DIYPNP throttle tip-in rich enough to bog, and lift goes super lean
#1
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Join Date: Dec 2008
Location: Ft. Lauderdale, FL
Posts: 315
Total Cats: 9
DIYPNP throttle tip-in rich enough to bog, and lift goes super lean
I have made zero changes to the car, but the car is so rich on throttle tip-in that it reads in the 10AFR range and hesitates slightly. Also, I have noticed that when I lift (i.e. coasting) I am getting super lean readings, like 30AFR range. Where would you start looking for the issue, other than a log, I will get a log of the events and upload them as soon as I can.
Background:
1990 Miata
'01+ VVT engine
DIYPNP
VVTuner running the VVT
Toyota COP's
'01+ "Purple" injectors running @ 60psi
Current MSQ:
2014-04-18_16.37.58.msq
Background:
1990 Miata
'01+ VVT engine
DIYPNP
VVTuner running the VVT
Toyota COP's
'01+ "Purple" injectors running @ 60psi
Current MSQ:
2014-04-18_16.37.58.msq
#8
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Join Date: Nov 2008
Location: Tampa, Florida
Posts: 21,026
Total Cats: 3,123
Coasting is called overrun. Your injectors will be turned off completely during overrun to conserve fuel and aid with engine braking. This is normal and desirable.
As Brain said, adjust your accel enrichments lower and possibly to taper more quickly as well.
As Brain said, adjust your accel enrichments lower and possibly to taper more quickly as well.
#9
Junior Member
Thread Starter
Join Date: Dec 2008
Location: Ft. Lauderdale, FL
Posts: 315
Total Cats: 9
Thank you for all your responses.
I just wanted to add that I have been running this set-up for the past two years and it seems like just overnight, I have been having these issues. This is not a new set-up, this is not a change I made to any maps.
Brain, thanks for your hard work... but Jesus ******* Christ... take a chill pill.
I am wondering if I am getting an issue with the Cam sensor or something that has just popped up that would point to this issue. I know this is hard to diagnose without a log, I will have one posted tonight.
I just wanted to add that I have been running this set-up for the past two years and it seems like just overnight, I have been having these issues. This is not a new set-up, this is not a change I made to any maps.
Brain, thanks for your hard work... but Jesus ******* Christ... take a chill pill.
I am wondering if I am getting an issue with the Cam sensor or something that has just popped up that would point to this issue. I know this is hard to diagnose without a log, I will have one posted tonight.
#16
You're hitting the throttle, TPS accel turns on, commands a bunch of pulsewidth, and it goes rich. Looks like a pretty clear cut case of too much AE. No idea why it would change overnight, though. Try lowering it.
Your TPS spends a lot of time at -1. Might want to re calibrate it.
There's also an area in the 18_7_02 log where your spark advance, MAP, and RPM are oscillating while TPS is at -1. Is this you trying to idle? either way, look into the fueling/spark for the cells near 1-1.6k rpm, something is not right.
Those are my thoughts.. good luck
Your TPS spends a lot of time at -1. Might want to re calibrate it.
There's also an area in the 18_7_02 log where your spark advance, MAP, and RPM are oscillating while TPS is at -1. Is this you trying to idle? either way, look into the fueling/spark for the cells near 1-1.6k rpm, something is not right.
Those are my thoughts.. good luck
#17
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Thread Starter
Join Date: Dec 2008
Location: Ft. Lauderdale, FL
Posts: 315
Total Cats: 9
Thanks, for the information. I will take a look at the TPS AE, when I looked at the curves, they still match the previous curves from before this issue started. Yes, the oscillations are trying to return to idle and that area needs work still, but it's a Racecar so idle quality has taken a back-seat. Once fully warm the idle returns and stays pretty close to 1000rpms.
Way back when I swapped the VVT motor in, I was having an issue with throttle hang, and I set the TPS to -1 by calibrating it and then adjusting the the value to ensure that it was returning to 0. I need to re-calibrate it, I just forgot to do that once I got the throttle hang fixed.
Way back when I swapped the VVT motor in, I was having an issue with throttle hang, and I set the TPS to -1 by calibrating it and then adjusting the the value to ensure that it was returning to 0. I need to re-calibrate it, I just forgot to do that once I got the throttle hang fixed.
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