midrange sputter after switching to E
04-12-2017, 10:49 PM
#1
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Thread Starter
midrange sputter after switching to E
Got my Ysi boosted vette tuned at JMS in San Antonio about 4 months ago after swapping to E-85 from a 93 tune and now the car all-the-sudden started to slightly shake and sputter (like a lean condition feeling) in the midrange RPM. We just got the ID2000s flowed and the inline fuel filter changed out from a cellophane to a stainless unit. Next we plan to drop the tanks and see how the fuel socks look on the Fore Innovations Triple pump setup. If they are anywhere near as dirty as the 88mm inline filter, they will be restrictive possible causing a lean condition. Car almost feels like the ECM lost the tune. Idle is good, WOT is terrible in the midrange but cleans up up top. Thoughts?
MODS:
ERL 427 Superdeck 6 bolt shortblock (M5)
TFS 255cc Gen-X heads
10 rib Ysi 2200X 2.75 pulley upper and 10 O/D IW lower
Full Fore fuel system (2000hp model) larger FAST rails
ID2000s
Speed density tuned by JMS in San Antonio
MODS:
ERL 427 Superdeck 6 bolt shortblock (M5)
TFS 255cc Gen-X heads
10 rib Ysi 2200X 2.75 pulley upper and 10 O/D IW lower
Full Fore fuel system (2000hp model) larger FAST rails
ID2000s
Speed density tuned by JMS in San Antonio
Last edited by bp92gsr; 04-12-2017 at 10:55 PM.
04-13-2017, 03:34 AM
#2
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St. Jude Donor '13-'14-'15
You can never lose your tune--even if the battery goes dead the base tune cannot change
The only thing that can change is the "learning" of your fuel trims--This normally takes about 50 miles of normal driving--the more your engine is modded the longer it takes to learn out
If you suspect a problem either rich or lean at throttle tip in or mid range this can be caused by several issues----The only way to find out exactly why is to have your car data logged---
E85 requires a lot more timing so data logging the actual timing can determine if it's a timing issue----as far as fuel is concerned Ethanol uses typically 30% more fuel---Data logging your AFR's with a wideband is the only way to see exactly what your actual AFR is
I run a 2014 C7 converted to E85 but the similarities are almost the same---At WOT I record 30* of timing with 70% ethanol---that is 6 more than all gas--At P/T you can see as much as 14* more timing
Did your tuner input all the correct P/T AFR values ? and the correct WOT fuel values?
At WOT the AFR should be commanded at approx .83 lamda---
If your car ran fine for awhile then went south this would indicate something else---Like after learning out the tune was so far off that it created your issues----
I would make sure you check your Ethanol % content---to make sure your E85 sensor is working----Someone with HP or EFILIVE can check those values-------Or install an Ethanol % gauge-----Start with checking this 1st
PS I dynoed my bolt on C7 on gas and then with 70% ethanol and I was pleased that it showed 25-30 more RWHP-------I love E85 !!!
The only thing that can change is the "learning" of your fuel trims--This normally takes about 50 miles of normal driving--the more your engine is modded the longer it takes to learn out
If you suspect a problem either rich or lean at throttle tip in or mid range this can be caused by several issues----The only way to find out exactly why is to have your car data logged---
E85 requires a lot more timing so data logging the actual timing can determine if it's a timing issue----as far as fuel is concerned Ethanol uses typically 30% more fuel---Data logging your AFR's with a wideband is the only way to see exactly what your actual AFR is
I run a 2014 C7 converted to E85 but the similarities are almost the same---At WOT I record 30* of timing with 70% ethanol---that is 6 more than all gas--At P/T you can see as much as 14* more timing
Did your tuner input all the correct P/T AFR values ? and the correct WOT fuel values?
At WOT the AFR should be commanded at approx .83 lamda---
If your car ran fine for awhile then went south this would indicate something else---Like after learning out the tune was so far off that it created your issues----
I would make sure you check your Ethanol % content---to make sure your E85 sensor is working----Someone with HP or EFILIVE can check those values-------Or install an Ethanol % gauge-----Start with checking this 1st
PS I dynoed my bolt on C7 on gas and then with 70% ethanol and I was pleased that it showed 25-30 more RWHP-------I love E85 !!!
04-13-2017, 08:45 AM
#3
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St. Jude Donor '15
Why not just measure fuel pressure and AFR and see what is actually going on before you start dropping tanks and doing unnecessary stuff?
Dropping tanks or throwing parts at it without more data isn't a very good way to move forward.
