Lean AFR issue
10-31-2017, 06:04 PM
#1
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Lean AFR issue
My car has been running perfect but now is running consisstantly lean under boost. It will start leaner than normal and end leaner at 13.5 AFR where normal was always around 10.6 AFR at full tilt. Fuel pressure is as usual,75- 80psi. Car runs perfect other than that but can not keep my foot into it do to this issue. I have no logging but do have real time for all outputs, fuel,afr,timing and such. Throttle angle is full open,watching it, and shows '77" on Aeroforce gauge.
What do you guys think?
update:
Well this is great. After checking the throttle body I then had no start up "communication" on my OBD Aeroforce gauge. So I hooked up my DAS and that will not communicate at all. Green light is on for power but can not read anything. I can go in with a snap on scanner but that's it.
Also tried to reload my tune and ended up blanking the ECU so loaded the stock tune in. Are tunes a one shot deal when sent to us so they can not be put in other cars as well ?
What do you guys think?
update:
Well this is great. After checking the throttle body I then had no start up "communication" on my OBD Aeroforce gauge. So I hooked up my DAS and that will not communicate at all. Green light is on for power but can not read anything. I can go in with a snap on scanner but that's it.
Also tried to reload my tune and ended up blanking the ECU so loaded the stock tune in. Are tunes a one shot deal when sent to us so they can not be put in other cars as well ?
Last edited by SICAMG; 11-01-2017 at 10:30 AM.
11-01-2017, 11:42 AM
#2
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Eurocharged Performance ML63 and TT lambo
sounds like leak of somesort or bad o2 sensor
Tunes can be applied as many times as you want to the same car. You have other things going on
I would check fuses
Tunes can be applied as many times as you want to the same car. You have other things going on
I would check fuses
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loungn14 (11-01-2017)
11-01-2017, 01:06 PM
#4
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Going to recalibrate the o2 and test drive home from work. I still do not understand why the das or obd gauge will not link, but the snap-on scanner does.
so Loungn.....I can down load the same tune multiple times if it was needed? I thought maybe it was a one shot deal so you couldn't go around tuning other car
I will try and load it in again tonight and see if it links up.
so Loungn.....I can down load the same tune multiple times if it was needed? I thought maybe it was a one shot deal so you couldn't go around tuning other car
I will try and load it in again tonight and see if it links up.
11-01-2017, 01:10 PM
#5
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Eurocharged Performance ML63 and TT lambo
Going to recalibrate the o2 and test drive home from work. I still do not understand why the das or obd gauge will not link, but the snap-on scanner does.
so Loungn.....I can down load the same tune multiple times if it was needed? I thought maybe it was a one shot deal so you couldn't go around tuning other car
I will try and load it in again tonight and see if it links up.
so Loungn.....I can down load the same tune multiple times if it was needed? I thought maybe it was a one shot deal so you couldn't go around tuning other car
I will try and load it in again tonight and see if it links up.
Sounds like a sam problem or fus
11-01-2017, 08:41 PM
#6
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So I recalibrated the wide band,down loaded a new file sent by Tony and was able to get in with DAS.
I did all this after disconnecting the battery for a while. Was very low on voltage because forgot to also mention the alternator fried the diodes so had to replace that. I guess some funny things happened with the lower voltage. I also got a tune with a little more fuel to compensate for the colder temps as per Tony at Race IQ. I think you are right about the leaner AFR's Craig, Temps are 30 degrees colder since I last tested so should be a big change in the AFR and that"s what I am seeing...{I hope} Thanks for the input Loungn, Craig, and Tony at Race IQ and I will update on the results on Thursday's blast to work. Trying to get this all sorted before I throw a new rear diff in wit steeper gears this weekend.
I did all this after disconnecting the battery for a while. Was very low on voltage because forgot to also mention the alternator fried the diodes so had to replace that. I guess some funny things happened with the lower voltage. I also got a tune with a little more fuel to compensate for the colder temps as per Tony at Race IQ. I think you are right about the leaner AFR's Craig, Temps are 30 degrees colder since I last tested so should be a big change in the AFR and that"s what I am seeing...{I hope} Thanks for the input Loungn, Craig, and Tony at Race IQ and I will update on the results on Thursday's blast to work. Trying to get this all sorted before I throw a new rear diff in wit steeper gears this weekend.
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11-02-2017, 08:08 AM
#8
Senior Member
11-02-2017, 07:05 PM
#9
So I recalibrated the wide band,down loaded a new file sent by Tony and was able to get in with DAS.
I did all this after disconnecting the battery for a while. Was very low on voltage because forgot to also mention the alternator fried the diodes so had to replace that. I guess some funny things happened with the lower voltage. I also got a tune with a little more fuel to compensate for the colder temps as per Tony at Race IQ. I think you are right about the leaner AFR's Craig, Temps are 30 degrees colder since I last tested so should be a big change in the AFR and that"s what I am seeing...{I hope} Thanks for the input Loungn, Craig, and Tony at Race IQ and I will update on the results on Thursday's blast to work. Trying to get this all sorted before I throw a new rear diff in wit steeper gears this weekend.
