Why do I have high negative fuel trims?
03-10-2013, 05:37 PM
#26
You want to keep the idle below 1000...it is best to multiply all the idle tables by a constant to raise them to around 950...not put in a flatline 1000 for all the values...it works better.
If you go to 1000 or above and the load is skewed by your MAF and or Load values then it will put you into a timing area that alters things dramatically from idle.
Search around on the dwell thing...there is a much better table around that is better than the *1.45 thing
What's the max rpm 5000 thing?
If you go to 1000 or above and the load is skewed by your MAF and or Load values then it will put you into a timing area that alters things dramatically from idle.
Search around on the dwell thing...there is a much better table around that is better than the *1.45 thing
What's the max rpm 5000 thing?
03-11-2013, 03:50 PM
#27
Driving my unreliable rx8
Thread Starter
ok, So I'll try bringing the Idle to 950, And I'll change it all as a percentage to make it gradually step down.
I've been over the thread by Oltmann on dwell and like it I was just being cauious. I saw a lot more about people using 1.45 instead of his Table, but I really liked the looks of tables he and Team RX8 were talking about.
And 5000 RPM Limit is because it was recently rebuilt and I tend to bounce it off the rev limiter a lot so that keeps the engine speed down so It can have a little break in time. I have about 300 miles on it now.
I've been over the thread by Oltmann on dwell and like it I was just being cauious. I saw a lot more about people using 1.45 instead of his Table, but I really liked the looks of tables he and Team RX8 were talking about.
And 5000 RPM Limit is because it was recently rebuilt and I tend to bounce it off the rev limiter a lot so that keeps the engine speed down so It can have a little break in time. I have about 300 miles on it now.
03-11-2013, 04:16 PM
#28
I would raise the rpm limit back closer to normal and be careful you don't over-rev it
A lot of the tables have consequences that aren't first apparent...and because we have basically learned by trial and error...that could be an issue as well. I have never tried to lower it that much
A lot of the tables have consequences that aren't first apparent...and because we have basically learned by trial and error...that could be an issue as well. I have never tried to lower it that much
03-11-2013, 07:30 PM
#29
If you went through your wiring harness like that---thats was above and beyound the usual--hats off to you dude!
I found my basic problem!
My air intake temps were too low. When I tuned the ambient temps were in the 70-80f.
Lately the ambients have been in the 50-60's.My iat reads the same as ambient. Old logs show the iats was in the 80's.
So --today ambients were in the 70's--and stft's are back to normal.
Seriously that made a big difference.
I never knew my iat was that sensitive. I need to speak with my tuner. Or perhaps my maf just needs replacing.
Sorry to clog up your thread here --but I thought it may be a little help?
I found my basic problem!
My air intake temps were too low. When I tuned the ambient temps were in the 70-80f.
Lately the ambients have been in the 50-60's.My iat reads the same as ambient. Old logs show the iats was in the 80's.
So --today ambients were in the 70's--and stft's are back to normal.
Seriously that made a big difference.
I never knew my iat was that sensitive. I need to speak with my tuner. Or perhaps my maf just needs replacing.
Sorry to clog up your thread here --but I thought it may be a little help?
03-11-2013, 11:28 PM
#30
Driving my unreliable rx8
Thread Starter
Heck no, Clog it up. Any Ideas are appreciated. I've learened a lot reading all ya'lls old threads.
I am going to try the next Ideas from Dannobre, I'll probably make a few maps from them. One with just the Limiter raised and one with the Idle brought down and limiters raised.
It is kind of a fine balancing act between what to adjust. We don't really know what it is causing the LTFT to be off. It can be so many things and our only two major places to change them are MAF and Injectors.(I think)
If you scaled Injectors when you should have scaled MAF, That could lead to your problem. Because your injector flow should not change dramaticaly at different temps maybe a percent or two.
Where Your MAF will change quite a bit with Tempeture. So maybe you would need to take from one and give to the other to get it more accurate.
The only reason I am thinking about it that hard is I have scaled my injectors up 15% to get my trims down and I think it was probably too far. So If I get a Kind of stable tune, When the weather changes I might have the same issue and have to account for it. It's been in the 30-50F Range but summer is coming and it will be 100-110F
I am going to try the next Ideas from Dannobre, I'll probably make a few maps from them. One with just the Limiter raised and one with the Idle brought down and limiters raised.
