Negative Mid LTFT and more issues!
Jan 11, 2017, 04:53 PM
#1
Negative Mid LTFT and more issues!
Hello EvoM,
I'm not very experienced with tuning. I would say I understand some of the simple concepts but recently I swapped cams from GSC S3's back to stock because the car was not driving very well when cruising around 2000 rpms and it would die while coming to stop with the AC on. I was sure that the cams were the issue. I was tuned by a prominent, local, tuner and I had him send me, remotely, a new tune for the stock cams. However, the car is running very poorly and my tuner is very difficult to get a hold of. Additionally, I would like to be able to troubleshoot issues on my own.
My current issues are that my mid LTFT is at -12.5% (maxed from my understanding). I go pig-rich when boost is built and the car actually knocks (CEL flashes). Finally, when the car is first started (in other words, motor is cold) if I tap the gas (as in I clutch in, give it gas to start to move) the car goes so rich it actually kills the car. If I am able to save it by getting out of the gas, the car nearly stalls and just chugs (because it's so rich).
I am using EvoScan and ECUFlash. I also have an AEM UEGO wideband installed that I am able to log. I am going to attach a log of me idling last night. I really need help as the car is almost undriveable. I HAVE done several boost leak tests and I resolved the couple of very minor leaks that I found.
That being said, here are the current relevant modifications to my car:
Intake:
3" hard intake pipe with Amsoil conical filter (BOV re-routed along with PCV line from the valve cover connected)
ETS 3" FMIC w/ short route piping
BR Ported TB and IM
Exhaust:
Megan racing o2 housing
Unknown 3" DP (ceramic coated)
ETS Hi-flo cat
Apexi' cat-back exhaust
Fuel:
Stock injectors
Walbro 255
Tune:
Speed density with Grimmspeed 3-port boost control and Omni 4-bar MAP.
Something else that MAY be important is that this car was built by the previous owner, it had a top mounted 6266, EvoDan double pumper fuel setup, and huge injectors. When I got the car it was in pieces. He gave me a stock fuel pump assembly with, what I believe, is a stock pump along with a set of stock injectors. I installed both and I also had to create and install my own "Pepboys special" high pressure fuel feed lines (they are just generic fuel lines). Besides that, the rest of the fuel system is (or should be) stock.
Thank you everyone for your help!
I'm not very experienced with tuning. I would say I understand some of the simple concepts but recently I swapped cams from GSC S3's back to stock because the car was not driving very well when cruising around 2000 rpms and it would die while coming to stop with the AC on. I was sure that the cams were the issue. I was tuned by a prominent, local, tuner and I had him send me, remotely, a new tune for the stock cams. However, the car is running very poorly and my tuner is very difficult to get a hold of. Additionally, I would like to be able to troubleshoot issues on my own.
My current issues are that my mid LTFT is at -12.5% (maxed from my understanding). I go pig-rich when boost is built and the car actually knocks (CEL flashes). Finally, when the car is first started (in other words, motor is cold) if I tap the gas (as in I clutch in, give it gas to start to move) the car goes so rich it actually kills the car. If I am able to save it by getting out of the gas, the car nearly stalls and just chugs (because it's so rich).
I am using EvoScan and ECUFlash. I also have an AEM UEGO wideband installed that I am able to log. I am going to attach a log of me idling last night. I really need help as the car is almost undriveable. I HAVE done several boost leak tests and I resolved the couple of very minor leaks that I found.
That being said, here are the current relevant modifications to my car:
Intake:
3" hard intake pipe with Amsoil conical filter (BOV re-routed along with PCV line from the valve cover connected)
ETS 3" FMIC w/ short route piping
BR Ported TB and IM
Exhaust:
Megan racing o2 housing
Unknown 3" DP (ceramic coated)
ETS Hi-flo cat
Apexi' cat-back exhaust
Fuel:
Stock injectors
Walbro 255
Tune:
Speed density with Grimmspeed 3-port boost control and Omni 4-bar MAP.
