bad marathon gas, now runs bad when warm

quicklook · Post by **quicklook** » Tue May 18, 2004 3:54 pm

late in april bought full tank of regular unleaded at marathon station in ohio for my 92 legacy ls. car started running bad, losing power, hard to go uphill etc.

figured water in fuel.

used up tank bought another brand a liitle improvement.

then article in news said marathon refinery put lead in fuel!

car runs good when cool or warmed up, but after it gets real warm, after an hour or two, it rattles and pings like crazy. checked plugs looked ok.

marathon will pay for validated repairs, and i do have a reciept for fuel. what needs to be replaced and who should do repairs?

i am waiting to hear from marathon on how to proceed.

thanks!

vrg3 · Post by **vrg3** » Tue May 18, 2004 4:17 pm

Hmm, as far as I know, the only damage leaded fuels do to our cars is that they ruin the oxygen sensor and catalytic converters.

The oxygen sensor malfunctioning could certainly cause driveability problems like this.

You can see what kind of signal your oxygen sensor is putting out with a voltmeter or with my scantool.

Or maybe try disconnecting your oxygen sensor and resetting the ECU to see if that resolves the problem? If it does then you almost certainly need a new oxygen sensor.

If Marathon will pay for repairs, maybe you should just take the car to a good dealer and tell them to do whatever it takes to make the car run right again, and take the bill to Marathon. I would think you'd at least need a new oxygen sensor and a new pair of catalytic converters.

BAC5.2 · Post by **BAC5.2** » Tue May 18, 2004 4:43 pm

Yea, Leaded fuels have no ill-effects other than what Vikash mentioned and environmental impacts. It was originally used as a lubricant.

Race-gas is leaded.

evolutionmovement · Post by **evolutionmovement** » Tue May 18, 2004 6:10 pm

Lead was originally used actually to reduce detonation, not as a lubricant. As automakers wanted to raise compression ratios in the late teens to get better mileage and power, the poor quality fuel of the time became incompatible. The Mobil/Exxon corporation and GM (an M/E stockholder) who made half of all the cars produced at the time decided to use lead instead of the preferred alternative of ethyl alcohol since it kept more money for the douchebags despite lab results that showed lead as a toxin. Even the surgeon general of the US was involved by testifiying that the fabricated lab tests sponsored by M/E showed lead to be safe. Great Britain accepted out test results without question and thus took on the same problem. They just recently got rid of leaded fuel, but the oil company scumbags still sell it in Africa as it's cheaper than the additives they use now. Just think what the world would be like today if at the dawn of the automobile explosion we switched to domestically-produced alcohol fuel instead. If I can dig up the address, there's a 100 page report of this online somewhere. But then, they've done this again more recently with MTBE.

Steve

quicklook · Post by **quicklook** » Tue May 18, 2004 7:07 pm

vrg3 wrote: The oxygen sensor malfunctioning could certainly cause driveability problems like this.

You can see what kind of signal your oxygen sensor is putting out with a voltmeter or with my scantool.

Or maybe try disconnecting your oxygen sensor and resetting the ECU to see if that resolves the problem? If it does then you almost certainly need a new oxygen sensor.

did the reset on ecu per josh's instructions. car ran better until it warmed up after about an hour at 80 degrees.

did not disconnect the oxygen sensor though. do i do this and then reset ecu? or do i drive with sensor disconnected?

i am waiting to hear what marathon will do with me asking nice for them to take care of this.

vrg3 · Post by **vrg3** » Tue May 18, 2004 7:09 pm

You can drive with the sensor disconnected after you reset the ECU. Just be sure to wrap up and/or tie up the wires so they don't touch something they shouldn't.

quicklook · Post by **quicklook** » Tue May 18, 2004 7:27 pm

so with the o2 sensor disconneted what am i looking for? will the ecu set a code? will car drive better or worse?

also no codes were set during this whole deal.

thanks!

evolutionmovement · Post by **evolutionmovement** » Tue May 18, 2004 7:31 pm

Good luck with Marathon. This happened to a bunch of people in Detroit when I was there, only they were watering the gas. You'd drive by at 2AM and see them with garden houses in the hatch! There was a whole thing about it on the news and a lot of people incurred expensive bills, but I don't think any actually received compensation as it was too hard to prove it was the station's fault. They instructed everyone to avoid the suspiciously cheap stations (some gas was $.92 a gallon in 1996).

Steve

vrg3 · Post by **vrg3** » Tue May 18, 2004 7:39 pm

If the oxygen sensor is faulty, then disconnecting it and resetting the ECU will make the engine run normally. You will have slightly less power and get slightly worse mileage and emissions, but both of those effects will be barely noticeable.

quicklook · Post by **quicklook** » Tue May 18, 2004 8:28 pm

thanks vrg3, i will try this out tonight.

quicklook · Post by **quicklook** » Sat May 29, 2004 12:40 am

disconnected oxygen sensor. still gives same problem after it gets hot.

put new plugs in, still get problem.

fuel filter not that old, may replace.

does it sound like bad wires?

does keep me driving slower.

vrg3 · Post by **vrg3** » Sun May 30, 2004 3:51 am

I'd start by replacing the underhood fuel filter and checking the "sock" filter attached to the fuel pump in the tank. It's quite there was some other crud in that fuel or something.

You might also put some Techron injector cleaner or a little Sea Foam in the fuel tank.

You reset the ECU after disconnecting the oxygen sensor, right?

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bad marathon gas, now runs bad when warm

bad marathon gas, now runs bad when warm