so my 2005 mazda 6 had been idleing rough for 2-3 weekes. i had the evap sensor replaced about a month ago and it seemed to fix the problem. 2 weeks ago it would idle rough just after starting for about 5-10 seconds and would level out around 500 rpm (i thought that was too low) 4 days ago i went out and it started really rough and died in about 3 seconds.

had it towed to the shop. they said it started when they got it. looked and found nothing, but my throttle body was a little dirty so they cleaned it. i picked it up the next day drove it to work just fine. went to go home. same thing. 2 days it sat in the rain being easter weekend the shop had closed on 12 that satuday.

same guy came out to tow it today, he thinks it's fuel pump. he said it started for him the first time he came to tow it, but that it had been sitting in the sun so it probably heated up and pressurized my fuel. he said it idled like it was going to die so he gave it some gas and it stayed on.

 

Is this a question?
Is the check engine light on? What codes are present? What codes did you have before when they replaced the evap sensor?
How many miles on the car?
Almost sounds like a bad coil.

 

Does it only idles rough? Runs fine over all? Any hesitation while driving? Any Check Engine Light? Might be a vac leak.

 

91,000 miles, no cel since replacing the valve. Before that I was pulling p2187 system too lean at idle. after replacement valve it idles a lot better just not great when it was first started in the morning.

 

Would a bad coil effect it while the car was running? Well it doesn't start at all right now, but when it did it ran pretty great. A couple weeks ago I did have a hard time accelerating in 1st gear. Only at 2 consecutive stop lights. But then fine.

 

A bad coil would make it run rough, but you should get a CEL with misfire codes. YOu said you had evap sensor replaced, but theyn you said you replaced a valve. Those aren't the same thing. I tghink you need a new mechanic that can get to the bottom of this. Your current situation sounds similar to what my car was doing when the engine blew. Nothing that several thousand dollars won't take care of.

 

Sounds like you have a vac leak. The car cannot maintain idle if you do. Check all hoses connected to the intake manifold and see if theres any cracks or breaks. Crimp or collapse any hoses manually to see if it improves your idle. If it does then thats your source. Spray seafoam around the intake manifold to see if that improves the idle.

A huge vac leak will also prevent your car from starting.

I might be new but I've been on the 6 forums for years and owned my car since 03. I even rebuilt the motor.

You would know if it's a bad coil. The car can also maintain idle with a bad coil (its not best but won't go to the point where it dies). There are times where the coil will only cause hesitation and no CEL. Or will get a CEL under heavy load.

 

unless its minor, I don't work on my car. I'm a chef I know fish. When I say I replaced I mean my mechanic replaced. Anyway I did move about 30 miles from the guys that always worked on m my car and I do believe I need a new one, now they are saying my f fuel pump is bad. I feel this should have been easier to figure out. I get the car back friday, let you knoe if its still running funny. I really need a new grease monkey.

 

Check your PCV valve if the intake was dirty. might be oil getting sucked the wrong way. Recommend checking/changing PCV with every oil change.

 

Try cleaning the throttle body and see if it helps. When the t/body on our cars get dirty, the car tends to do some really weird stuff.