2000 Century-Intermittent hesitation, gas smell, rough idle

[Lyveno]

We have an intermittent problem. When I press on the gas, the car kind of hesitates--it goes very slowly, the comes up to speed. Two weeks ago, we noticed that there was also the faint smell of gas after the hesitation. The check engine light was never on.

We took it to a shop--they replaced fuel regulator and the fuel filter. Three days later, same problem. We took it back to the same shop--they replaced the fuel cap. Next day, same problem. My husband put in some fuel injector cleaner and there was no problem for several days. Last night, it happened again, although this tank has fuel injector cleaner in Shell gas. There is still no check engine light.

On the second visit, my husband talked to the tech who replaced the regulator and found that they had only done a visual inspection, found residue on the fuel regulator and decided it needed to be replaced. No tests were done.

I'm taking it to another shop tomorrow. The guy at that shop says that it's happening because I have used fuel with ethanol. I'm not so sure I believe that since I grew up in the Midwest and have used fuel with ethanol for as long as I have been driving and never had any issues with any of my cars.

What tests should this other shop do to identify the cause? What could the problem be? Could it be the fuel injectors? We have not had a tune-up since we bought it.

We just bought the car in January... it has 126k+ miles. We have replaced front cv's and transmission.

 

[Lyveno]

Ok, I was asking what tests should be done because I have already spent over $300 for a fix that did not take care of the problem. I can't afford to keep putting money into fixes that don't work. I was hoping someone could give me some suggestions on where to start, but I guess my problem must have stumped everyone.

But thanks anyway....

 

[jmil1974]

Sounds like your tech was making a (good) educated guess and throwing parts. How many miles on your car? Have you ever had the injectors professionally cleaned? The bottle in tank will prevent deposits well but not actually clean much. Your injectors are likely still fouled, along with a dirty intake. Many techs know this and simply don't want to deal with the pushback they get from customers who decline these services thinking they can simply pour a magic bottle in the tank to clean injectors. A proper injector flush + decarb involves disconnecting the fuel line and a vacuum line and actually running the car off a detergent and fuel mixture. Fouled injectors can cause all your symptoms. Injector cleaning should be maintenance but neglect and poor quality fuel often turns this into an actual repair. I'd start here since it likely needs to be done anyhow. If this doesn't do it, then you need someone actually willing to diagnose the problem and backtrack and double check previous work.

 

[dcraig1000]

pull the plugs and see what the look like. first things first. it also could be a vacuum leak. check all of your vacuum lines/hoses for deterioration/cracks/holes.