It is kind of a fine balancing act between what to adjust. We don't really know what it is causing the LTFT to be off. It can be so many things and our only two major places to change them are MAF and Injectors.(I think)
If you scaled Injectors when you should have scaled MAF, That could lead to your problem. Because your injector flow should not change dramaticaly at different temps maybe a percent or two.
Where Your MAF will change quite a bit with Tempeture. So maybe you would need to take from one and give to the other to get it more accurate.
The only reason I am thinking about it that hard is I have scaled my injectors up 15% to get my trims down and I think it was probably too far. So If I get a Kind of stable tune, When the weather changes I might have the same issue and have to account for it. It's been in the 30-50F Range but summer is coming and it will be 100-110F
03-12-2013, 06:25 PM
#34
an interesting fact about idle stft's--i can lock my ssv open and it doesnt affect my stft's at all. I will pull 8 -9 grams per sec at 1.2Krpms regardless. Now I am sc'ed so the engines access to air is easier--even when not in boost.
But if you think about it--the engine will only pull in so much air at idle regardless of the port size. Now the intake velocity may be changed and therefore the actual combustion efficiency could be affected, but at idle the amount of air coming in should not be affected ported or not.
porting will only come into play (airflow mass) once a large volume of air is required. Idle and normal driving usually are not affected?
yea-- i here you about the scaling---thats why I thought i had a leaking injector or sumthing.
But, now i do wonder if it is the maf versus the tune needs touching up.
Good thread.
I wish I had all the tools I need to do a proper diag
But if you think about it--the engine will only pull in so much air at idle regardless of the port size. Now the intake velocity may be changed and therefore the actual combustion efficiency could be affected, but at idle the amount of air coming in should not be affected ported or not.
porting will only come into play (airflow mass) once a large volume of air is required. Idle and normal driving usually are not affected?
yea-- i here you about the scaling---thats why I thought i had a leaking injector or sumthing.
But, now i do wonder if it is the maf versus the tune needs touching up.
Good thread.
I wish I had all the tools I need to do a proper diag
03-12-2013, 10:51 PM
#35
Driving my unreliable rx8
Thread Starter
I Agree sir.
The engine can only hold 80 Cubic inches of Air. Porting does not make it hold more. Thats what FI is for.
Porting makes it easier to breath. so When you get into High RPM at WOT It will have less vacuum. And With FI It should reduce back pressure allowing more pressure into the Chamber
That leads to a thought. Where are people sampling their pressure and Vacuum from.
I think the best place would be the Lower intake manifold ports. Because it's the closest to the rotors.
The engine can only hold 80 Cubic inches of Air. Porting does not make it hold more. Thats what FI is for.
Porting makes it easier to breath. so When you get into High RPM at WOT It will have less vacuum. And With FI It should reduce back pressure allowing more pressure into the Chamber
That leads to a thought. Where are people sampling their pressure and Vacuum from.
I think the best place would be the Lower intake manifold ports. Because it's the closest to the rotors.
03-13-2013, 11:13 AM
#37
Driving my unreliable rx8
Thread Starter
Dan, I understand that, I just feel like there is another factor in there for fuel trims to be off by over 10%.
If my injectors were wired wrong, I would be getting more like -22 by my calculations. I will be double checking them when I get home.
It really makes me think my injector with 138,000 Miles are just a little worn out.(too bad I still have not received the flow test from Feb 17th)
I'll be adjusting the limiter and Idle when I get home also and giving it a try in a few different ways.
Dont take anything I've stated as trying to know what I am doing. I'm just trying to put reason to what it is doing and the suggections. If my reasoning is wrong please feel free to point it out.
If my injectors were wired wrong, I would be getting more like -22 by my calculations. I will be double checking them when I get home.
It really makes me think my injector with 138,000 Miles are just a little worn out.(too bad I still have not received the flow test from Feb 17th)
I'll be adjusting the limiter and Idle when I get home also and giving it a try in a few different ways.
Dont take anything I've stated as trying to know what I am doing. I'm just trying to put reason to what it is doing and the suggections. If my reasoning is wrong please feel free to point it out.
03-14-2013, 01:18 PM
#38
Driving my unreliable rx8
Thread Starter
I Raised my limiter back to 9K, and drove 20 miles, (I have a nice almost deserted twisty road that loops back to my house. Some 10 MPH curves up to a 60 MPH road.
