Multiple cylinder misfire codes

[Pokee]

I have a 2000 Windstar with 140,000 miles on it. The wife was coming home from a ~100 mile trip and all of a sudden the van started misfiring and "stumbling" she called it. The CEL came on and then started blinking. She drove gingerly the rest of the way home.

I took it in to Autozone and had multiple cylinder misfire codes - P0302, P0303, and P0305 I think but am not sure.

The plugs/wires were changed probably around 100,000 miles and I don't see how that would cause 3 cylinders all of a sudden. I started looking some of these problems up and came across the issues with the DPFE and EGR valves as well as possibly the coil going bad? I don't have a code reader to test and clear codes so any recommendations on how I should start troubleshooting?

[Pokee]

Update - since I was at the parts store this morning I picked up the DPFE sensor and EGR solenoid(? round 2" part) that I had seen can sometimes cause problems. Tried replacing the DPFE sensor and that had no effect.

[wiswind]

One thing that seems to come up, particularly around your year windstar.....is the coil pack.

Fuel filter and fuel system cleaner (Berryman's B-12 Chemtool seemed to work the best on my '96) are other things that would be routine maintenance.

One thing that I would recommend.......verify if it is.....or is not the EGR system......could be clogged EGR ports in the lower intake manifold.....which requires removal of the upper intake manifold to get to.
As a TEMPORARY test ONLY........remove and plug the vaccum line that goes to the top of the EGR valve.
Take the vehicle for a drive......do you get the stumbling and blinking CEL?
If YES.......it is NOT caused by the EGR system
If NO.....then it is likely caused by the EGR system.......in your case.....clean the EGR ports as you already changed the DPFE.

Don't forget to re-install the vaccum line to the EGR valve.
NOTE.....this test should light the CEL and store a code for lack of EGR flow......as you have disabled the EGR valve.

[Pokee]

Wiswind - thanks for the reply. I'd already taken off the manifold and tried cleaning the EGR ports before seeing your reply. The 1st and 2nd cylindar ports had a little bit of gunk but it didn't seem to substantial. The manifold was a little oily - is that normal? I just cleaned the ports with a wire - no chemical cleaner or anything.

After cleaning and replacing I turned the van on and revved it in park for awhile. Around 1500 RPM I still get noticeable misfiring and the CEL starts blinking. I also tried plugging the top of the EGR valve and got the same results.

What I did notice since I only was revving the engine was that the 2nd cylinder bump (middle/windshield) on the upper manifold was quite warm and the others were not. There was a bit of a noise - kind of a small knocking. Is this more likely a mechanical problem?

Also - I just put some STP fuel injector cleaner in - should I somehow burn up this tank of gas before putting in the Berryman's B-12 stuff with it?

[wiswind]

Some oil in the intake manifold is normal......messy, but normal.

One test that you could try......WILL cause misfire code(s)......unplug the electrical connection to the #2 cylinder FUEL INJECTOR and see if that spot gets hot like you indicate.
I do not know if it is just warmer because it is in the middle?

I am at a loss on the sounds and the hotness around #2 cylinder........could speculate on valve spring.......but it would only be speculation on my part.....I have NO experience with that........or the problem you describe.
The injectors normally make ticking sounds.....and the pushrod style valvetrain make some small sounds.

[Pokee]

Just a follow-up here. I eventually took it into the shop and they finally found a broken coil spring on one of the back cylinders.

[wiswind]

Thanks for reporting back......rare, but it does happen.....I have seen a post or so of that happening.
That is not a fun repair....on the back cylinder bank.....and if it was the #2 (middle).....you end end up with the longest reach possible.
So.....good repair to have done at a shop.

I just re-read my post where I mentioned a valve spring (and was hoping that I was wrong)....and I forgot 1 word........INJECTOR.
Where I said to inplug the electrical connector to the #2 cylinder INJECTOR........
In case someone else reads this thread.....and tries it.......you don't want to unplug the spark plug....as then you would be putting raw fuel into the catalytic converter......NOT GOOD.
I shall edit it in that post now......so that it is clear.