Siemens 80's Fat At Idle and Cruise
06-28-2017, 05:01 PM
#1
Siemens 80's Fat At Idle and Cruise I've got an issue that doesn't seem to be making any sense so I'm hoping someone here can shed some light on it.
I'm currently running Siemens 80 lb. injectors in my 4th turbo F-Body with a stock fuel system and twin 255's in the bucket, one on a Hobbs switch.
My tuner (who is a reputable tuner) has been unable to lean out my idle and believes my AFR gauge is reading inaccurate.
At idle my AFR reads 12.0 and 12.6 w/ the AC on consistently.
When cruising down the road under zero load and little to no throttle again reading 12.0 if coasting down a small hill then 11.0 AFR.
However if I apply just the slightest amount of throttle my AFR comes up to 13.7 or if I encounter a slight grade at little to no throttle again it leans out to 13.7 or higher.
It also seems like as soon as the throttle blades crack the AFR comes right up to where it should be.
I recently had the injectors cleaned because they were clogged, I also re-calibrated my O2 sensor on my AFR gauge to confirm its reading.
The car runs fantastic, throttle is clean and snappy and pulls hard maintaining a 11.5 AFR at WOT but just reads fat at idle and light throttle cruising.
Any insight or recommendations would be greatly appreciated.
Cheers.
I'm currently running Siemens 80 lb. injectors in my 4th turbo F-Body with a stock fuel system and twin 255's in the bucket, one on a Hobbs switch.
My tuner (who is a reputable tuner) has been unable to lean out my idle and believes my AFR gauge is reading inaccurate.
At idle my AFR reads 12.0 and 12.6 w/ the AC on consistently.
When cruising down the road under zero load and little to no throttle again reading 12.0 if coasting down a small hill then 11.0 AFR.
However if I apply just the slightest amount of throttle my AFR comes up to 13.7 or if I encounter a slight grade at little to no throttle again it leans out to 13.7 or higher.
It also seems like as soon as the throttle blades crack the AFR comes right up to where it should be.
I recently had the injectors cleaned because they were clogged, I also re-calibrated my O2 sensor on my AFR gauge to confirm its reading.
The car runs fantastic, throttle is clean and snappy and pulls hard maintaining a 11.5 AFR at WOT but just reads fat at idle and light throttle cruising.
Any insight or recommendations would be greatly appreciated.
Cheers.
06-28-2017, 10:41 PM
#6
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If tuner is using efilive, this is what happened to me, I'm also a reputable tuner lol
https://forum.efilive.com/showthread...um-pulse-width
https://forum.efilive.com/showthread...um-pulse-width
06-29-2017, 08:51 AM
#7
SVSlow- Yes sir, factory ECU.
SBCGenII / Slowride- I'm currently using EFI Live, I've got a data log that I can share?
LS1Freek- Thank you for the info, I'll be sure to share this with my tuner.
I'm trying to help my tuner out, poor guy is way over worked and if I can help find a solution for this I'm happy to do so.
Thank you guys!
SBCGenII / Slowride- I'm currently using EFI Live, I've got a data log that I can share?
LS1Freek- Thank you for the info, I'll be sure to share this with my tuner.
I'm trying to help my tuner out, poor guy is way over worked and if I can help find a solution for this I'm happy to do so.
Thank you guys!
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06-29-2017, 09:53 AM
#8
FormerVendor
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Afr uego calibration Hi SS, I too like the DEKA (?) 80's with min PW of .813ms for repeatable operation.
What is your PW when the problem is reported ?
My guess is the false report of the UEGO.
What is the Manufacturer ?
What is the Spark Plug color ?
What is the Fuel Pressure ?
Lance
What is your PW when the problem is reported ?
My guess is the false report of the UEGO.
What is the Manufacturer ?
What is the Spark Plug color ?
What is the Fuel Pressure ?
Lance
06-29-2017, 10:41 AM
#9
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SVSlow- Yes sir, factory ECU.
SBCGenII / Slowride- I'm currently using EFI Live, I've got a data log that I can share?
LS1Freek- Thank you for the info, I'll be sure to share this with my tuner.
I'm trying to help my tuner out, poor guy is way over worked and if I can help find a solution for this I'm happy to do so.
Thank you guys!
SBCGenII / Slowride- I'm currently using EFI Live, I've got a data log that I can share?
LS1Freek- Thank you for the info, I'll be sure to share this with my tuner.
I'm trying to help my tuner out, poor guy is way over worked and if I can help find a solution for this I'm happy to do so.
Thank you guys!
06-29-2017, 04:52 PM
#11
What is your PW when the problem is reported? What is PW?
