Rough Running And Stalling Corolla

September 30, 2005

The corolla i have been driving, just in the last couple of days, has started stalling when pulling up to stop signs or roundabouts etc, it has been getting worse, and yesterday it did it at every stop, and going around w ring road with lots of roundabouts was very hard! it had gotten through most of a tank of super unleaded fuel, which granted, it doesnt usually have, but would this affect it after running fine immediately after being filled, then surviving a 200+ mile journey aswell. when it was bad we made it to a petrol station and filled up with normal fuel, and from then on it wasnt a problem... any chance of that being tyhe reason, or could it be other things. there was also an exhaust rattle for a while which sounded like it mote be a rattling cat under the car, but that wouldnt just stop being a problem after a refill would it...?! if anyone has any ideas about this it would be so appreciated. its a P reg 1.6 corolla by the way

October 9, 2005

Super unleaded is unlikely to have caused the problem (but as far as I'm aware the ECU isn't optimised to use it so you might as well save your money)

Super unleaded has a higher RON number so on a car that can make use of it, it allows you to advance the timing further without knocking and therefore get more power. In a car that isn't set up for it it makes little difference hence I don't think using super unleaded could be the actual cause.

Having said that it's possible that THAT batch of Super unleaded caused the problem. The problem you describe does sound like a misfire problem and contamination in the injectors or impurities in the fuel could easily cause that. Regular will be used most and hence will cycle through the tanks faster meaning less chance for impurities to build up. It could have been the super unleaded had been sat their for ages and got water contamination/debris form the inside of the tank etc. in there that was then pumped into your tank causing a problem that was cleared/diluted when you refilled from another tank.

All I can guess at