Fuel consumption too high after mods!
Thread Starter
Junior Member
Joined: May 2008
Posts: 32
Likes: 0
From: Spain
C32 AMG
Fuel consumption too high after mods!
Hi all,
I have recently installed some mods on my C32 following this order:
Initially:
1. Magnecor wires KV85
2. Replaced OEM plugs
3. Johnson pump
One or two months later:
1. 181mm pulley
2. EC tune
Before replacing or replacing nothing it was doing average 20mpg in highway, but now can get maximum 15-16mpg driving in same conditions. I also noticed that idle is -not being weird- not so soft and noisier than before.
I was not completly sure becuase I put in it only a few miles after changing plugs+wires and before install pulley+tune, but I think this increase in FC was already after installing wires+plugs.
Plugs should not be responsible because they are OEM (in fact I expected to increase mpg after replacing them because they had more than 100K on them), so I can only think that magnecors are responsible for this.
I'm also thinking about some lambdas are failing, but as it happened right after the mods I'm leaning more to make some of the mods responsible for this.
Anyone more faced this? Any solution or some verification to me made?
Tks!
I have recently installed some mods on my C32 following this order:
Initially:
1. Magnecor wires KV85
2. Replaced OEM plugs
3. Johnson pump
One or two months later:
1. 181mm pulley
2. EC tune
Before replacing or replacing nothing it was doing average 20mpg in highway, but now can get maximum 15-16mpg driving in same conditions. I also noticed that idle is -not being weird- not so soft and noisier than before.
I was not completly sure becuase I put in it only a few miles after changing plugs+wires and before install pulley+tune, but I think this increase in FC was already after installing wires+plugs.
Plugs should not be responsible because they are OEM (in fact I expected to increase mpg after replacing them because they had more than 100K on them), so I can only think that magnecors are responsible for this.
I'm also thinking about some lambdas are failing, but as it happened right after the mods I'm leaning more to make some of the mods responsible for this.
Anyone more faced this? Any solution or some verification to me made?
Tks!
Member
Joined: Aug 2010
Posts: 145
Likes: 0
From: Moline, IL
2006 C55
What troubleshooting have you done?
Who did the ECU tune?
With the tune, it might be running too rich.
If you think it is the wires or a plug, I would say to swap things back and keep a close eye on any changes.
The best thing to do is eliminate as many variables as possible.
Yes, the wires might be OEM, but check the resistance and see how it compares to the original ones. Make sure all the wires are securely installed on the plugs and coils.
Who did the ECU tune?
With the tune, it might be running too rich.
If you think it is the wires or a plug, I would say to swap things back and keep a close eye on any changes.
The best thing to do is eliminate as many variables as possible.
Yes, the wires might be OEM, but check the resistance and see how it compares to the original ones. Make sure all the wires are securely installed on the plugs and coils.
MBWorld Fanatic!
Joined: Nov 2009
Posts: 3,589
Likes: 68
From: Texas
C63 507 AMG DA Car #19
If you raised the boost with a smaller pulley, and changed tunes.... (more fuel to accompany the added boost) then it's prob correct.
Do you have a dyno sheet after your mods showing the AFR vs RPM? That will tell what is going on......
Do you have a dyno sheet after your mods showing the AFR vs RPM? That will tell what is going on......
Member
Joined: Aug 2010
Posts: 145
Likes: 0
From: Moline, IL
2006 C55
My mistake, you said OEM plugs and aftermarket wires.
Check the wires and plugs and make sure you getting spark.
What are the driving characteristics? Give some more detail. Does it feel down on power or right on?
Check the wires and plugs and make sure you getting spark.
What are the driving characteristics? Give some more detail. Does it feel down on power or right on?
Thread Starter
Junior Member
Joined: May 2008
Posts: 32
Likes: 0
From: Spain
C32 AMG
I expected some more fuel consumption after install pulley+tune, but indeed not too much (maybe 1-2 mpg less after tune).
But as I've told, I'm almost sure that after plugs+wires and before tune fuel was already increased... maybe not too much.
It does not feel short in power, maybe not too much powerfull than before, but being honest I did not test it well after tune, just smooth driving and no more than 600-800km
What I see is that exhaust finals get more dirty now, I imagine it's not burnt fuel.
MBWorld Fanatic!
Joined: Jul 2007
Posts: 2,000
Likes: 20
From: East Bay, Bay Area
2002 C32, 2012 S550
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Thread Starter
Junior Member
Joined: May 2008
Posts: 32
Likes: 0
From: Spain
C32 AMG
Lambdas are not a common fault, right? Plug-in into diagnosis will tell if lambdas are ok?
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