 AFR reading lean, AFR table showing rich..., guessing an exhaust leak? Other options? |
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| VaccaRabite |
 Jun 14 2019, 04:05 PM
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En Garde!  Group: Admin Posts: 13,821 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region 
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As I get closer to Dyno Day for my 914 (July 22), I have a theory about some of my drivability issues.
This car has modern EFI, not carbs or Djet/Ljet. It’s running MS2 through a Microsquirt controller. The car is clearly very rich. It bogs heavily coming off idle, to the point that it will sometime stall out if you don't dance the accelerator pedal just right at a stop sign or a traffic light. Last oil change I could also smell gas in the oil. And while Bob Hill ( @saigon71 )was driving my car the other night I occasionally saw puffs coming out of the muffler on overrun. Kinda cool, in a way, but not great.... lol. I hooked up my trusty ancient tuning laptop and opened up the AFR table while looking at the AFR meter. Where the table is showing ~13, the gauge was swinging ~15.5, especially just off idle, when the car got hot. So my theory is that the ECU is reacting to a false LEAN condition and dumping huge amount of gas into an already rich environment. So, my possibilities are:
@Eric_Shea @Mark_Henry @chrisfoley Thoughts? Zach |
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| ChrisFoley |
Jun 17 2019, 07:08 AM
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I am Tangerine Racing Group: Members Posts: 8,016 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None
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Are you sure the system is running closed loop when it's showing lean?
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| VaccaRabite |
Jun 17 2019, 07:30 AM
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#3
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En Garde! Group: Admin Posts: 13,821 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region
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QUOTE(ChrisFoley @ Jun 17 2019, 09:08 AM)  Are you sure the system is running closed loop when it's showing lean? No. And if the ECU isn't set to use the AFR to add or pull fuel my theory is blown. I should have checked that last night while I had the tuning laptop up. I've been working on the assumption that its. Zach |
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Posts in this topic
VaccaRabite AFR reading lean, AFR table showing rich... Jun 14 2019, 04:05 PM
Mark Henry What WB do you have?
How old is the lambda? 4.2 or... Jun 14 2019, 07:13 PM
Mark Henry dp- Jun 14 2019, 07:16 PM wndsrfr
As I get closer to Dyno Day for my 914 (July 22),... Jun 15 2019, 05:53 AM Mark Henry
First step is to replace and properly calibrate... Jun 15 2019, 06:11 AM VaccaRabite The O2 bung is in the pipe between the cans on my ... Jun 15 2019, 08:35 AM VaccaRabite The Wideband is an AEM 30-2310
The wiring was done... Jun 16 2019, 06:21 PM VaccaRabite I recalibrated the AFR EGO, burned it to the ECU a... Jun 16 2019, 07:27 PM rhodyguy What do the plugs look like? Do each of the throat... Jun 16 2019, 08:48 PM VaccaRabite
What do the plugs look like? Do each of the throa... Jun 17 2019, 06:34 AM Mark Henry
Are you sure the system is running closed loop wh... Jun 17 2019, 07:28 AM crash914 I have a spare AEM and controller along with a cou... Jun 17 2019, 12:34 PM VaccaRabite Well, my theory was somewhat dashed yesterday afte... Jun 18 2019, 07:14 AM Mark Henry Where is the Lambda mounted?
I've measured a h... Jun 18 2019, 08:38 AM VaccaRabite
Where is the Lambda mounted?
I've measured a ... Jun 18 2019, 10:29 AM Mark Henry C&P from 14point7
If your lambda is too coo... Jun 18 2019, 12:14 PM VaccaRabite
C&P from 14point7
If your lambda is too co... Jun 19 2019, 06:40 PM |
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