Idle Issues

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ThatKevin
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Idle Issues

Post by ThatKevin » Sun May 12, 2013 3:27 pm

So, for those that don't follow my progress log, I recently had an engine/tranny/turbo swap done.

Details:
Fully built, low comp bottom end
gasket matched, RT head
Crane 007 cam / springs (on stock cam gear)

The car is running right now on stock ecu and injectors. Megasquirt has been wired in but it is not plugged in. The issue is that it won't idle properly, it'll go up and down between 300 - 2k rpm. It only does this after warming up for a minute or so, before that it idles fine. It's also idling stupid rich... There are no vacuum leaks, and the IAC works fine.

Here is a video of it

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Here's a video of it idling without the MAP sensor plugged in. Seems to idle just fine (let it run for 10 minutes).

Image
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'02 Chrysler Neon RT - SOHC 50trim+Crane 007 ---DEAD---
'05 Dodge Neon SRT4 - DSP & bolt ons ---SOLD---
'08 Dodge Caliber SRT4 - MS1Kv3
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Johny
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Post by Johny » Sun May 12, 2013 3:45 pm

Since he has a bigger cam but running the stock gear, wouldn't that cause an issue since you have to retard the timing?
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ZeroChad
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Post by ZeroChad » Sun May 12, 2013 4:10 pm

Megasquirt has been wired in but it is not plugged in
There yer problem.
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ThatKevin
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Post by ThatKevin » Sun May 12, 2013 4:46 pm

ZeroChad wrote:
Megasquirt has been wired in but it is not plugged in
There yer problem.
Why though?


Also, why is it that it won't idle properly but as soon as the MAP sensor is unplugged it does. MS doesn't share the same MAP sensor as the stock ecu
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'02 Chrysler Neon RT - SOHC 50trim+Crane 007 ---DEAD---
'05 Dodge Neon SRT4 - DSP & bolt ons ---SOLD---
'08 Dodge Caliber SRT4 - MS1Kv3
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gilly02le
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Post by gilly02le » Mon May 13, 2013 12:13 pm

probably unrelated, but your lights seem to dim like crazy at idle, and brighten back up noticeably once the car is revved up, bad grounds?
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Hudson_Neon
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Post by Hudson_Neon » Mon May 13, 2013 12:15 pm

because your stock computer isn't designed to run this...

Fully built, low comp bottom end
gasket matched, RT head
Crane 007 cam / springs (on stock cam gear)

ThatKevin
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Joined: Wed Aug 03, 2011 12:48 pm
Location: Brampton, ON

Post by ThatKevin » Mon May 13, 2013 7:21 pm

Hudson_Neon wrote:because your stock computer isn't designed to run this...
Why is it that it runs perfectly fine with no map sensor then?
gilly02le wrote:probably unrelated, but your lights seem to dim like crazy at idle, and brighten back up noticeably once the car is revved up, bad grounds?
probably because it's almost stalling out
Image
'02 Chrysler Neon RT - SOHC 50trim+Crane 007 ---DEAD---
'05 Dodge Neon SRT4 - DSP & bolt ons ---SOLD---
'08 Dodge Caliber SRT4 - MS1Kv3
Progress Log

ZeroChad
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Post by ZeroChad » Mon May 13, 2013 7:35 pm

Are you sure it runs perfectly? I doubt it. What AFR are you reading while unplugged? I can't remember if the stock ecu will go into open loop when the map is unplugged, but I think it will. Most likely you are running crazy rich.

Large cams like the 005 and 007 have overlap which allows unburnt fuel to potentially enter the exhaust system. This will cause screwy readings with your O2. Tuning for idle can be a huge PITA because of this.
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2002 - Neon SE Fully Built (scrapped)

ThatKevin
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Location: Brampton, ON

Post by ThatKevin » Mon May 13, 2013 7:39 pm

ZeroChad wrote:Are you sure it runs perfectly? I doubt it. What AFR are you reading while unplugged? I can't remember if the stock ecu will go into open loop when the map is unplugged, but I think it will. Most likely you are running crazy rich.

Large cams like the 005 and 007 have overlap which allows unburnt fuel to potentially enter the exhaust system. This will cause screwy readings with your O2. Tuning for idle can be a huge PITA because of this.
unplugged map, AFR was 14.9-15.2 while idling

just because it's unplugged it limits to 4k rpm
Image
'02 Chrysler Neon RT - SOHC 50trim+Crane 007 ---DEAD---
'05 Dodge Neon SRT4 - DSP & bolt ons ---SOLD---
'08 Dodge Caliber SRT4 - MS1Kv3
Progress Log

ThatKevin
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Posts: 1176
Joined: Wed Aug 03, 2011 12:48 pm
Location: Brampton, ON

Post by ThatKevin » Wed May 15, 2013 9:53 pm

SHE IDLES!

Image

I don't know why you guys said it wouldn't............

Ended up being the upstream o2 sensor. Was doused with coolant when I had the leak on the previous head and was reading wacky.

Everything's good now, just waiting on a tune.
Image
'02 Chrysler Neon RT - SOHC 50trim+Crane 007 ---DEAD---
'05 Dodge Neon SRT4 - DSP & bolt ons ---SOLD---
'08 Dodge Caliber SRT4 - MS1Kv3
Progress Log

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