rough idle and drop in MPGs
 

Hello. I have been doing a lot of reading and researching on here and many other forums,but nothing fully describes and answers my question.

First: two winters ago my 04 civic value package started idling rough during the cold months at start up and would go away after it was warm. And went away once it warmed up.

Second: This year it started to do it till this summer I noticed it was even worse. You could turn on the A/C on and it would bog down and shake the entire car and if you put it in gear you wonder if it would stall out and it has twice.

Third: This past month I have noticed it will start running rough when I am sitting at stop sign even after its fully warm and been running for about an hour. Oh and these last two tanks of gas my MPGs have dropped from 34 to 29.

This issue is the worst at first start up when the motor is at its coldest point. Like in the morning and leaving after work all day with it sitting there.

I have gone through and changed the spark plugs and air filter. That has been my starting point.

Sorry so long and thank you in advance.

Car is a 04 Honda civic 1.7 value package so basic car with 231k

Re: rough idle and drop in MPGs
 

Good summary on idle issues here: https://www.civicforums.com/forums/3...e-posting.html