I have a 1995 Saturn SL with 353,252 miles on the odometer. The engine is from a 1998 Saturn. Anyhow, for the last two months my car has been randomly dying while idling. It always starts right back up but it has become more frequent and of course very concerning for numerous reasons. I have noticed that I am getting lower than normal gas mileage and occassionally actually smell gas. My check engine light is not on so I haven’t been able to pull any codes recently but it doesn’t pass emissions on an inspection and it has always been due to codes P0171 and P0174 which of course is the fuel being too lean. I have changed the MAF and O2 sensor and it remains the same.
I am by no means a mechanic and really don’t have anyone to assist or do work for me nor do I even have the money to take it somewhere for any kind of work. I have googled this so many times and of course the same things keep coming up but I am really hoping to narrow it down as closely as possible due to my lack of finances and mechanical know how.
I don’t mind doing the work myself, if possible, I just don’t really know where to start.
I know that there are many different sensors that it could be, possibly the fuel filter but with it being inside the pump I am a bit more hesitant to mess with it without a new fuel pump nearby. I have heard that it could possibly be my injectors as well as my catalytic converter.
Is there any way to narrow it down farther?
First thing, find the pressure regulator on the fuel rail. Pull the vacuum hose off and crank the engine. If fuel squires out, you regulator is shot and must be replaced. Check and see if the car runs OK and has quit throwing codes.
Next, you need to hook a pressure gauge to the fuel rail so you can see if the pressure is within spec. You may be able to get a free rental a the auto parts store. Around 48 psi is what is in my head but a google search should give you the range. I there is inadequate pressure, the regulator may be bad, the fuel pump may also be bad. Drive around and see if the pressure stays up, especially under full throttle. If the pressure doesn’t hold, the pump is probably bad.
You also want to search for intake vacuum leaks. Plug in a vacuum gauge to the engine. If it is steady and is a steady reading of about 16-19 inHg at idle it likely has no vacuum leaks. If it is bouncing all over the place and reading 12 inHg or so, you have a vacuum leak.
If you get that far and still can’t find the problem, post back with your progress and we will try and help.