My girlfriend has a 2006 Suzuki Reno which is the hatchback version of the much more common Forenza. Mechanically they are the same car. I began to look into this car soon after I began dating her and realized it was simply a rebadged Daewoo product. I attacked the timing belt replacement early on as she had no idea when it was last changed. The old belt was all cracked up and in dire need of replacement when I did the job.
Since then it has just been a lot of small stuff, all things these cars or known for. We are now getting a new symptom. The car sometimes hesitates/stumbles when trying to maintain or gain speed at highway speeds, especially going uphill. There are no check engine lights and I have checked for pending codes. There are none. I figured a misfire would show up but no codes of any kind are present. There was an issue a while back with the evap system purge valve which I cleaned and reinstalled. I don’t know if this could be the issue but it isn’t throwing the P0496 code anymore like it was before I cleaned it.
These symptoms are very intermittent. She used to always put like 3 gallons of gas in the tank when it got near empty and never fill it up. I got frustrated and told her to fill it to the top at least every once in a while. The first time she did this these symptoms started. I wondered if she busted some varnish loose inside the tank that had not been in contact with fuel for some time. We put some fuel injector cleaner in the tank and it cleared up for a while but returned a few tanks later. It seemed to start as she was nearing the end of a tank and continued for a bit after the fill up.
I am getting the feeling this might be a fuel related issue and not the ignition system. I already looked to see if her fuel filter was replaceable and it is not. It is an in tank one that requires the tank be removed. I would do the fuel pump if I had to do this. My other thought is maybe the fuel pump is getting iffy. I am going to do a loaner tool on a fuel pressure gauge if this happens again as I am wondering about that. Also, I haven’t looked into a fuel pressure regulator but that might be something to look into.
Anyone else have thoughts on what might be causing this? I want to get some other ideas before jumping in. This car seems to be one little thing after another if you ask me. It is never anything major but annoying stuff and I guess these cars are known for this.