Just curious- anyone have any tips on trying to diagnose problems/ find potential problems with the car through process of elimination? Say for instance- now when I step on the gas, it feels like it is almost choking trying to get fuel, and is almost dying because it is having a hard time.

Or in general, my car's idle runs a bit rough- what process do you go through to try to figure out a problem? How do you know what general category of things it could be based on the problem?


Thanks-

 

For me it's pretty much research (here and elsewhere) and experience. Also keep in mind that almost all engine problems are caused by a problem with either fuel or spark. Once you have been wrenching for a few years you'll gain some general knowledge, tips, and tricks. As for your fuel problem, the first thing I'd do is change your fuel filter.

 

The problem with that sometimes is it can get expensive. Process of elimination can get you close, but throwing parts at it can get more expensive than having a REPUTABLE mechanic fix it. There are some parts replacers out there in the mechanic field.
But if you have a good head on your shoulders, you think things through, and even consult other people that are knowledgeable, you should be fine!!!

 

...and +1 on the fuel filter

 

which year and model do you have?
it could be anything from a bad cap/rotor to bad injectors, to a clogged air filter to a bad fuel pump.

 

Keeping your car tuned up (eg: replacing filters, spark plugs, etc.) is a good habit to get into, plus when something goes wrong you can immediately rule those things out.

 

MAF sensor will make the car stumble, and feel similar to what you're describing as well. You might give a shot at unplugging it, and see if the idle improves.

As for how to figure things out, sometimes I resort to just throwing parts at the problem, but I usually try to diagnose things first to be sure I'm getting the right parts. Time, and experience help a lot with your ability to troubleshoot things. Having a FSM, or at least a Haynes manual will help some with diagnosis. Bouncing things off the org members is almost always helpful, and it doesn't hurt to befriend a real mechanic. One of my high school buddies is a mechanic (high school was a long time ago for me, but we are still friends, and he works close to where I live) and he is a treasure trove of information. He can often tell me exactly what to replace if I just describe the symptoms to him.

Sometimes you do what seems obvious, and it doesn't fix the problem. When I first got my Maxima, it had one low beam headlight out. In my many years of experience, that almost always indicates a bad bulb, so I purchased a new set of bulbs and installed them. Unfortunately, I didn't test them until after I had already discarded the old bulbs. It turned out that the problem wasn't the bulb at all, the headlight switch had gone bad.

 

Download an FSM off phatg20.net...

it has diagnostic thingies in it young grasshopper!

 

its got that process of elimination thingy majicl. So it'll tell you to start with the simplest and if that doesnt solve the problem it keeps guiding you on what to check next. I've never used it but probably should more often

 

what everyone else said.

But I've also seen a shorted oxygen sensor do this as well. (and there's a diagnostic in the manual for it. )