Something else that MAY be important is that this car was built by the previous owner, it had a top mounted 6266, EvoDan double pumper fuel setup, and huge injectors. When I got the car it was in pieces. He gave me a stock fuel pump assembly with, what I believe, is a stock pump along with a set of stock injectors. I installed both and I also had to create and install my own "Pepboys special" high pressure fuel feed lines (they are just generic fuel lines). Besides that, the rest of the fuel system is (or should be) stock.
Thank you everyone for your help!
Last edited by RelentlessEVO; Feb 1, 2017 at 05:36 PM.
Jan 12, 2017, 03:29 AM
#2
We need clarification.
The way I read it now, you have larger fuel feed line, stock pump, stock injectors. What fuel Rail? Stock or aftermarket FPR?
Was it tuned as in the last thing you did after replacing or returning to stock, or when was it tuned?
Your GSC 3's could have been tuned way better, and to run way better.
Knocking in fuel could be because it is so rich, but very unlikely. Could be an internal issue, also could be the stock profile on the cam and timing tuning within the rom for the other cams.
Have someone take a look at your rom, and give us the version you are running? Is it a 9417 variant, 9653 variant, or what?
You can post your ROM just like your log. If anyone hims and hahs because it is a vendor tuned rom, then pick someone privately and offer to send it to them so they can take a discrete look at it.
I looked at your log, and there is not enough in the log to make any thoughts. Need more data fields to understand.
Get back to us, someone will help get you sorted out.
The way I read it now, you have larger fuel feed line, stock pump, stock injectors. What fuel Rail? Stock or aftermarket FPR?
Was it tuned as in the last thing you did after replacing or returning to stock, or when was it tuned?
Your GSC 3's could have been tuned way better, and to run way better.
Knocking in fuel could be because it is so rich, but very unlikely. Could be an internal issue, also could be the stock profile on the cam and timing tuning within the rom for the other cams.
Have someone take a look at your rom, and give us the version you are running? Is it a 9417 variant, 9653 variant, or what?
You can post your ROM just like your log. If anyone hims and hahs because it is a vendor tuned rom, then pick someone privately and offer to send it to them so they can take a discrete look at it.
I looked at your log, and there is not enough in the log to make any thoughts. Need more data fields to understand.
Get back to us, someone will help get you sorted out.
Jan 13, 2017, 10:35 AM
#3
EvoM Community Team Leader
Changing cams will change the Volumetric efficiency of the engine and have a much larger effect on the overall tune for an SD setup vs a MAF. You probably need a more substantial retune to get it dialed back in.
On a different note, you said you did a boost leak test (good), but what else did you eliminate as a possible cause of your original problems before swapping the cams, and what is the maintenance history like?
On a different note, you said you did a boost leak test (good), but what else did you eliminate as a possible cause of your original problems before swapping the cams, and what is the maintenance history like?
Jan 13, 2017, 01:53 PM
#4
First, thank you for responding Raceghost. My answers to your questions are below and in bold.
Thank you again for responding!
We need clarification.
The way I read it now, you have larger fuel feed line, stock pump, stock injectors. What fuel Rail? Stock or aftermarket FPR?
To clarify my fuel setup: I have stock injectors, stock pump, stock FPR, and I have some generic rubber fuel line hose from the fuel pump assembly to the first hardline (where MR556881 should go) and then more generic fuel line hose from the hardline to the next hardline (where MR556882 should go). I should state that I have had some leaking from the fuel lines there. I replaced the hose clamps I had on there to more robust worm clamps but the other day after the car sat for 3 or 4 days it pissed a lot of fuel out onto the ground below the fuel tank. I have ordered both OEM high pressure fuel feed lines and will be installing them in the next week to rule them out as a contributing factor.
Was it tuned as in the last thing you did after replacing or returning to stock, or when was it tuned?
So, I was tuned previously, with the GSC S3 cams. I then swapped them out for the stock cams and paid for a remote re-tune. My tuner worked with me and sent me a new tune and I sent him back logs and then he would tweak the tune. I have a couple of issues that make it difficult for me to log and load new tunes. I use a small Odyssey battery which has no problem starting the car but does not provide enough juice to allow me to upload a new rom. So I literally have to have jumper cables running to another running car and that is a pain in the *** in my current living / parking situation. On top of that, recently, my logger cable started to not connect to my laptop and anytime my laptop would move it would disconnect.
