Bad fuel?

[myk]

On my way to the weekly cruise I noticed that the Charger wasn't pulling smooth and strong as it usually does; under load it felt like it was struggling to make it to the next gear. I pulled over and found some of the plug wires were loose on the cap. I replaced them but it didn't help. Once i made it to the cruise I started hearing various theories including bad fuel. What exactly does that mean?

I figure in 2014 there's no way someone could be selling fuel that doesn't meet proper standards. Last week I hadn't planned properly and I ended up buying gas from some a 7-11 just to get home, and I used this same tank of gas this afternoon.  Is there a chance that I bought "bad fuel?"  And if so, just what exactly makes that fuel bad?  What experiences have you guys had with bad fuel?  Will I have to perform some sort of mechanical exorcism to be rid of this bad fuel?  Thanks in advance...

[JB400]

The amount of water in fuel determines how bad it is.  Could be caused by various things.   It could be the alcohol in the fuel attracted more water than normal, thus diluting the alcohol.  A cool night with partially filled tanks will collect moisture at the top of the tank, which will drip into the fuel, diluting it.  Also, location of the connections for the fuel truck could make a difference.  If they are in a low lying area, when it rains, water could enter into the tanks through the lids. 

How full was the fuel tank in your car at the time it was acting up?   Usually, the last 1/4 to the last 1/8 of a tank is where the nasty stuff resides.  Of course, I've bought a couple gallons of fresh gas that a lawn mower wouldn't even run on.

[myk]

The amount of water in fuel determines how bad it is.  Could be caused by various things.   It could be the alcohol in the fuel attracted more water than normal, thus diluting the alcohol.  A cool night with partially filled tanks will collect moisture at the top of the tank, which will drip into the fuel, diluting it.  Also, location of the connections for the fuel truck could make a difference.  If they are in a low lying area, when it rains, water could enter into the tanks through the lids.  

How full was the fuel tank in your car at the time it was acting up?  Usually, the last 1/4 to the last 1/8 of a tank is where the nasty stuff resides.  Of course, I've bought a couple gallons of fresh gas that a lawn mower wouldn't even run on.

Car was down to the last 1/4 of a tank, probably less. People keep telling me not to do that but old habits die hard and besides; I have this superstition about filling up my tank.

Is there any chance this sudden driveability issue could be ignition related?  Safe at home, I noticed that a couple of those plug wires are still loose in the cap.  Speaking of distributor caps, how do I know when it's time to replace my cap and rotor?  There was quite a bit of carbon build-up on the rotor tip and the terminals inside of the rotor.  Another odd thing I noticed with the distributor cap: the burn mark on the terminals from the rotor isn't centered on the terminal; it's as if the spark was hitting the side of the distributor terminal contact point instead of dead-center.  Is this normal?  Could this be affecting operations?

[Cooter]

There is a such thing as summertime fuel, and wintertime fuel. Every year, I see more and more posts about the time the change over takes place.

Fuel injection doesn't have as much problems as carbs do.

[myk]

There is a such thing as summertime fuel, and wintertime fuel. Every year, I see more and more posts about the time the change over takes place.

Fuel injection doesn't have as much problems as carbs do.

I figure a computer controlled car would be able to compensate for bad fuel as well...

[Kern Dog]

Car was down to the last 1/4 of a tank, probably less. People keep telling me not to do that but old habits die hard and besides; I have this superstition about filling up my tank.

Is there any chance this sudden driveability issue could be ignition related?  Safe at home, I noticed that a couple of those plug wires are still loose in the cap.  Speaking of distributor caps, how do I know when it's time to replace my cap and rotor?  There was quite a bit of carbon build-up on the rotor tip and the terminals inside of the rotor.  Another odd thing I noticed with the distributor cap: the burn mark on the terminals from the rotor isn't centered on the terminal; it's as if the spark was hitting the side of the distributor terminal contact point instead of dead-center.  Is this normal?  Could this be affecting operations?

If your tank is new, newer or at least in good condition, it makes zero difference how low you run it down before filling up. SOME people say...If you run the tank down to the last gallon, you are sucking up all the sediment in the tank!Wrong. Any sediment that could be in there is likely to be heavier than the fuel and would be at the bottom of the tank no matter how much fuel is in there. The fuel pickup should rest near the bottom anyway. If it didn't, you'd run out of gas at 1/2 tank or wherever the pickup sits other than at the bottom.

