Bad Gas?

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Jpaz - when you first experienced the problem, were you just cruising along, or were you pulling uphill or accelerating (pushing RPMs above your normal cruise RPM level)?

I had a similar issue last summer, and it drove me nuts. it would start and idle fine, but at speed or accelerating above 2800 to 3000 RPMs would chug and sometimes die. I thought maybe bad gas, clogged filter, bad fuel sender, all sort of things - All the "normal" troubleshooting items yielded no luck (I had fuel, spark and air). I blew out all my fuel lines, changed the pump and sender, fuel filter and even the carb. All with no change.

I spent the better part of three weeks trying to figure it out. Turns out that just prior to the problem surfacing, I had put my new FMX in, and during the installation, I had somehow accidentally put a bend in the the fuel line behind the shock tower. Probably hit it with my elbow while loosening the old bell housing bolts. I couldn't see the restriction until I pulled off the wheel and looked from inside the wheel well. It had just enough restriction to starve the car of fuel at certain speeds. Three weeks pf pulling my hair out and it took 15 minutes to bend and splice a new section of line in.

So not saying it isn't bad gas, but just wondering if anything else was done to the car just prior that could affect air, fuel or spark at certain speeds (even inadvertently). Just some food for thought.
Hey 71coup, when this happened I was just cruising along on a flat road. Wasn’t getting on it or anything like that, which instantly made me think it was the gas. I did put a new fuel pump on and made a new steel fuel line from the pump to the carb. I made sure there were no kinks. Drove the car about 100 miles so far with no problems till I got gas. 

 
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On Power Tour 2019 I got a tank of "bad" gas. The car ran terrible until I used about 1/2 of that tank and refilled with premium. One thing I usually watch for is not buying gas at a station where a tanker is refilling the underground tanks. That'll take all the water and crud from the tanks and stir it up. 
I do try to watch out for the tankers fill the gas stations. There wasn’t one there, but could have been before I was there that day. I got gas from the same me place I always go to. But ya, now after figuring things out I think that’s what happened. Thanks droptop73 I appreciate the reply 

 

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Yeah, it was just a thought - not that I was specifically saying it was the same problem, but I would bet it's likely something small and easy to fix, once you find it (if you haven't already).

 
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Thanks again for the reply and your right, stuff like this is usually something simple. I was surprised that when I did get it running yesterday that there was hardly any unburnt fuel spitting out the tail pipes. Just a little bit like normal till it gets warmed up.

 
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John, I just took my car out for the first time this year, just a 5 mile trip around the block. When I stored it for winter I added some Sea Foam to the tank, but I might not have run it long enough for the additive to reach the carb. When I start it for the first time after hibernation, I have to prime the fuel bowl with a little gas to start it. After that it usually start no problem. What I had happen today was it ran like crap for the first mile, almost stalled a couple of times, but after it reached full temp, no more problem. So, not sure if it was stale gas in the line until treated gas got all the way through the system. Anyway, nice to get it out again. Loving the new seat belts, much more comfortable and easier to use.

 

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Thanks again for the reply and your right, stuff like this is usually something simple. I was surprised that when I did get it running yesterday that there was hardly any unburnt fuel spitting out the tail pipes. Just a little bit like normal till it gets warmed up.
That spitting is usually water. Any unburnt fuel will usually be vaporized, although if there is enough of it, like half the cylinders not firing, it can condense in the tailpipes. You can collect some of it, see if it will burn and let it set for a while, see if it separates into water and gas.

 
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In two occasions I mistakenly added E85 fuel. Once to our RX350 and another to my 4Runner. The pump looks very similar and it is hard to differentiate from the regular pump. Being EFI, the cars run well but had a bunch of oxygen sensor and misfire codes. We took the Lexus to the dealer and they confirmed it was E85 gas. They emptied the tank and reset the codes. The second time in my 4Runner, I just topped out the tank several times and clear the codes with no issues. The point is that it is very possible to make this mistake. Heck, I did it twice!! I went back to the gas station and realized that there is a subtle difference in the pumps, but if you don't pay attention it is easy to do. The both times it happened to me it was raining and I was in a rush. I assume that a carbureted car will run poorly with E85 and it could have been the culprit.

 
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I started my car today, no problems. I went and got 5 gallons of premium gas from a different station and some dry gas. Put that in and it started and ran fine. I didn’t drive it though, I had some some other things to do. I backed it out of the garage and did a little brake torque to put some load on the engine. It seems ok. 
I put 5 gallons of the gas I drained out of the tank and put it in my truck. It ran fine, so I guess I’ll have to remember this one. Or, maybe I just imagined the whole thing, lol.