Your GSC 3's could have been tuned way better, and to run way better.
That would be pretty frustrating if it was some underlying fueling issue even with the last tune. I thought I had mentioned these issues to my tuner and the response was that it was because of the cams. Regardless, if it is some kind of mechanical issue it wouldn't be the fault of my tuner, I don't think.
Knocking in fuel could be because it is so rich, but very unlikely. Could be an internal issue, also could be the stock profile on the cam and timing tuning within the rom for the other cams.
As mentioned above I am running a new tune for the stock cams so I'm really hoping the knock is just from running amazingly rich.
Have someone take a look at your rom, and give us the version you are running? Is it a 9417 variant, 9653 variant, or what?
I have reached out to my tuner and explained my problems but again, he is very busy and very difficult to get a hold of. I just checked and I am running ROM 88591715 with speed density, using the fuel temp sensor (using the fuel temp sensor instead of an IAT is a whole other ball of wax that concerns me but I understand that it is acceptable most of the time).
You can post your ROM just like your log. If anyone hims and hahs because it is a vendor tuned rom, then pick someone privately and offer to send it to them so they can take a discrete look at it.
This is EXACTLY why I didn't upload it. I'm not trying to put anyone on blast or point any fingers. This may be a mechanical / fueling issue that cannot be resolved by tune. I am not saying it is my tuners fault that I'm having these issues. I am simply reaching out the collective that is EvoM to get some opinions on what can cause my symptoms. If anyone reading this, that is experienced in tuning, would be willing to take a look at my rom please PM me.
I looked at your log, and there is not enough in the log to make any thoughts. Need more data fields to understand.
What other inputs would you like to see?
Get back to us, someone will help get you sorted out.
The way I read it now, you have larger fuel feed line, stock pump, stock injectors. What fuel Rail? Stock or aftermarket FPR?
To clarify my fuel setup: I have stock injectors, stock pump, stock FPR, and I have some generic rubber fuel line hose from the fuel pump assembly to the first hardline (where MR556881 should go) and then more generic fuel line hose from the hardline to the next hardline (where MR556882 should go). I should state that I have had some leaking from the fuel lines there. I replaced the hose clamps I had on there to more robust worm clamps but the other day after the car sat for 3 or 4 days it pissed a lot of fuel out onto the ground below the fuel tank. I have ordered both OEM high pressure fuel feed lines and will be installing them in the next week to rule them out as a contributing factor.
Was it tuned as in the last thing you did after replacing or returning to stock, or when was it tuned?
So, I was tuned previously, with the GSC S3 cams. I then swapped them out for the stock cams and paid for a remote re-tune. My tuner worked with me and sent me a new tune and I sent him back logs and then he would tweak the tune. I have a couple of issues that make it difficult for me to log and load new tunes. I use a small Odyssey battery which has no problem starting the car but does not provide enough juice to allow me to upload a new rom. So I literally have to have jumper cables running to another running car and that is a pain in the *** in my current living / parking situation. On top of that, recently, my logger cable started to not connect to my laptop and anytime my laptop would move it would disconnect.
Your GSC 3's could have been tuned way better, and to run way better.
That would be pretty frustrating if it was some underlying fueling issue even with the last tune. I thought I had mentioned these issues to my tuner and the response was that it was because of the cams. Regardless, if it is some kind of mechanical issue it wouldn't be the fault of my tuner, I don't think.
Knocking in fuel could be because it is so rich, but very unlikely. Could be an internal issue, also could be the stock profile on the cam and timing tuning within the rom for the other cams.
As mentioned above I am running a new tune for the stock cams so I'm really hoping the knock is just from running amazingly rich.
Have someone take a look at your rom, and give us the version you are running? Is it a 9417 variant, 9653 variant, or what?
I have reached out to my tuner and explained my problems but again, he is very busy and very difficult to get a hold of. I just checked and I am running ROM 88591715 with speed density, using the fuel temp sensor (using the fuel temp sensor instead of an IAT is a whole other ball of wax that concerns me but I understand that it is acceptable most of the time).