The Idle problem I am having is When it starts once IT hits 108-110F It starts hunting from 500 to 1500 RPM then Dies
Map 1
Limiter 9K
Fans Lowered
Dwell * 1.45
Idle 1000
After after getting home I let it cool off again and still no bueno. IT won't Idle. I Went to map two
Map 2
Limiter 9K
Dwell 1.45
Idle Stock
Drove 20 miles, Let car cool, Started it up and no Idle.
Map 3
Stock
Drove 20 miles, Let car cool, Started it up and no Idle
Map 4
Stock, With
Closed loop exit RPM 200
Started the car from cold and It ides great, drove it and it is great, but my AFR's are off.
The Idle problem I am having is When it starts once IT hits 108-110F It starts hunting from 500 to 1500 RPM then Dies
Map 1
Limiter 9K
Fans Lowered
Dwell * 1.45
Idle 1000
After after getting home I let it cool off again and still no bueno. IT won't Idle. I Went to map two
Map 2
Limiter 9K
Dwell 1.45
Idle Stock
Drove 20 miles, Let car cool, Started it up and no Idle.
Map 3
Stock
Drove 20 miles, Let car cool, Started it up and no Idle
Map 4
Stock, With
Closed loop exit RPM 200
Started the car from cold and It ides great, drove it and it is great, but my AFR's are off.
03-14-2013, 08:18 PM
#40
Driving my unreliable rx8
Thread Starter
I thought I heard you
Ok I went below 950. I'll try another at 950
I know you told me not to play with the auxilery tables, But I am using this as a referance. It idles great in open loop with nothing else changed.
Is there different timing maps for open loop and closed loop? If it's all one map then timing should not be my issue.
In open loop it is still calculating load and fueling based on load. It just does not adjust to make the AFR correct. Is this right?
In closed loop it uses STFT to do the minor changes and It develops LTFT for anything that is consistent. Then the ECU uses LTFT when in open loop so it will be Closer to the Desired AFR.
I still need another WB02 sensor to plug in and see if I'm getting the same results. Maybe a MAF also, but I bought that at Autozone so I can just bring it back for another and see if I'm getting the same results.
I would raise the rpm limit back closer to normal and be careful you don't over-rev it
A lot of the tables have consequences that aren't first apparent...and because we have basically learned by trial and error...that could be an issue as well. I have never tried to lower it that much
A lot of the tables have consequences that aren't first apparent...and because we have basically learned by trial and error...that could be an issue as well. I have never tried to lower it that much
Is there different timing maps for open loop and closed loop? If it's all one map then timing should not be my issue.
In open loop it is still calculating load and fueling based on load. It just does not adjust to make the AFR correct. Is this right?
In closed loop it uses STFT to do the minor changes and It develops LTFT for anything that is consistent. Then the ECU uses LTFT when in open loop so it will be Closer to the Desired AFR.
I still need another WB02 sensor to plug in and see if I'm getting the same results. Maybe a MAF also, but I bought that at Autozone so I can just bring it back for another and see if I'm getting the same results.
Last edited by logalinipoo; 03-14-2013 at 08:27 PM.
03-14-2013, 09:19 PM
#41
Is there different timing maps for open loop and closed loop?
Hard to say...because we can't see most of them
There are lot of tables and maps that the Cobb doesn't address.....In open loop it is still calculating load and fueling based on load. It just does not adjust to make the AFR correct. Is this right?
It is likey running very rich in open loop...that is likely what is making it run... What are your AFR's at idle with the car in open loop? How does it idle with the WBO2 disconnected?
In closed loop it uses STFT to do the minor changes and It develops LTFT for anything that is consistent. Then the ECU uses LTFT when in open loop so it will be Closer to the Desired AFR.
After you reset the ECU..you will have no LTFT..so you will have no adjustments...it will run off the STFT until it sets LTFT..usually in a drive cycle
I still need another WB02 sensor to plug in and see if I'm getting the same results. Maybe a MAF also, but I bought that at Autozone so I can just bring it back for another and see if I'm getting the same results.
Try a map that has dwell, fans and idle bumped up to 940-50 and see what happens....What is the AFR when the IAT's are warm and it doesn't idle? What is the idle vac at that temperature?
03-14-2013, 09:54 PM
#42
Driving my unreliable rx8
Thread Starter
Yes it does run rich. It runs at 12.5 Which is 15% off that I've been dealing with. 14.7*0.85=12.495
"After you reset the ECU..you will have no LTFT..so you will have no adjustments...it will run off the STFT until it sets LTFT..usually in a drive cycle"
Yes, that is what I was refering to. I realize that by locking it into open loop it will never develop fuel trims.
