I am in dying need of anyone who has ideas on the following: I bought a 1991 Cadillac Fleetwood Sixty Special 4.9L (same thing as deville) about 8 months ago and since day one this car has always ran a little rough at idle so at first I got a tune up plugs, wires, oil, fuel filter throttle body cleaned, distributor cap things like that rough idle still there. A month later the car started running really bad and I ended up having to replace a fuel injector then about two months later I had to have two more fuel injectors replaced, after that the car ran like it was brand new for about a month then right on time a month or so later rough idle again and what feels like a miss when driving 25 to 45 MPH going faster then 45 still there but not bad at all but the strange thing is when accelerating there is no miss at all until now. Now after two months it feels like another fuel injector has gone (engine miss all the time now). After the second and third fuel injectors went I was told by my tech that there very well might be something in my gas tank that’s causing all these fuel injectors to fail. I had a 1990 Eldorado before this car and that had the 4.5L and I never had any of the same problems twice plus that car always had a smooth idle and never fuel problems and with that car I got WAWA premium gas but was later told that there gas is not that good for these cars. I always put Sunoco 93 premium fuel in my Fleetwood so it can’t be the gas I use. I was also told to put fuel injector cleaner in at every fill up plus I was also told to never let the gas level go below half a tank by my tech in case there was something in the tank. I will drop the gas tank and replace it if I must however I wonted to see if there was anything else that could cause this type of problem like a fuel injector pressure regulator? (That’s a guess) Can adding to much fuel injector cleaner and/or gas treatment cause this problem also? Note that there are no engine diagnostic codes. Please if anyone has any ideas
Sincerely Michael G
1991 Cadillac Fleetwood Sixty Special
Sincerely Michael G
1991 Cadillac Fleetwood Sixty Special
Oct 8, 2007 at 1:33 AM