You can post your ROM just like your log. If anyone hims and hahs because it is a vendor tuned rom, then pick someone privately and offer to send it to them so they can take a discrete look at it.
This is EXACTLY why I didn't upload it. I'm not trying to put anyone on blast or point any fingers. This may be a mechanical / fueling issue that cannot be resolved by tune. I am not saying it is my tuners fault that I'm having these issues. I am simply reaching out the collective that is EvoM to get some opinions on what can cause my symptoms. If anyone reading this, that is experienced in tuning, would be willing to take a look at my rom please PM me.
I looked at your log, and there is not enough in the log to make any thoughts. Need more data fields to understand.
What other inputs would you like to see?
Get back to us, someone will help get you sorted out.
Jan 13, 2017, 02:04 PM
#5
Thank you for responding Biggiesacks. Please see my responses to your questions below in bold.
Changing cams will change the Volumetric efficiency of the engine and have a much larger effect on the overall tune for an SD setup vs a MAF. You probably need a more substantial retune to get it dialed back in.
I have a new tune for the stock cams from my tuner and it is still exhibiting the symptoms I described above.
On a different note, you said you did a boost leak test (good), but what else did you eliminate as a possible cause of your original problems before swapping the cams, and what is the maintenance history like?
So before swapping the cams out I just assumed they were the problem. I read on various sources that it is common for Evo's to die in vacuum while coming to a stop with aggressive cams (and the S3's are pretty damn aggressive). The car did use to hesitate and stutter under cold starts but again, due to lack of understanding I guess, I assumed that it was a byproduct of aggressive cams. I guess it was wishful thinking that swapping to the stock cams would resolve those problems.
The maintenance history, I think, looks good. Well, during my ownership at least. I've put roughly 5,000 miles on the car in the last year, but it's only been running since May of 2016. In that time I've replaced a torn axle boot, changed the oil once, replaced the trans, transfercase, and rear diff fluids, timing belt and balance shaft belt with all new pulleys and tensioners, all new exhaust gaskets, valve cover gasket, cam seals, etc. I've spent, literally, thousands of dollars on OEM parts, gaskets, seals, etc. over the last year trying to make this car as close to new and reliable as I can.
I have a new tune for the stock cams from my tuner and it is still exhibiting the symptoms I described above.
On a different note, you said you did a boost leak test (good), but what else did you eliminate as a possible cause of your original problems before swapping the cams, and what is the maintenance history like?
So before swapping the cams out I just assumed they were the problem. I read on various sources that it is common for Evo's to die in vacuum while coming to a stop with aggressive cams (and the S3's are pretty damn aggressive). The car did use to hesitate and stutter under cold starts but again, due to lack of understanding I guess, I assumed that it was a byproduct of aggressive cams. I guess it was wishful thinking that swapping to the stock cams would resolve those problems.
The maintenance history, I think, looks good. Well, during my ownership at least. I've put roughly 5,000 miles on the car in the last year, but it's only been running since May of 2016. In that time I've replaced a torn axle boot, changed the oil once, replaced the trans, transfercase, and rear diff fluids, timing belt and balance shaft belt with all new pulleys and tensioners, all new exhaust gaskets, valve cover gasket, cam seals, etc. I've spent, literally, thousands of dollars on OEM parts, gaskets, seals, etc. over the last year trying to make this car as close to new and reliable as I can.
Jan 13, 2017, 02:52 PM
#6
EvoM Community Team Leader
So this issue didn't come up during the tuning session(s)?
Jan 13, 2017, 02:59 PM
#7
No, the bogging / stuttering / dying when giving it gas while the motor is cold never came up because he only drove and tuned it when the motor was warm.
The other issue of the car dying when coming to stop with the A/C is on did not come up because my A/C wasn't working when I had the original tune.
The other issue of the car dying when coming to stop with the A/C is on did not come up because my A/C wasn't working when I had the original tune.
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Jan 13, 2017, 03:08 PM
#8
EvoM Community Team Leader
If it was me, I would re-install the cams, revert back to the original pre-swap tune, and work on fixing what ever issues you have after reverting back. Your issues sound like they are probably tune related. Going pig rich under boost and knocking sound like things the tuner should have addressed. The fuel trims being what they are is certainly a red flag. Im not as familiar with SD but that would denote a problem with injector scaling or some other calibration.
