01-12-2021, 12:34 PM
|
#1
|
|
Registered User
Join Date: Feb 2005
Location: It's a kind of magic.....
Posts: 6,588
|
I'd start pulling the fuel injectors, looking at the tips for carbon fouling.
RKAT is the adaptation value near idle.
FRA is the adaptation value under load and further divided into FRAU (lower load range ) and FRAO (higher load range) ranges (perhaps the durametric doesn't display these divisions).
The RKAT values near idle are used to change the length of the injector pulse to account for deviations from ideality (ie intake leaks) to maintain the proper O2 sensor reading. The RKAT value is an additive factor and can deviate by +/- 4.5%. The FRA value is a multiplicative factor and can deviate by 1.32 to 0.70. The positive values or values greater than 1 increase the injector pulse length to account for a lean mixture, and negative values and values less than 1 are to compensate for a rich mixture.
__________________
“Anything really new is invented only in one’s youth. Later, one becomes more experienced, more famous – and more stupid.” - Albert Einstein
Last edited by JFP in PA; 01-12-2021 at 12:39 PM.
|
|
|
|
01-12-2021, 01:24 PM
|
#2
|
|
Registered User
Join Date: Feb 2020
Location: Coastal NJ
Posts: 71
|
First, thank you both for responding so soon.
Quote:
blue62
Do you still get the P1126 code?
Is it the only code you get?
Any pending codes?
|
P1126 is the only code I get legitimately. When I ran with MAF disconnected I got some codes for the MAF, but not since reconnecting. Also have not gotten P1126 back since first time. No additional pending codes.
Quote:
JFP in PA
I'd start pulling the fuel injectors, looking at the tips for carbon fouling.
RKAT is the adaptation value near idle.
FRA is the adaptation value under load and further divided into FRAU (lower load range ) and FRAO (higher load range) ranges (perhaps the durametric doesn't display these divisions).
The RKAT values near idle are used to change the length of the injector pulse to account for deviations from ideality (ie intake leaks) to maintain the proper O2 sensor reading. The RKAT value is an additive factor and can deviate by +/- 4.5%. The FRA value is a multiplicative factor and can deviate by 1.32 to 0.70. The positive values or values greater than 1 increase the injector pulse length to account for a lean mixture, and negative values and values less than 1 are to compensate for a rich mixture.
|
Great, as soon as it gets warm enough to mess with the plastic window, I'll pull the fuel rail and look at the injectors as I change them.
I guess Durametric tool does not divide further because I do not see FRAU or FRA0.
RKAT values of -2.4 indicates rich at idle and FRA 1.3 (positive) is lean above idle then correct? I was considering smoking the intake again but if it's over-rich at idle, likely unwarranted?
Anything else I should be checking? Thank you for your time!!
|
|
|
|
01-12-2021, 02:32 PM
|
#3
|
|
Registered User
Join Date: Feb 2005
Location: It's a kind of magic.....
Posts: 6,588
|
Quote:
Originally Posted by porschefan76
First, thank you both for responding so soon.
P1126 is the only code I get legitimately. When I ran with MAF disconnected I got some codes for the MAF, but not since reconnecting. Also have not gotten P1126 back since first time. No additional pending codes.
Great, as soon as it gets warm enough to mess with the plastic window, I'll pull the fuel rail and look at the injectors as I change them.
I guess Durametric tool does not divide further because I do not see FRAU or FRA0.
RKAT values of -2.4 indicates rich at idle and FRA 1.3 (positive) is lean above idle then correct? I was considering smoking the intake again but if it's over-rich at idle, likely unwarranted?
Anything else I should be checking? Thank you for your time!!
|
You may be seeing a lean situation because the one or more injectors are carboned up and not delivering a full pulse fuel volume.
__________________
“Anything really new is invented only in one’s youth. Later, one becomes more experienced, more famous – and more stupid.” - Albert Einstein
|
|
|
|
|
01-12-2021, 04:09 PM
|
#4
|
|
Registered User
Join Date: Feb 2020
Location: Coastal NJ
Posts: 71
|
Quote:
Originally Posted by JFP in PA
You may be seeing a lean situation because the one or more injectors are carboned up and not delivering a full pulse fuel volume.
|
OK, this is kind of where I was going when I ordered the replacement fuel injectors, so hopefully, I get some progress there.
One more question, the -8.2 bank 1 camshaft deviation alone should not be enough to cause these hesitation issues etc, should they?
Thank you again.
|
|
|
|
|
01-12-2021, 04:27 PM
|
#5
|
|
Registered User
Join Date: Aug 2018
Location: Woodland Wa
Posts: 1,300
|
Following your issue with interest.
Please post results once you have changed out the injectors.
|
|
|
|
|
01-12-2021, 04:42 PM
|
#6
|
|
Registered User
Join Date: Feb 2020
Location: Coastal NJ
Posts: 71
|
Quote:
Originally Posted by blue62
Following your issue with interest.
Please post results once you have changed out the injectors.
|
Will do. Thank you for your interest and help!
It looks like I might be able to get the top in to service mode this weekend, so hoping to get to the fuel injectors.
|
|
|
|
|
01-16-2021, 04:40 AM
|
#7
|
|
Registered User
Join Date: Mar 2018
Location: Fort Langley
Posts: 253
|
Quote:
Originally Posted by blue62
Following your issue with interest.
Please post results once you have changed out the injectors.
|
Likewise.
My codes are clear after changing out all 4 O2 sensors, but still get lingering short periods of bogging, or lack of power. Have never stalled.
__________________
----------------------------
98 Boxster - Ocean Blue metallic. Bringing it back to life and having fun doing it!
20 Harley Streetbob -
|
|
|
|
|
01-16-2021, 07:33 AM
|
#9
|
|
Registered User
Join Date: Feb 2020
Location: Coastal NJ
Posts: 71
|
Wow, this community is awesome. Thank you all for continuing to follow along and helping. I've currently got my heater running in my garage trying to break it into the 50's so I can get some work done today.
Quote:
Originally Posted by Zzorro
Likewise.
My codes are clear after changing out all 4 O2 sensors, but still get lingering short periods of bogging, or lack of power. Have never stalled.
|
I've got my Durametric data and it appears that my pre-cat O2 sensors are working as intended. I'm fairly certain my post-cat are working properly as well, as they maintain a steady mV reading at idle, but they do change as the revs change. So, I haven't considered changing those yet, but might be something I'll do if it's recommended. Again, I've got my data and plots if anyone wants to dig in, but this is not my profession, so I only know what I've read about this data/plots.
Quote:
Originally Posted by Brian Minson
|
I actually make reference to your video in my OP. They were very helpful and helped clarify things when I checked for fuel pump volume and fuel regulator pressure checks, so thank you! I was really hoping my problem was fuel pressure as it has a tendency to backfire into the intake and lope similar to your car in the video when it's cold, but not when warmed up.
I'm really hoping replacing the fuel injectors gives some results, because after that, I'm not even sure which animal to chase next. As I mentioned above, my bank 1 camshaft deviation is out of spec, but not enough to throw a code, so I am not sure if that is contributing to the issue or not.
|
|
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is On
|
|
|
All times are GMT -8. The time now is 08:40 AM.
| |
Hybrid Mode
