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Flex Fuel Tuning for Pump Gas
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I was out logging today re-calibrating the MAF with new flex fuel sensor enabled running 10%.
Satisfied with the new MAF calibration I re-enabled SD and LTFTs. Afterwards I experienced a fuel pump failure, fuel pump has always been reliable, never happened in the past, don't know if re-enabling SD and LTFTs might somehow be related?
(See Attached MAF and SD screen shots)
Note: intermittent fuel pump failure occurred once during a low power acceleration, approx 2/10s duration, normal pump operation quickly recovered. I also checked the log for any misfires and/or timing issues, negative.
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Satisfied with the new MAF calibration I re-enabled SD and LTFTs. Afterwards I experienced a fuel pump failure, fuel pump has always been reliable, never happened in the past, don't know if re-enabling SD and LTFTs might somehow be related?
(See Attached MAF and SD screen shots)
Note: intermittent fuel pump failure occurred once during a low power acceleration, approx 2/10s duration, normal pump operation quickly recovered. I also checked the log for any misfires and/or timing issues, negative.
I tried, but it did not seem to make a difference. In gear coming to a stop I'm at 1000rpm idle, coasting in neutral 1200rpm until at zero 'stop' speed, then down to pre-set 750rpm idle.
•Manual Trans
•2 Bar OS
(see attached images)
Attachments
ok yea it can be tricky as i dont think we have the direct tables found in the ecu to adjust it so have to find other ways, what u can try is the area scaler ''max percent'' lower that say .5% at a time see if it helps or if not then try the percent max brake, its one of those will allow that much more TB area from idle its like a hard limit, with the manual it can be tricky when ur in neutral but rolling it is different to clutch in rolling, the brake percent may be when ur clutch in and on the brakes stopped and the percent max when ur neutral and maby rolling u will just have to test,
if that dosnt do much the max fail thats at 200 u can lower that but that one is a overall hard stop so what i usually do is lower that one so i still get commanded winter cold start rpm and it will cap it from going above that, but if u go too low on that one it will limit the cold start TB opening, if u get the max fail and those percent max/brake all setup right the idle should be kept within those barriers and u then use the idle controls to control it within there, also the ''min rpm ref'' u have set to 750 just make that 600 so its lower then your commanded idle as that one its like a limit for idle corrections so if u go below it it wont correct the idle,
also see what your idle spark is at then in neutral and rolling see if its in the idle table or mains spark table or coastdown spark table and adjust the spark lower if its in the coastdown table can help, if its in the main spark table then lower it also but if its in the stationary idle rpm/grams range then always leave about 10 deg higher spark in the main table then in the idle spark table so it gives room for the idle spark corrections to add spark if it has too, can also look at the adaptive coastdown spark table and take some spark out there in a constant value if it cant be done in the other tables cos its setup right for normal idle, staying constant will stop it from surging if its not needed to correct for something but just lower spark,
also i havnt played with them at all myself as i dont have them in my ecu but there are some baro/torque related tables to do with idle and they can help but have to be adjusted correctly could be worth looking that up on hptforum if the above dosnt get it right
bit to play with see how u go
if that dosnt do much the max fail thats at 200 u can lower that but that one is a overall hard stop so what i usually do is lower that one so i still get commanded winter cold start rpm and it will cap it from going above that, but if u go too low on that one it will limit the cold start TB opening, if u get the max fail and those percent max/brake all setup right the idle should be kept within those barriers and u then use the idle controls to control it within there, also the ''min rpm ref'' u have set to 750 just make that 600 so its lower then your commanded idle as that one its like a limit for idle corrections so if u go below it it wont correct the idle,
also see what your idle spark is at then in neutral and rolling see if its in the idle table or mains spark table or coastdown spark table and adjust the spark lower if its in the coastdown table can help, if its in the main spark table then lower it also but if its in the stationary idle rpm/grams range then always leave about 10 deg higher spark in the main table then in the idle spark table so it gives room for the idle spark corrections to add spark if it has too, can also look at the adaptive coastdown spark table and take some spark out there in a constant value if it cant be done in the other tables cos its setup right for normal idle, staying constant will stop it from surging if its not needed to correct for something but just lower spark,
also i havnt played with them at all myself as i dont have them in my ecu but there are some baro/torque related tables to do with idle and they can help but have to be adjusted correctly could be worth looking that up on hptforum if the above dosnt get it right
bit to play with see how u go
Thank you for such an informative response. The information you share is no doubt going to keep my mind occupied at its full potential, I'm still translating! (haha)ok yea it can be tricky as i dont think we have the direct tables found in the ecu to adjust it so have to find other ways, what u can try is the area scaler ''max percent'' lower that say .5% at a time see if it helps or if not then try the percent max brake, its one of those will allow that much more TB area from idle its like a hard limit, with the manual it can be tricky when ur in neutral but rolling it is different to clutch in rolling, the brake percent may be when ur clutch in and on the brakes stopped and the percent max when ur neutral and maby rolling u will just have to test,
