Fixed giant vacuum leak, now it doesn't want to idle

I had a hose from a port on the intake manifold to a cannister that I thought was a closed system but turned out it was not, so essentially it was a big vacuum leak. The a/f ratios were good, the car always started and idled nicely but once I plugged that port, the car does not want to idle. I looked at a car with stock hose routing and it normally goes to a solonoid, which in turn is connected to the charcoal cannister. I have a standalone harness with none of the emissions stuff. My theory is that the drive-by-wire throttle acted as it's own idle air control and somehow could deal with the vacuum leak but now that I closed that leak, the throttle body would go to zero opening and the car would stall. To get the car to idle, I changed the Effective Area Minimum (circled) from 0 to 115 and that worked but it seems like a band-aid. Is there a better way to get the car to cold start and idle better? Here are pics of the tune and the port in question.

Attachment 161187

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Originally Posted by marksawatsky

I had a hose from a port on the intake manifold to a cannister that I thought was a closed system but turned out it was not, so essentially it was a big vacuum leak. The a/f ratios were good, the car always started and idled nicely but once I plugged that port, the car does not want to idle. I looked at a car with stock hose routing and it normally goes to a solonoid, which in turn is connected to the charcoal cannister. I have a standalone harness with none of the emissions stuff. My theory is that the drive-by-wire throttle acted as it's own idle air control and somehow could deal with the vacuum leak but now that I closed that leak, the throttle body would go to zero opening and the car would stall. To get the car to idle, I changed the Effective Area Minimum (circled) from 0 to 115 and that worked but it seems like a band-aid. Is there a better way to get the car to cold start and idle better? Here are pics of the tune and the port in question.

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If you want help post a tune and a log.

Either tune it properly, pay some one to tune it properly, or just take the cap back off.

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Originally Posted by marksawatsky

I had a hose from a port on the intake manifold to a cannister that I thought was a closed system but turned out it was not, so essentially it was a big vacuum leak. The a/f ratios were good, the car always started and idled nicely but once I plugged that port, the car does not want to idle. I looked at a car with stock hose routing and it normally goes to a solonoid, which in turn is connected to the charcoal cannister. I have a standalone harness with none of the emissions stuff. My theory is that the drive-by-wire throttle acted as it's own idle air control and somehow could deal with the vacuum leak but now that I closed that leak, the throttle body would go to zero opening and the car would stall. To get the car to idle, I changed the Effective Area Minimum (circled) from 0 to 115 and that worked but it seems like a band-aid. Is there a better way to get the car to cold start and idle better? Here are pics of the tune and the port in question.

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The Idle airflow minimum is where i'd go. but that's assuming a lot of other things. It was likely tuned with a vacuum leak and now that it's plugged the engine needs extra air it wasn't tuned for.

Here is a log and the tuneAttachment 161502Attachment 161503

Tune title indicates its a Camaro and the tune file is for a 06 Vette 7.0L.

I assumed it's a swap with all the stuff turned off.

And you know how people mix and natch parts. No details on what it really is.

Yeah and now with a second thread about some throttle body issues and dead pedal and all the throttle body codes are turned off.

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Originally Posted by 2xLS1

And you know how people mix and natch parts. No details on what it really is.

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Yes, I guess I should have more detail. I bought the whole engine, ecm and pedal out of a wrecked C6 Z06. I installed it all unmodified and unchanged except for the harness. The only change I made to the tune was to turn off codes for the emissions stuff which was missing on the 67 Camaro. It all ran flawlessly, no codes, no problems but the throttle was too spicy so I did make changes to the table for how quickly the throttle opened and the table for desired throttle area maps. After those changes I drove the car for months without a problem then during a burnout before a drag race start, my wife took a video and we noticed some smoke coming out the exhaust. That is when I found that the one port in the intake was essentially vented to free air, and I made the post.

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Originally Posted by edcmat-l1

Yeah and now with a second thread about some throttle body issues and dead pedal and all the throttle body codes are turned off.

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I believe these two issues are unrelated because the idle problem can be reversed just by swapping hoses back

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Originally Posted by marksawatsky

I believe these two issues are unrelated because the idle problem can be reversed just by swapping hoses back

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They're not unrelated. They both are the end result of a jacked up toon.