Power FC exhaust popping w/ airpump, during decel
02-22-04, 10:58 PM
#1
94 FD, 69 Datsun Roadster
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exhaust popping w/ airpump, during decel
I had the FD tuned this weekend. The car is smooth and powerful. Only one issue, which seems to be a common PFC issue:
At 2-3k rpms when going off throttle (decel) slowly, there was some exhaust popping. If I lifted off throttle abruptly, there was no popping. Steve lowered the fuel, changed the decel settings and even calibrated the TPS (1.16 warm IIRC). No improvement. He was able to stop the popping by unplugging the airpump. This will work, but I want to run my airpump. I don't want popping as I drive through my neighborhood or in parking lots. Anyone have another solution for this problem?
TIA,
Chris
94 FD: 20k mile stock motor & twins, M2 intake, SMIC, 850s all around, hiflow cat & RB catback
At 2-3k rpms when going off throttle (decel) slowly, there was some exhaust popping. If I lifted off throttle abruptly, there was no popping. Steve lowered the fuel, changed the decel settings and even calibrated the TPS (1.16 warm IIRC). No improvement. He was able to stop the popping by unplugging the airpump. This will work, but I want to run my airpump. I don't want popping as I drive through my neighborhood or in parking lots. Anyone have another solution for this problem?
TIA,
Chris
94 FD: 20k mile stock motor & twins, M2 intake, SMIC, 850s all around, hiflow cat & RB catback
02-27-04, 12:30 AM
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Clearly I am new to the Rx7 and am only talking in general as I have been a drive-ability tech for 20 years and now own a FD.
The pump is adding 02 to your de-cell mixture and igniting it, disconnected it does not pump extra 02.
There is clearly extra fuel on that type of DE-cell your doing at this time. If you have a de-cell dash pot on the throttle body it may need to be adjusted. You could go leaner on de-cell map. John
The pump is adding 02 to your de-cell mixture and igniting it, disconnected it does not pump extra 02.
There is clearly extra fuel on that type of DE-cell your doing at this time. If you have a de-cell dash pot on the throttle body it may need to be adjusted. You could go leaner on de-cell map. John
02-27-04, 12:57 PM
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94 FD, 69 Datsun Roadster
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cewrx7r1 responded:
Go to the rpm setting menu:
Rev limit 8000 or higher.
The three FC(fuel cuts) should not be higher than 1400.
I use 1200 for all three.
Idle A-E 800
Idle E/L 850
Idle A/C 900
For emissions testing set them down by 50.
That all I can do without being there.
...
For cold start stalling:
Go to the water temp corrections menu for engine warmup, not the cranking menu:
50C first column 1.25
30C first column 1.37
Go to the rpm setting menu:
Rev limit 8000 or higher.
The three FC(fuel cuts) should not be higher than 1400.
I use 1200 for all three.
Idle A-E 800
Idle E/L 850
Idle A/C 900
For emissions testing set them down by 50.
That all I can do without being there.
...
For cold start stalling:
Go to the water temp corrections menu for engine warmup, not the cranking menu:
50C first column 1.25
30C first column 1.37
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