My guess is the false report of the UEGO. I don't believe the UEGO is false sicnce the reading changes.
What is the Manufacturer? Its an Innovate MTX.
What is the Spark Plug color ? Haven't checked it but it smells rich.
What is the Fuel Pressure ? What ever stock is since I'm using the factory system.
06-29-2017, 04:59 PM
#13
Also If your tuner doesn't want to mess with the cax file stuff, I'll change your minimum transient pulse in the tune for you. (It's a table hidden in efilive without the use of the cax file). Just email the tune file to ls1freek@gmail.com
I'm gonna give him a few days to respond since I sent him that link to EFI Live you posted but if he doesn't respond soon I'll shoot you my scan.
I really appreciate you offering to take a look as well, thank you!
06-29-2017, 05:11 PM
#14
If tuner is using efilive, this is what happened to me, I'm also a reputable tuner lol
https://forum.efilive.com/showthread...um-pulse-width
https://forum.efilive.com/showthread...um-pulse-width
not to hijack but i read this thread and im having a very similar issue with the same injectors. i run hptuners so i dont know the efilive table codes. can you rundown what tables you changed to what?
thanks
06-29-2017, 06:03 PM
#16
Its a 2002 Camaro SS, it was fine with the old Siemens 60's on lower boost which really chaps my ***, should've left the ****** thing alone lol.
I remember my tuner saying he leaned the VE table way out and it didn't make a difference so he thought maybe the injectors couldn't pulse low enough to lean out.
He leaned it out to the point the car would stall when I hit the gas but still 12.0 at idle.
I may have been inclined to believe that except a friend of mine has the same injectors in his 5.7 and it idles at 14.7 AFR.
06-29-2017, 06:08 PM
#17
Yes sir, just the single 255 at idle.
Its a 2002 Camaro SS, it was fine with the old Siemens 60's on lower boost which really chaps my ***, should've left the ****** thing alone lol.
I remember my tuner saying he leaned the VE table way out and it didn't make a difference so he thought maybe the injectors couldn't pulse low enough to lean out.
He leaned it out to the point the car would stall when I hit the gas but still 12.0 at idle.
I may have been inclined to believe that except a friend of mine has the same injectors in his 5.7 and it idles at 14.7 AFR.
Its a 2002 Camaro SS, it was fine with the old Siemens 60's on lower boost which really chaps my ***, should've left the ****** thing alone lol.
I remember my tuner saying he leaned the VE table way out and it didn't make a difference so he thought maybe the injectors couldn't pulse low enough to lean out.
He leaned it out to the point the car would stall when I hit the gas but still 12.0 at idle.
I may have been inclined to believe that except a friend of mine has the same injectors in his 5.7 and it idles at 14.7 AFR.
06-29-2017, 11:37 PM
#19
Had the same issue when I put my 80's in when stock fuel system and got it under control with adjusting min fuel pulses. Even ran them on my car NA for a while before the boost. Tables aren't adjusted right. You running SD tune or trying a MAF? Have seen this with a MAF when there is overlap of load on cars, best just to go SD but takes time to tune.
My suggestion, start learning to tune, Fbody is about as easy as it gets to start out.
My suggestion, start learning to tune, Fbody is about as easy as it gets to start out.
06-30-2017, 09:17 AM
#20
Hi guys, I've attached the tune and scan from the drive.
The tune being the VCLS1B_12 and the scan is LS1B_0076.
Tune 12 runs the best thus far, subsequent tunes after this one run steadily worse with a lean bog when the throttle opens that gets steadily worse showing the progression of leaning out the VE table I guess.
My driving factor here is I need the car running for the end of July so I can drive it to meet my family on vacation so I'm trying to sort this out lol.
Thanks again everyone for your help!
I'm all over it Rawr, I'm currently looking at laptops and am saving up my pennies so when an HP Tuners setup becomes available on here I can jump on it.
All this waiting and wasted time has motivated me to learn to do this myself for sure.
The tune being the VCLS1B_12 and the scan is LS1B_0076.
Tune 12 runs the best thus far, subsequent tunes after this one run steadily worse with a lean bog when the throttle opens that gets steadily worse showing the progression of leaning out the VE table I guess.
My driving factor here is I need the car running for the end of July so I can drive it to meet my family on vacation so I'm trying to sort this out lol.
Thanks again everyone for your help!
I'm all over it Rawr, I'm currently looking at laptops and am saving up my pennies so when an HP Tuners setup becomes available on here I can jump on it.
All this waiting and wasted time has motivated me to learn to do this myself for sure.