I did all this after disconnecting the battery for a while. Was very low on voltage because forgot to also mention the alternator fried the diodes so had to replace that. I guess some funny things happened with the lower voltage. I also got a tune with a little more fuel to compensate for the colder temps as per Tony at Race IQ. I think you are right about the leaner AFR's Craig, Temps are 30 degrees colder since I last tested so should be a big change in the AFR and that"s what I am seeing...{I hope} Thanks for the input Loungn, Craig, and Tony at Race IQ and I will update on the results on Thursday's blast to work. Trying to get this all sorted before I throw a new rear diff in wit steeper gears this weekend.
but I would definitely look for a different culprit.
11-02-2017, 08:50 PM
#10
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your fuel pressure is 75-80 at full throttle or at Idle ? ,if your going from 10.x to 13.x for no reason somethings up and it’s not the weather,,10.x full throttle is way to rich imo,
whens the last time you changed fuel filter , if you haven’t tested the fuel pressure at wide open throttle I suggest you get a gauge and monitor under WOT That could be your problem
whens the last time you changed fuel filter , if you haven’t tested the fuel pressure at wide open throttle I suggest you get a gauge and monitor under WOT That could be your problem
11-03-2017, 07:22 AM
#11
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I have a pretty good fuel system cnterline . Number 8 feed line, inline high flow filter,Aeromotive regulator with a number 6 return line and a looped rail. Fuel pressure holds strong at around 75 psi under boost and a real time gauge takes reading's after fuel rail. Also the factory filter in tank is removed.
My fuel is 50/50 unleaded ......104 and 93 octane mixed.
My new tune down loaded last night brought it down to 11.5 AFR this morning and i think thats perfect. AFR is also recorded by a AEM fail safe gauge that shuts compressor off at anything above 13.1 AFR for safety and it never triggered. drothgeb.... I really dont know what took place and can't see temperatures playing that much of a role since I have never seen that before like you said.
What I did do though before this... and it should have no effect on anything is have a custom 80mm clutched pulley made to replace my 77 to slow the compressor down a little,take some heat out and stress on everything else since I run 1/2 mile events. My current combo is a Kleeman 168 lower and a 80 upper now.So was 15lb in heat to 14lb now in 50* weather.
It's all pretty strange who knows !!
My fuel is 50/50 unleaded ......104 and 93 octane mixed.
My new tune down loaded last night brought it down to 11.5 AFR this morning and i think thats perfect. AFR is also recorded by a AEM fail safe gauge that shuts compressor off at anything above 13.1 AFR for safety and it never triggered. drothgeb.... I really dont know what took place and can't see temperatures playing that much of a role since I have never seen that before like you said.
What I did do though before this... and it should have no effect on anything is have a custom 80mm clutched pulley made to replace my 77 to slow the compressor down a little,take some heat out and stress on everything else since I run 1/2 mile events. My current combo is a Kleeman 168 lower and a 80 upper now.So was 15lb in heat to 14lb now in 50* weather.
It's all pretty strange who knows !!
11-03-2017, 11:00 AM
#12
MBWorld Fanatic!
Had I known you did not have a stock fuel set up I would have never responded lol, triple check your work is All I can say
11-03-2017, 07:59 PM
#14
will quote sicamg's comment that already addressed everything you mentioned below. I have a pretty good fuel system cnterline . Number 8 feed line, inline high flow filter,Aeromotive regulator with a number 6 return line and a looped rail. Fuel pressure holds strong at around 75 psi under boost and a real time gauge takes reading's after fuel rail. Also the factory filter in tank is removed.
My fuel is 50/50 unleaded ......104 and 93 octane mixed.
My new tune down loaded last night brought it down to 11.5 AFR this morning and i think thats perfect. AFR is also recorded by a AEM fail safe gauge that shuts compressor off at anything above 13.1 AFR for safety and it never triggered. drothgeb.... I really dont know what took place and can't see temperatures playing that much of a role since I have never seen that before like you said.
What I did do though before this... and it should have no effect on anything is have a custom 80mm clutched pulley made to replace my 77 to slow the compressor down a little,take some heat out and stress on everything else since I run 1/2 mile events. My current combo is a Kleeman 168 lower and a 80 upper now.So was 15lb in heat to 14lb now in 50* weather.
It's all pretty strange who knows !!
My fuel is 50/50 unleaded ......104 and 93 octane mixed.
My new tune down loaded last night brought it down to 11.5 AFR this morning and i think thats perfect. AFR is also recorded by a AEM fail safe gauge that shuts compressor off at anything above 13.1 AFR for safety and it never triggered. drothgeb.... I really dont know what took place and can't see temperatures playing that much of a role since I have never seen that before like you said.
What I did do though before this... and it should have no effect on anything is have a custom 80mm clutched pulley made to replace my 77 to slow the compressor down a little,take some heat out and stress on everything else since I run 1/2 mile events. My current combo is a Kleeman 168 lower and a 80 upper now.So was 15lb in heat to 14lb now in 50* weather.
It's all pretty strange who knows !!
