Question about engine idle roughly

[anhkhoi84]

Hi guys, I have a 1996 Mercury Villager Van automatic with 134000 miles. Recently my vehicle idle pretty rough. I just changed all my spark plugs but have not tested any spark wire cause I’m pretty sure they are good. I did a compression test and all 6 cylinders vary from 121 to 125 psi (5 out of 6 are 121 psi). I also attached a video link on youtube so you know how it sound like.
The first 10 seconds of the video is vehicle at Park, next 10 seconds is at Drive, and the rest is how my air box look like.
My questions are:
1. Does my van idle roughly because of the air box cause vacuum leak? It did not idle roughly before with the same air box like that.
2. Could it be my fuel injection gone bad?

I will test my spark wires tomorrow and update. Here is my video link:

Any comment is greatly appreciated.

Thanks.

Topic

[anhkhoi84]

Hi guys, I just checked all my wires and they are all good, they are all spark as they should. My only thought for now is my fuel injections gone bad.
Please give me some input as I don’t know what to do next.
Thank you very much.

[Mathieu]

Well you need to check the engine filter first to see any grey color. Second thing, you have a idle valve that can cause rough idle and engine stall. Third thing to see is the oil and coolant level to see if the level are to low. Especially oil engine. Why you need to check the coolant fluid ? It’s simple to make sure you don’t have leak some where and a head gasket leak that pull coolant in you engine. Whit a fail head gasket, you will have hight temperature engine, engine warm up quickly and white smoke in the pipe. Small coolant leak can cause rattle in the engine. Low engine oil create idle engine noise too. If wall It’s fine, you can move on to the ignition, you can have misfire in on cylinder and buy a spark tester (seen on video). Vacuum test could be made too to be sure air and gas are ok.

[video]http://www.youtube.com/watch?v=FBUYs539cy4[/video]

[video]http://www.youtube.com/watch?v=9CPqbaSgcok[/video]

[Author]

Replies