Originally Posted By: Char Baby
...I couldn't keep an older car idling. Added Tecron in the tank and in about 2-3 days, everything was back to normal. The engine started fine but each time I came to a stop, I had to throw the transmission into "N" and lightly apply the gas until I was ready to take off again...
The same thing happened to me with a well-maintained 2000 Cadillac Deville Northstar. I am almost certain that it was bad gas.
It was two or three years ago - I don't remember exactly - but it was the first time I filled it at a local brand name station and noticed the new "10% ethanol" stickers on their pumps. The engine started running rough at idle and I had to sit in neutral with my foot revving the gas pedal to keep it going at red lights. After a couple of days of that, I took it to my mechanic and he tested all the sensors that cause such problems electrically and all of them tested normal. I had an appointment to take it in a couple of days later for him to troubleshoot by substituting new parts - and filled it again on the way home. No additives, just a fill up on top of the 1/8 of a tank or so that was in it at the time. The next day, it was running fine again. I cancelled the appointment with my mechanic.
My mechanic later told me that several of his customers had problems about that time that he decided must have been due to "junk" being picked in the bottoms of the gas station storage tanks by the ethanol when they first added it. When I filled up again, I diluted the "junk" that I had gotten the first time and the problems went away. If I had added Techron or MMO [both of which I sometimes use] with that fill up, I would no doubt have a testimonial - but it was just the new gas.