if that dosnt do much the max fail thats at 200 u can lower that but that one is a overall hard stop so what i usually do is lower that one so i still get commanded winter cold start rpm and it will cap it from going above that, but if u go too low on that one it will limit the cold start TB opening, if u get the max fail and those percent max/brake all setup right the idle should be kept within those barriers and u then use the idle controls to control it within there, also the ''min rpm ref'' u have set to 750 just make that 600 so its lower then your commanded idle as that one its like a limit for idle corrections so if u go below it it wont correct the idle,
also see what your idle spark is at then in neutral and rolling see if its in the idle table or mains spark table or coastdown spark table and adjust the spark lower if its in the coastdown table can help, if its in the main spark table then lower it also but if its in the stationary idle rpm/grams range then always leave about 10 deg higher spark in the main table then in the idle spark table so it gives room for the idle spark corrections to add spark if it has too, can also look at the adaptive coastdown spark table and take some spark out there in a constant value if it cant be done in the other tables cos its setup right for normal idle, staying constant will stop it from surging if its not needed to correct for something but just lower spark,
also i havnt played with them at all myself as i dont have them in my ecu but there are some baro/torque related tables to do with idle and they can help but have to be adjusted correctly could be worth looking that up on hptforum if the above dosnt get it right
bit to play with see how u go
It's like the student that asks the professor a question, expecting to make an easy getaway, but instead spends the weekend with major homework, not the beach as planned...
Still got the 2/10s fuel pump pressure drop at consistently the same location. I went back into editor and checked the MAF calibration, there was a slight step in about five consecutive cells, not anything that appeared too noteworthy. If I recall the sputter occurs when I blast threw those cells aggressively? I interpolated that range of cells, so hoping the issue is solved. Just wondering your experience with slight steps in the MAF curve when quickly accelerating vs a more gradual acceleration threw areas that are slightly less than smooth?
Here is a screen shot of the fuel pressure dip, I have the channel values visible in this image, I think I am pretty dead-on with the dynamic?
My actual fuel is not lean in this screen shot, my wide band currently is reading a bit on the lean side as you can see, need to make some incremental adjustments. The O2s in closed loop are accurate reading a bit rich on the MAF
I wanted to share an observation.ok yea it can be tricky as i dont think we have the direct tables found in the ecu to adjust it so have to find other ways, what u can try is the area scaler ''max percent'' lower that say .5% at a time see if it helps or if not then try the percent max brake, its one of those will allow that much more TB area from idle its like a hard limit, with the manual it can be tricky when ur in neutral but rolling it is different to clutch in rolling, the brake percent may be when ur clutch in and on the brakes stopped and the percent max when ur neutral and maby rolling u will just have to test,
if that dosnt do much the max fail thats at 200 u can lower that but that one is a overall hard stop so what i usually do is lower that one so i still get commanded winter cold start rpm and it will cap it from going above that, but if u go too low on that one it will limit the cold start TB opening, if u get the max fail and those percent max/brake all setup right the idle should be kept within those barriers and u then use the idle controls to control it within there, also the ''min rpm ref'' u have set to 750 just make that 600 so its lower then your commanded idle as that one its like a limit for idle corrections so if u go below it it wont correct the idle,
also see what your idle spark is at then in neutral and rolling see if its in the idle table or mains spark table or coastdown spark table and adjust the spark lower if its in the coastdown table can help, if its in the main spark table then lower it also but if its in the stationary idle rpm/grams range then always leave about 10 deg higher spark in the main table then in the idle spark table so it gives room for the idle spark corrections to add spark if it has too, can also look at the adaptive coastdown spark table and take some spark out there in a constant value if it cant be done in the other tables cos its setup right for normal idle, staying constant will stop it from surging if its not needed to correct for something but just lower spark,
also i havnt played with them at all myself as i dont have them in my ecu but there are some baro/torque related tables to do with idle and they can help but have to be adjusted correctly could be worth looking that up on hptforum if the above dosnt get it right
bit to play with see how u go
I've been out logging and noticed if I coast to a stop out of gear I get the consistent higher 1200rpm revs, but if I depress the clutch pedal the revs drop to my set idle. If I come to a stop in gear the revs slowly lower, and once I come to a complete stop, the revs drop down to my set idle.
I have not made any of the changes you suggest yet at this point, just wanted to give you a bit more info if it's helpful.
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