Idle jumps soo much I can not tell the Vac.
Currently it is 60F, In the open loop map I have AFR of 12.5 I will go get a log in the open loop map, and the vac is 8.2 to 8.6 PSI.
Then build another using oltmans dwell settings, your Idle 940-950, and fans at 190 and 195 off at 180.
"After you reset the ECU..you will have no LTFT..so you will have no adjustments...it will run off the STFT until it sets LTFT..usually in a drive cycle"
Yes, that is what I was refering to. I realize that by locking it into open loop it will never develop fuel trims.
Idle jumps soo much I can not tell the Vac.
Currently it is 60F, In the open loop map I have AFR of 12.5 I will go get a log in the open loop map, and the vac is 8.2 to 8.6 PSI.
Then build another using oltmans dwell settings, your Idle 940-950, and fans at 190 and 195 off at 180.
04-07-2013, 11:50 PM
#43
Driving my unreliable rx8
Thread Starter
I got her fixed this week but I broke my computer so I was offline for a few days.
I guess I am a little color blind. I had my Rear primary and P2 wires crossed.
Now it is running great on a stock tune. Now If I can get togther with Mazdamaniac for a tune I'll be good.
Thanks for the help
I guess I am a little color blind. I had my Rear primary and P2 wires crossed.
Now it is running great on a stock tune. Now If I can get togther with Mazdamaniac for a tune I'll be good.
Thanks for the help
04-21-2013, 10:27 PM
#44
I got her fixed this week but I broke my computer so I was offline for a few days.
I guess I am a little color blind. I had my Rear primary and P2 wires crossed.
Now it is running great on a stock tune. Now If I can get togther with Mazdamaniac for a tune I'll be good.
Thanks for the help
I guess I am a little color blind. I had my Rear primary and P2 wires crossed.
Now it is running great on a stock tune. Now If I can get togther with Mazdamaniac for a tune I'll be good.
Thanks for the help
04-21-2013, 10:54 PM
#45
Driving my unreliable rx8
Thread Starter
Here is the wiring that I used origionaly posted by ROT8 The color on the exposed wires was really faded when I cut back the tape it was very clear that I had a green and blue wire corssed.
Fuel Rail 1 (two injectors)
Both leads for this fuel rail come off of the main harness together.
Front rotor injector wire color is light-green and red. (Front Primary 1)
Front injector Wire lead has White colored tape
Rear rotor injector wire color is light-green and black. (Rear Primary 1)
Rear injector Wire lead has Tan colored tape.
Fuel Rail 2 (four injectors)
The two center (the middle) injector wires come off the harness together and split.
Front side of the middle split has Yellow colored tape.
Rear side of the middle split has Green colored tape.
The two end (front and rear) injector wires come off the harness separately and have no colored tape.
The front injector wire is Green and Red. (Front Secondary)
The front rotor middle injector wire is Black and Blue. (Front Primary 2)
The rear rotor middle injector wire is White and Green. (Rear Primary 2)
The rear injector wire is Black and Blue. (Rear Secondary)
Fuel Rail 1 (two injectors)
Both leads for this fuel rail come off of the main harness together.
Front rotor injector wire color is light-green and red. (Front Primary 1)
Front injector Wire lead has White colored tape
Rear rotor injector wire color is light-green and black. (Rear Primary 1)
Rear injector Wire lead has Tan colored tape.
Fuel Rail 2 (four injectors)
The two center (the middle) injector wires come off the harness together and split.
Front side of the middle split has Yellow colored tape.
Rear side of the middle split has Green colored tape.
The two end (front and rear) injector wires come off the harness separately and have no colored tape.
The front injector wire is Green and Red. (Front Secondary)
The front rotor middle injector wire is Black and Blue. (Front Primary 2)
The rear rotor middle injector wire is White and Green. (Rear Primary 2)
The rear injector wire is Black and Blue. (Rear Secondary)
04-22-2013, 08:10 PM
#50
https://www.rx8club.com/trouble-shoo...nector-209685/
This helped me and mine were crossed!!! Thanks for figuring this out. I have been hunting this problem down for a year!!! Your awesome!!
This helped me and mine were crossed!!! Thanks for figuring this out. I have been hunting this problem down for a year!!! Your awesome!!