not sure if you have an inline check valve (separate or integral to the injector) or flow shut off solenoid but I'd start by replacing the nozzle and adding an inline solenoid close to the injector to prevent any future siphoning or leaking injector issues.