I have had sudden misfires happen. EVERY time this happened it was due to the MP electronic distributor. The air gap is supposed to be set to .008. I've had mine slip open to .020 and still run, but it would pop and sputter when I leaned on the throttle.

[myk]

Yes the tank is new; anything else is asking for trouble IMO.  How does one go measuring the gap between the rotor and the cap terminals?  Maybe it's time to buy Ron's distributor and ditch the MP unit...

[NHCharger]

I've had it happen to me. Filled up on the way to a show, by the time I got there car was running like shit.
One of my theory's is that there are 3 different grades of gas. Around here it 87,89,93. I run the 93, most people use 87 so the 93 storage tank isn't filled as much so there is more of a risk of contamination from condensation in that tank.
Another time out for a long cruise and car started hesitating, running poorly. When I took the carb apart the fuel bowls were full of crap. I've had to take the carb apart to clean about every three years.

[Ghoste]

Never rule out what the ethanol is doing to all of our cars.

[myk]

I've had it happen to me. Filled up on the way to a show, by the time I got there car was running like shit.
One of my theory's is that there are 3 different grades of gas. Around here it 87,89,93. I run the 93, most people use 87 so the 93 storage tank isn't filled as much so there is more of a risk of contamination from condensation in that tank.
Another time out for a long cruise and car started hesitating, running poorly. When I took the carb apart the fuel bowls were full of crap. I've had to take the carb apart to clean about every three years.

Hmm...interesting.  Do your theories about gasoline include anything about the brand name of the gasoline?  I realize it's all the same gasoline, but maybe different stations have different....standards?

Never rule out what the ethanol is doing to all of our cars.

Right.  So what do we do?  

Meanwhile, I should go to bed but this driveability problem is bothering me; I'm going to take the car out and see if burning through that tank helps any...

[Ghoste]

My suggestion is political so it won't go far.

[myk]

Well Ghoste, looks like you won't have to politicize the board right now, as I found and fixed the problem.

I love how every time something goes wrong with one of my cars I always go to the extreme, worst-case scenario; when in fact it's many times something as simple AS......a spark plug wire that melted onto one of my exhaust manifolds.  The viewing angle is so bad on the #8 plug that I couldn't see that the wire was melted onto the manifold until I physically ran my hand down the length of the wire.  Yup, all I checked was whether the wires were plugged in properly at both ends, I didn't bother to see if the wire itself was in good condition.  As soon as I peeled off the wire and taped it up the car was 100% again.

Question: will taping up the wire be satisfactory, or will I have to replace it?  I don't suppose you can buy a single spark plug wire, can you?  In any case yes, I am a complete goddamn moron...

What is my penance for making the car suffer for nothing? 

[Ghoste]

Luckily the Charger doesn't work in a traditional sin/penance scenario, she loves you and just wants you to be happy.  You have  already suffered the punishment by it not running as well as it should, now you r Charger wants to reward you for fixing it by having you take it for a hard run.

[Dino]

I'm glad to hear it's just the wire!  Now you have an excuse to get some Firecore's on that puppy.      

[Kern Dog]

If the wire is long enough, you could shorten it by cutting off the burned section and reattaching the terminal end to the wire. Grab a used boot from a junker and be done with it for now.
Regarding the air gap in the distributor: What I described is not the distance from the rotor tip to the distributor terminals. The air gap refers to the electronic pickup and reluctor that replaces the points. There is an 8 pointed "star" under the rotor that rotates with the shaft. The 8 points momentarily align with the "pickup" that is mounted solid to the distributor plate. Just like it is with points, there needs to be a specific gap/distance between these two components for a spark to occur. If the gap is too small, there is too little space to generate a spark. If the gap is too wide, the same thing happens.
I have a MP distributor that seems to randomly decide to allow the pickup to move, allowing the gap to change. Once I was taking the car to drag race it at the local strip. I poured in 5 gallons of 110 leaded but drove like a grandma to the strip. Once I got to the line, I hammered it like it owed me money. Once the rpms came up it coughed and sputtered to a measly ET. It cruised fine but faultered under a load. I was so embarrassed, I drove home after 2 passes and dug around until I found the problem.