 
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I did not read all the replies just my two cents worth. I am 73 and never got bad gas. Well maybe after a heavy Mexican meal.
I would go get known good gas and run a short line to a small one gallon gas container and see if it starts and runs before I would say the gas is bad. Even if they had water in the gas it does not mix would be in the bottom. Do some checking before you jump to conclusion it is bad gas. I never get gas at a station if they are filling the tanks can stir up trash and water if in the tank. I know they have filters at the pump but never stop if filling tanks.

 
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I always get fuel at this same station. If they were filling the tanks when I pulled in, I would have  of course left. I have got it running again, but like you said you didn’t bother to read the previous posts. 

 
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I’ve had this happen to me before. It wasn’t in a car but when I was snowmobiling. Got a tank full of old anti freeze and oil. Cars and trucks got it too. I was actually the lucky one cause I only got 10 gallons in my sled, was easier to get running again vs a car or truck. They were dying on the side of the road in the dead of winter. We were able to get back to the station pretty easy and drained the fuel out, pulled the cards off and cleaned them out and got it running again.

 
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So I finally took my car out for a drive yesterday. First time I have driven it since it died on me. Had no problems, ran fine and it didn’t die on me! Lol. I guess I had just enough water for it to quit running when it did. It has started every time with no problems, like normal. Still a bit baffled by this but, it could not be anything else. Thanks again for everyone’s feedback! All is good!

 
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It is odd that some areas do not have the higher octane ethanol free. You can still get leaded gas here where I live I think it is 115 octane. You cannot pump into a vehicle has to go into a can. They sell it as racing fuel only not for street use. I have a friend with a 65 GTO that he has to use it in compression way up there.
I use the non ethanol 90 in mine and my chain saw, weed eater etc. I add the Lucas gas additive that replaces the lead to lube the valves and upper cylinder. Seems to also run cooler with it in. I think this is what I add. https://www.amazon.com/Lucas-Cylinder-Lubrication-Injector-Cleaner/dp/B000ARPVOI/ref=asc_df_B000ARPVOI/?tag=bingshoppinga-20&linkCode=df0&hvadid=&hvpos=&hvnetw=o&hvrand=&hvpone=&hvptwo=&hvqmt=e&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=&hvtargid=pla-4583451663521714&psc=1

 
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Ok so I am not going crazy after all! I put some of the bad gas I drained out of my Mach and put some in my riding lawnmower. It ran for few minutes then it died. Just like my car did. 
So I drained out that tank and put fresh fuel in and no problems. Started right up and it was running like normal. Not sure what the hell kind of fuel that was, but I have about 6 gallons of it and I guess it’s going on the bonfire! Thought maybe I could mix the bad with some fresh just to get rid of it that way, but not going to chance it. I’m almost thinking it’s E85 and they mixed up what tank they put it in at the gas station. Won’t be going there any time soon. I have at least 3-4 other stations close by that have 93 octane. Thanks again guys.

 
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Here is a use for the fuel. My X wife's grandfather use to work on lawn mowers and anything with an engine. He actually heated his old dirt floor shop by pouring gasoline in a tin wash tub and lighting it, lol. First time I went in and saw it I thought he was crazy.
We use to float the river and duck hunt and out heat source was a metal can with a roll of toilet paper and pour in alcohol and light. Toilet paper was like a wick for the alcohol. Worked great to keep hands and feet warm.

 
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Ok I may have been mistaken about the bad gas. I think I had run my fuel line too close to the front of the block. I moved it some, but still had some more vapor lock issues. I have now added a 1/2 phenolic spacer and that raised the fuel line and wow! My engine really likes that after I re-tuned  it. I didn’t really hammer it too much, but it is even more responsive than it was. Anyway I’m pretty sure that the fuel percolating is done.

 
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Ok I may have been mistaken about the bad gas. I think I had run my fuel line too close to the front of the block. I moved it some, but still had some more vapor lock issues. I have now added a 1/2 phenolic spacer and that raised the fuel line and wow! My engine really likes that after I re-tuned  it. I didn’t really hammer it too much, but it is even more responsive than it was. Anyway I’m pretty sure that the fuel percolating is done.
Sounds great John. Glad you got it solved. 

 

Cribbs74

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When was the last time you checked your fuel filter? 

 
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