Good suggestion.
Jan 15, 2017, 04:02 AM
#11
You haven't checked fuel pressure?
So your cams issue about dying when rolling to a stop, is definitely tunable. There are a few tables to adjust on that situation in the idle, timing, and fuel.
I am not that familiar with SD, as I find MAF is more adjustable when it comes to elements like elevation and temperature.
I wasn't suggesting putting your tuner on blast, it was more following the rules of the forum and not posting vendor specific ROMS.
Self tuned is another situation.
Our cars are high dollar hookers. You look at her and it will cost you. LOL.
Sounds like you did some good maintenance and are relatively wanting to run close to stock.
Fix your fuel issue, and dial in the injectors, they are not that hard... well, if you have battery troubles, you might run into an issue trying to load/log tunes out their on the road.
Buy yourself a good battery charger you can run via extension cord for when your sitting at idle at your pad.
Keep us informed.
Jan 15, 2017, 01:13 PM
#12
Account Disabled
A leak doesn't change the pressure, it's loss of volume.
The pressure will be too high as it always IS with mods to the fuel system.
The pressure will be too high as it always IS with mods to the fuel system.
Last edited by RightSaid fred; Jan 15, 2017 at 06:30 PM.
Jan 17, 2017, 12:35 PM
#13
He said he was leaking fuel, so pressure is definitely down there bub.
So your cams issue about dying when rolling to a stop, is definitely tunable. There are a few tables to adjust on that situation in the idle, timing, and fuel.
I am not that familiar with SD, as I find MAF is more adjustable when it comes to elements like elevation and temperature.
I wasn't suggesting putting your tuner on blast, it was more following the rules of the forum and not posting vendor specific ROMS.
Self tuned is another situation.
Our cars are high dollar hookers. You look at her and it will cost you. LOL.
Sounds like you did some good maintenance and are relatively wanting to run close to stock.
Fix your fuel issue, and dial in the injectors, they are not that hard... well, if you have battery troubles, you might run into an issue trying to load/log tunes out their on the road.
Buy yourself a good battery charger you can run via extension cord for when your sitting at idle at your pad.
Keep us informed.
So your cams issue about dying when rolling to a stop, is definitely tunable. There are a few tables to adjust on that situation in the idle, timing, and fuel.
I am not that familiar with SD, as I find MAF is more adjustable when it comes to elements like elevation and temperature.
I wasn't suggesting putting your tuner on blast, it was more following the rules of the forum and not posting vendor specific ROMS.
Self tuned is another situation.
Our cars are high dollar hookers. You look at her and it will cost you. LOL.
Sounds like you did some good maintenance and are relatively wanting to run close to stock.
Fix your fuel issue, and dial in the injectors, they are not that hard... well, if you have battery troubles, you might run into an issue trying to load/log tunes out their on the road.
Buy yourself a good battery charger you can run via extension cord for when your sitting at idle at your pad.
Keep us informed.
I do have a theory. I noticed that I don't have the FPR solenoid as it appears the prior-owner removed it. I know it's common to do but could that cause this issue?
I also uploaded the most recent tune that was sent to me by my tuner and went for a quick drive. After the car was warmed up I rolled into boost and the car went dead rich again. It didn't stutter like it has in the past but then again I had just reset the ECU so that may be why. I'm wondering if I will need to purchase an AFPR and then have the car re-tuned. I would think that this is something that could be tuned out by my tuner in the meantime though?
I appreciate all the comments and suggestions! Keep 'em coming!
Jan 17, 2017, 12:36 PM
#14
If it was me, I would re-install the cams, revert back to the original pre-swap tune, and work on fixing what ever issues you have after reverting back. Your issues sound like they are probably tune related. Going pig rich under boost and knocking sound like things the tuner should have addressed. The fuel trims being what they are is certainly a red flag. Im not as familiar with SD but that would denote a problem with injector scaling or some other calibration.
Jan 17, 2017, 08:06 PM
#15
Account Disabled
The solenoid is to increase the pressure with a hot start.
You need a pressure gauge so you can measure the pressure and then fix it.
