Some cars are very sensitive to old fuel. Your car with plugs and coils that were in the latter part of their service life and fuel that is not optimal for it and it very well could be the problem. I discovered that one of my cars will toss a misfire code if I run 93 octane. Feed it 87 and it is happy.
I had a big problem with phase separation in some of the fuel I got this summer. It seemed to get screwy just by sitting in a sealed gas can over three weeks or so.
I'm wondering if the humidity over the summer made some condensation build up in the can that just kick started the process quickly or something.
kaybat
New Reader
10/24/23 1:53 p.m.
My S54 did this a few times a year(at start-up), turns out it needed a throttle body actuator(?)..Wilsons new right away.
In reply to Brett_Murphy (Agent of Chaos) :
Maybe we had some phase separation? Somewhere in there we fueled up a few times with some fresh Sunoco so I’m driving the car a bit just to flush things now.
In reply to David S. Wallens :
I read this article about it. In my situation, I put the bad gas into my lawn mower, and it ran (poorly) for a bit, then choked out completely. The carb bowl was completely filled with the water/ethanol phase.
I'd love to see phase separation among the gasoline articles you do, especially as many of us have cars with gas in them that sit around, unused, for weeks or more at a time.
In reply to Brett_Murphy (Agent of Chaos) :
Like show a real example of phase separation? Let me talk to Zach about the realities. My fear is that it might vary due to fuel, container and conditions, but let me ask.
By the way, as of this morning, the M3 starts and idles just fine.
Car is running Sunoco 93.
In reply to David S. Wallens :
Maybe talk about what it is, how it happens and how it can bit us in the ass if gasoline sits around for a while.
Tom1200
PowerDork
10/25/23 11:54 a.m.
In reply to Brett_Murphy (Agent of Chaos) :
Everything I have that sits for even a short length of time gets quality fuel. In my case it's 100 octane unleaded (available at the pump). I put it in everything from the mower to the races cars to the dirt bike................I even use it in my portable generator.
Since I started doing this I've had none of the small issues I had before.
We’ve written about fuel aging before, and see if these articles help answer some questions:
What Happens to Gasoline as It Ages?
Antioxidants, Fuel Stabilizers, and You
How fresh is that fuel?
The right fuel in the fall might help your engine start in the spring
Fuels for storage: Good, better, best
Water Is Great for Your Plants, Not So Much for Your Fuel System
Should you fill up your classic before parking for the winter?
But it sounds like maybe there are still questions about this. (For the record, I try to put Sunoco 93 in everything since, like Zach always says, a Top Tier, high-octane fuel will simply age better.)