Hesitation/cut-out on hard right turns on track
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Joined: Jun 2008
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From: Los Angeles
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
That's so weird Ryan. I've got to think that you're right that one of the fuel pumps is struggling for some reason. How to test it is the question. If they're cheap, it might just be good to replace both?
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Joined: Apr 2013
Posts: 1,506
Likes: 66
From: Sidney, BC
2009 SLK55 AMG. & 2022 GLA250 4Matic
Thread Starter
Member
Joined: Dec 2016
Posts: 90
Likes: 25
2009 C63
I'm running NA airboxes with the charcoal filters removed and K&Ns. I think stock filters might be the next step as I've read a couple posts about K&Ns causing these symptoms. Why it would only be on right handers once the fuel drops is a bit beyond me, but I think stock filters will be the next step to try.
it seems like a fuel delivery issue, but I just can't see how it would happen at half a tank of gas. I think we're just dealing with something really weird and we'll need to track it down piece by piece.
Since filters are cheap and easy, I'll start there and cross that one off the list. If it persists then I'll focus more directly at fuel delivery.
Thanks for the info gents, appreciate it!
Ryan
ps. The car was a lot of fun again at the track. Definitely need some tires for next season (I'm running Conti Extreme Contacts as this is my first year at the track with the car), but the upgrade to Motul 600 RBF and Powerstop Track Day pads certainly woke up the braking. I've now joined the 'bronze caliper' club. (I'll post a review of the pads in a separate post.)
it seems like a fuel delivery issue, but I just can't see how it would happen at half a tank of gas. I think we're just dealing with something really weird and we'll need to track it down piece by piece.
Since filters are cheap and easy, I'll start there and cross that one off the list. If it persists then I'll focus more directly at fuel delivery.
Thanks for the info gents, appreciate it!
Ryan
ps. The car was a lot of fun again at the track. Definitely need some tires for next season (I'm running Conti Extreme Contacts as this is my first year at the track with the car), but the upgrade to Motul 600 RBF and Powerstop Track Day pads certainly woke up the braking. I've now joined the 'bronze caliper' club. (I'll post a review of the pads in a separate post.)
MBWorld Fanatic!
Joined: Apr 2013
Posts: 1,506
Likes: 66
From: Sidney, BC
2009 SLK55 AMG. & 2022 GLA250 4Matic
I'm running NA airboxes with the charcoal filters removed and K&Ns. I think stock filters might be the next step as I've read a couple posts about K&Ns causing these symptoms. Why it would only be on right handers once the fuel drops is a bit beyond me, but I think stock filters will be the next step to try.
it seems like a fuel delivery issue, but I just can't see how it would happen at half a tank of gas. I think we're just dealing with something really weird and we'll need to track it down piece by piece.
Since filters are cheap and easy, I'll start there and cross that one off the list. If it persists then I'll focus more directly at fuel delivery.
Thanks for the info gents, appreciate it!
Ryan
ps. The car was a lot of fun again at the track. Definitely need some tires for next season (I'm running Conti Extreme Contacts as this is my first year at the track with the car), but the upgrade to Motul 600 RBF and Powerstop Track Day pads certainly woke up the braking. I've now joined the 'bronze caliper' club. (I'll post a review of the pads in a separate post.)
it seems like a fuel delivery issue, but I just can't see how it would happen at half a tank of gas. I think we're just dealing with something really weird and we'll need to track it down piece by piece.
Since filters are cheap and easy, I'll start there and cross that one off the list. If it persists then I'll focus more directly at fuel delivery.
Thanks for the info gents, appreciate it!
Ryan
ps. The car was a lot of fun again at the track. Definitely need some tires for next season (I'm running Conti Extreme Contacts as this is my first year at the track with the car), but the upgrade to Motul 600 RBF and Powerstop Track Day pads certainly woke up the braking. I've now joined the 'bronze caliper' club. (I'll post a review of the pads in a separate post.)
Save you self the angst and take it to someone who can tell you what it is and how to fix it.
MBWorld Fanatic!
Joined: Jun 2008
Posts: 8,078
Likes: 2,867
From: Los Angeles
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
So, just to add here. I was looking for something else on OEDiscountParts, and their system shows that the FL/BS models ALSO have 2 fuel pumps. Just thought this was interesting. They're only like $300ea so probably worth replacing on higher mileage cars.
MBWorld Fanatic!
Joined: Apr 2013
Posts: 1,506
Likes: 66
From: Sidney, BC
2009 SLK55 AMG. & 2022 GLA250 4Matic
Very interesting as the info I found said that the 2010s onward were single pump but then again Pelican Parts is saying 2 per vehicle in 2011, 2012 and 2013 so I guess there are 2 and the earlier info I dug out was not right. Good one guy!
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Joined: Dec 2016
Posts: 90
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2009 C63
And for a quick update on this issue...
Definitely a fuel starvation issue somehow. When the tank is full, there are no issues. Just above half a tank, start getting hesitation on the fast uphill right-hander. At 1/3rd of a tank, get hesitation on the low-speed right hander. Top up the tank and everything is fine again.
I ran stock paper filters and didn't get a CEL, so I'm leaning towards tires fuel pumps.
I'll get a new left pump installed (since it's only on right-handers) before my next track day in July and report back...
Definitely a fuel starvation issue somehow. When the tank is full, there are no issues. Just above half a tank, start getting hesitation on the fast uphill right-hander. At 1/3rd of a tank, get hesitation on the low-speed right hander. Top up the tank and everything is fine again.
I ran stock paper filters and didn't get a CEL, so I'm leaning towards tires fuel pumps.
I'll get a new left pump installed (since it's only on right-handers) before my next track day in July and report back...
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MBWorld Fanatic!
Joined: Jun 2008
Posts: 8,078
Likes: 2,867
From: Los Angeles
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
That’s weird. I’ve run out of gas on track twice this year, and both times it was on hard LEFT turns. The last time, once I got the car straightened out I had enough to sputter back to the pits.