I can't believe I'm going to say this, but tblu is close to being right on this one
Dropping tanks or throwing parts at it without more data isn't a very good way to move forward.
I can't believe I'm going to say this, but tblu is close to being right on this one
Last edited by schpenxel; 04-13-2017 at 08:45 AM.
04-13-2017, 08:50 AM
#4
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Thread Starter
You can never lose your tune--even if the battery goes dead the base tune cannot change
The only thing that can change is the "learning" of your fuel trims--This normally takes about 50 miles of normal driving--the more your engine is modded the longer it takes to learn out
If you suspect a problem either rich or lean at throttle tip in or mid range this can be caused by several issues----The only way to find out exactly why is to have your car data logged---
E85 requires a lot more timing so data logging the actual timing can determine if it's a timing issue----as far as fuel is concerned Ethanol uses typically 30% more fuel---Data logging your AFR's with a wideband is the only way to see exactly what your actual AFR is
I run a 2014 C7 converted to E85 but the similarities are almost the same---At WOT I record 30* of timing with 70% ethanol---that is 6 more than all gas--At P/T you can see as much as 14* more timing
Did your tuner input all the correct P/T AFR values ? and the correct WOT fuel values?
At WOT the AFR should be commanded at approx .83 lamda---
If your car ran fine for awhile then went south this would indicate something else---Like after learning out the tune was so far off that it created your issues----
I would make sure you check your Ethanol % content---to make sure your E85 sensor is working----Someone with HP or EFILIVE can check those values-------Or install an Ethanol % gauge-----Start with checking this 1st
PS I dynoed my bolt on C7 on gas and then with 70% ethanol and I was pleased that it showed 25-30 more RWHP-------I love E85 !!!
The only thing that can change is the "learning" of your fuel trims--This normally takes about 50 miles of normal driving--the more your engine is modded the longer it takes to learn out
If you suspect a problem either rich or lean at throttle tip in or mid range this can be caused by several issues----The only way to find out exactly why is to have your car data logged---
E85 requires a lot more timing so data logging the actual timing can determine if it's a timing issue----as far as fuel is concerned Ethanol uses typically 30% more fuel---Data logging your AFR's with a wideband is the only way to see exactly what your actual AFR is
I run a 2014 C7 converted to E85 but the similarities are almost the same---At WOT I record 30* of timing with 70% ethanol---that is 6 more than all gas--At P/T you can see as much as 14* more timing
Did your tuner input all the correct P/T AFR values ? and the correct WOT fuel values?
At WOT the AFR should be commanded at approx .83 lamda---
If your car ran fine for awhile then went south this would indicate something else---Like after learning out the tune was so far off that it created your issues----
I would make sure you check your Ethanol % content---to make sure your E85 sensor is working----Someone with HP or EFILIVE can check those values-------Or install an Ethanol % gauge-----Start with checking this 1st
PS I dynoed my bolt on C7 on gas and then with 70% ethanol and I was pleased that it showed 25-30 more RWHP-------I love E85 !!!
Last edited by bp92gsr; 04-13-2017 at 08:53 AM.
04-13-2017, 09:00 AM
#5
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Thread Starter
And yes, I am very familiar with the burning properties of E-85. It burns 30% more, likes higher timing, runs cooler, and is approximately 105 octane. The entire fuel system in this car was designed to run E-85 and could also run E-100 with an additive. I plan to install a fuel pressure guage at the regulater soon; just havent gotten around to it.
04-13-2017, 09:02 AM
#6
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St. Jude Donor '15
It does sound plausible that something is going on due to E85 gunk breaking lose or clogging something up. Fuel pressure up near rails and some time with a wideband should figure it out pretty quick.
04-13-2017, 10:38 AM
#7
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Yeah, I have the Innovate ECB-1 gauge that monitors 4 channels (boost, fuel temp, AFR, and ethanol content %). I can also do some data logging with it but haven't figured out that part yet.
04-13-2017, 11:38 AM
#9
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04-13-2017, 06:09 PM
#11
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04-13-2017, 06:14 PM
#12
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04-14-2017, 08:13 AM
#13
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St. Jude Donor '15
He's new to the area if I recall. He's the one that figured out all the E85 stuff for these cars.
04-14-2017, 10:13 AM
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04-14-2017, 10:32 AM
#15
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St. Jude Donor '15
Which is pretty much the first thing you should have done 
Logging, that is.
Logging, that is.
Last edited by schpenxel; 04-14-2017 at 10:32 AM.
