Leaking vaccuum hose? Fuel issue?

[Chris_Law]

Hi all,

I'm new to the forums and trying this as a way to both hopefully learn and save some much needed money in resolving some of my recent explorer issues. I have a 2001 Ford Explorer Sport (NOT Sport Trac!) 4.0, 4WD. I can fix just about anything in your house, but when it comes to auto work, I'm pretty useless. That being saI'd, here's my issue(s)...

In the last several months, my vehicle has had some really rough starts first thing in the morning. It runs rough and with limited power for maybe the first 5-7 miles or so. After that, it almost sounds (and acts) like it's "clearing the pipes" so to speak. It sputters a bit, does a bit of jerking, and then it smoothes out and runs fine for the rest of the day (usually). At first I thought it was a fuel issue. It was acting get similar to when I had water get in my gas tank. So I had used a fuel treatment for a couple fill ups and it seemed to help. Also, if I started it and then drove it to a gas station and put fresh gas in, it seemed to clear up after that.

Well, lately the issue seems to be getting worse. Auto zone pulled codes and they point to a vaccuum leak? I tried looking at all of the hoses in and around the engine and none appear to be broken or damaged. But if that was causing the issue, wouldn't it be persistent through every time I drive and not just in the morning or first start of the day?

Engine is quite loud in the morning as well. At least until the issue clears up, and then the engine quiets down and runs pretty normal.

Any ideas?

Best regards,

Chris

 

[J_C]

When it first starts it needs to run richer, then after the ECM goes into closed loop mode it gets leaner, except if you have the wrong engine fault, it will not go into closed loop and stay richer which can offset a minor vac leak once the engine has warmed up a bit, but not as much when it's cold.

In a way it's good that it takes longer to run right because it gives you some time to troubleshoot. All those vac hoses coming off the intake, you can pull and plug the intake port to see if it helps. I mean that it's probably a leaking intake manifold gasket but suppose it was your brake booster leaking then all you'd have to do is pull the brake booster hose and plug it to see an immediate improvement.

Anyway the intake manifold gaskets are not expensive so if you don't find the fault elsewhere, I'd replace them. They are due to go out from old age, already.

When you get a code pulled it's usually best to post exactly what the code # is, and which engine, I don't recall if they still had the OHV 4L in '01 or the only 4L option in '01 was the SOHC.