Windstar misfire

[atmk631]

Hi, I have a 96 windstar with a 3.8 and around 130000 miles on it. When the engine is warm and restarted the idle is rough(sometimes), no problems with a cold engine or when driving. Codes show misfire on #1 & #4. Occasonaly a system too lean (left bank) shows up. As I said this does not happen when engine is cold and I would like to have this figured out before my emissions test next month. I have changed plugs and wires. Any Ideas, Thanks

[mazdatech177]

tough to say... could be an ignition coil breaking down, they tend to do that after a little bit of a heat soak. as for the lean code, id fix your misfires first and then take it from there

[UncleBob]

you probably have two seperate problems. I would bet money you have a vacuum leak, which isn't too uncommon on this motor, either coming from the upper plastic intake plenum, or a popular spot is the PVC rubber hose likes to deteriate. At work I have a smoke machine which makes finding such problems very easy.

The other problem you are having, is due to the EGR system. These engines, just like the ford 4.2L V6, has individual EGR ports that run the length of the intake for each cylinder. They get carboned up so that some are flowing and others are not, which causes the misfire codes. The fix isn't too bad, just pull the upper intake plenum and clean out the ports.

Hope that helps

[bm2boats]

I think Uncle Bob is right. But, I would also think about replacing the Spark Wires.

[atmk631]

Hi, I pulled the vacuum line off of the EGR and plugged it. For two days now there have been no lean or misfire codes, only P0401(insufficient EGR flow). I think I will have to clean out the EGR tubes. Do you know the gaskets, etc that I will need to complete the job. Re the possible vacuum leak, should I still pursue that or fix the EGR problem. bm2boats suggests changing the wires, but I changed them only about 6 months ago.

[UncleBob]

its up to you on the vacuum leaks. Like I said, its common.

All gaskets that are necessary to pull the upper intake plenum are the gaskets that are necessary. Assuming you don't want to just reuse them, but if you're going in there anyway, it would be well advised to replace them, since they are a common point to leak from.

[atmk631]

Thanks for the info, I will chech the vac lines as well

[atmk631]

Originally Posted by UncleBob

its up to you on the vacuum leaks. Like I said, its common.

All gaskets that are necessary to pull the upper intake plenum are the gaskets that are necessary. Assuming you don't want to just reuse them, but if you're going in there anyway, it would be well advised to replace them, since they are a common point to leak from.

Took it apart today and noticed seepage from the lower gasket, so I took lower manifold off and put on a new gasket, cleaned the EGR ports, but those nylon(plastic stuff) called vacuum lines broke like straw. Had to improvise with really small flexible vac tubing that slid over the plastic. I started it up and so far so good, I am going to give it a good run tonight. Thanks for the help.
JB