04-15-2017, 03:00 AM
#16
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St. Jude Donor '13-'14-'15
With Higher HP E85 engines you should also check your duty cycles of your injectors--The added 30% of fuel may run your DC above the industry standard of 80% Again the only way is to log your duty cycles----At WOT with to small of an injector they are pretty much open all the time anyway But at mid range or throttle tip in if your injectors are too small and maxed out this would create a leaness temporarily--- What injectors do you have ? and are they rated at 3 bar or 4 bar ???? Stock ??
04-15-2017, 11:27 AM
#17
Drifting
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St. Jude Donor '08
With Higher HP E85 engines you should also check your duty cycles of your injectors--The added 30% of fuel may run your DC above the industry standard of 80% Again the only way is to log your duty cycles----At WOT with to small of an injector they are pretty much open all the time anyway But at mid range or throttle tip in if your injectors are too small and maxed out this would create a leaness temporarily--- What injectors do you have ? and are they rated at 3 bar or 4 bar ???? Stock ??
04-17-2017, 09:58 AM
#18
Drifting
If you think the problem is fuel socks in the tanks, try this before pulling the tanks. Remove the fuel cap. Disconnect the fuel line at the fire wall connection. Send a low pressure blast of compressed air down the tube toward the tank.
It will clean the sock if it's dirty. put it back together and run it. It won't run very long before the sock is plugged again. But it should run good for a little while if the sock is dirty. If running good for a while and then reverting back to sputtering, then pull the tanks. If it never runs good after the air blast, its most likely not the tanks socks.
It will clean the sock if it's dirty. put it back together and run it. It won't run very long before the sock is plugged again. But it should run good for a little while if the sock is dirty. If running good for a while and then reverting back to sputtering, then pull the tanks. If it never runs good after the air blast, its most likely not the tanks socks.
04-22-2017, 12:19 AM
#19
Burning Brakes
You can never lose your tune--even if the battery goes dead the base tune cannot change
The only thing that can change is the "learning" of your fuel trims--This normally takes about 50 miles of normal driving--the more your engine is modded the longer it takes to learn out
If you suspect a problem either rich or lean at throttle tip in or mid range this can be caused by several issues----The only way to find out exactly why is to have your car data logged---
E85 requires a lot more timing so data logging the actual timing can determine if it's a timing issue----as far as fuel is concerned Ethanol uses typically 30% more fuel---Data logging your AFR's with a wideband is the only way to see exactly what your actual AFR is
I run a 2014 C7 converted to E85 but the similarities are almost the same---At WOT I record 30* of timing with 70% ethanol---that is 6 more than all gas--At P/T you can see as much as 14* more timing
Did your tuner input all the correct P/T AFR values ? and the correct WOT fuel values?
At WOT the AFR should be commanded at approx .83 lamda---
If your car ran fine for awhile then went south this would indicate something else---Like after learning out the tune was so far off that it created your issues----
I would make sure you check your Ethanol % content---to make sure your E85 sensor is working----Someone with HP or EFILIVE can check those values-------Or install an Ethanol % gauge-----Start with checking this 1st
PS I dynoed my bolt on C7 on gas and then with 70% ethanol and I was pleased that it showed 25-30 more RWHP-------I love E85 !!!
The only thing that can change is the "learning" of your fuel trims--This normally takes about 50 miles of normal driving--the more your engine is modded the longer it takes to learn out
If you suspect a problem either rich or lean at throttle tip in or mid range this can be caused by several issues----The only way to find out exactly why is to have your car data logged---
E85 requires a lot more timing so data logging the actual timing can determine if it's a timing issue----as far as fuel is concerned Ethanol uses typically 30% more fuel---Data logging your AFR's with a wideband is the only way to see exactly what your actual AFR is
I run a 2014 C7 converted to E85 but the similarities are almost the same---At WOT I record 30* of timing with 70% ethanol---that is 6 more than all gas--At P/T you can see as much as 14* more timing
Did your tuner input all the correct P/T AFR values ? and the correct WOT fuel values?
At WOT the AFR should be commanded at approx .83 lamda---
If your car ran fine for awhile then went south this would indicate something else---Like after learning out the tune was so far off that it created your issues----
I would make sure you check your Ethanol % content---to make sure your E85 sensor is working----Someone with HP or EFILIVE can check those values-------Or install an Ethanol % gauge-----Start with checking this 1st
PS I dynoed my bolt on C7 on gas and then with 70% ethanol and I was pleased that it showed 25-30 more RWHP-------I love E85 !!!