Help with diagnosis

[03Mach1]

2003 Explorer 2wd 4.0 SOHC, not FFV. 72,000mi.

During the winter, if I started it up after it had been sitting, for example in the mornings, if you didn't let it sit and idle for a few it would want to shudder and die. For instance if I started it up buckled my belt and put it into Drive and tried to pull off it would try to shudder and kill. I am in South Louisiana so winter temps we are only talking maybe 40 deg.

Fast forward to now. Since it is summer again the cold start issue does not happen anymore. Over the weekend I replaced all of the spark plugs, Spark plug wires(one of them broke while changing plugs) air filter, and was going to change the fuel filter but low and behold Pep Boys gave me the wrong one. I am going to swap the filters out and replace that over the weekend. Now what really has me is before you would feel a very slight shudder in the truck while stopped at a light or something. It would be intermitent and really if you aren't aware of it you probably wouldn't notice it. I figured once I changed the plugs and air filter it would run better. Wrong, now it shudders at idle constantly. If at a light or sitting in park every 30 seconds or so you can feel a little studder in the engine.

On top of all of that I also have a rattle noise coming from under the truck in the front. This rattle noise also seems to corespond to the shudder, like when the engine shudders the rattle sound changes a bit. I have searched and seen posts about the heat shield on the converter so I am going to check that out over the weekend but other than that I am stumped.

Anyone having or had similar issues?

 

[F1EA]

If it still does it after you change the fuel filter, check the Idle control valve and the MAF sensor. There could also be a vacuum leak due to a small piercing on one of your engine hoses. (You may also scan your system for errors).

 

[noles4life002]

2003 Explorer 2wd 4.0 SOHC, not FFV. 72,000mi.

During the winter, if I started it up after it had been sitting, for example in the mornings, if you didn't let it sit and idle for a few it would want to shudder and die. For instance if I started it up buckled my belt and put it into Drive and tried to pull off it would try to shudder and kill. I am in South Louisiana so winter temps we are only talking maybe 40 deg.

Fast forward to now. Since it is summer again the cold start issue does not happen anymore. Over the weekend I replaced all of the spark plugs, Spark plug wires(one of them broke while changing plugs) air filter, and was going to change the fuel filter but low and behold Pep Boys gave me the wrong one. I am going to swap the filters out and replace that over the weekend. Now what really has me is before you would feel a very slight shudder in the truck while stopped at a light or something. It would be intermitent and really if you aren't aware of it you probably wouldn't notice it. I figured once I changed the plugs and air filter it would run better. Wrong, now it shudders at idle constantly. If at a light or sitting in park every 30 seconds or so you can feel a little studder in the engine.

On top of all of that I also have a rattle noise coming from under the truck in the front. This rattle noise also seems to corespond to the shudder, like when the engine shudders the rattle sound changes a bit. I have searched and seen posts about the heat shield on the converter so I am going to check that out over the weekend but other than that I am stumped.

Anyone having or had similar issues?

Could it have anything to do with the PCM stickied on the top of this forum? Is your PCM updated to the latest release? I had this done on my X for like 35 bucks. I was stalling in cold weather, but I have yet to since the update 2 months ago. It hasn't been as cold, but I think the idle is smoother.