Flashing CEL! Help

I've read all the flashing CEL threads and it seems this occurs when something might be potentially damaging for the catalytic converter...

Maybe one of you guys might be able to put all the pieces of the puzzle together. Here is the long story.

CEL light has been on for months and months now. Got it scanned like 10 months ago and the error code was MISSFIRE ON CYLINDER 3 (p0303 if i remember correctly). I changed the plugs and wires. The light stays on...The light is ALWAYS ON....
Sometimes, the van idles ok and sometimes it idles a bit ruff and sometimes, it idles a bit ruffer at red lights that it ALMOST dies on me. But it's not THAT bad.....hard to explain...it's sort of an annoying idle/vibration in the peddals....but it's not blucking and choking!

Sometimes, when I try to do a 3 point turn or backing up in a parking spot and the van would stall (it seems a bit like the van stalls when the power steering is asking too much and I’m under 1000rpm).
Every time it stalls, it ALWAYS starts back up again.
Sometimes it takes a bit more time while cranking it for it to start, sometimes it starts right away.

Stalling seems to happen more often when it's humid (raining) and Cold outside....When it was REALLY cold last winter (Québec, Canada) I had to punch the gas and crank it for it to start in the morning.

Anyways...something new happened this week, while sitting in my running van in the Park position, after a few minutes, the CEL started flashing. When I drove off, it stopped blinking and went back to it's "usual" state: ON

With all of this, I'm thinking changing the coil pack but really...I don't want to change it then still have the same problem...you know....
I'd like to try all the "quick fixes" first....Anybody has ideas? :-) Sensors or EGR valve or anything I need to clean!! Come on! I’m sure(hope) it's not the god D%$&# coil pack :-)
I gave you guys all the peices of the puzzle, now make it work!! lol


Thanks for the input guys!!

Of course a misfire on cylinder can be caused by a lot of things. Changing the plugs and wires was probably a good start. Ensure that the rest of the ignition system is functioning okay. This includes the coil pack. The humid comment makes me think the ignition system still needs testing further.

Next I would suspect the EGR system. I don't know the year of your Windstar but there are EGR port clogging issues. Perhaps your numbers 1,2,4,5 and 6 are clogging but 3 is clear and thus the EGR flows more to #3. This could cause a misfire. Bad idle can also be the EGR open when it should not be.

I suspect you need to get the codes read again. Perhaps a new code has popped up. I know it costs to get them read and it may be worth your while to buy a code reader. I bought one from Canadian Tire for under $200 and it is good for all OBD11 compliant vehicles.

You are correct that when the CEL flashes there are damaging circumstances for the cats. This is in the form of excessive unburnt fuel entering the exhaust.

Good luck and post again and we will continue to offer opinions.

(Go Team Canada!!!)

Sorry, had forgotten to mention that the van is 1996 with 175 000km on it.

Are there any tests I can do myself for the ignition system or should I bring her into a garage?

Do you know any good sites that give detail on how to check/clean the EGR? :-) Is 1996 a problematic year for the EGR?

Thanks for the input!

Dan

I am not too up on ignition testing but I think that if you run your car on a dark moonless night you may see a blue haze indicating that energy is going to ground via a different path than the sparkplugs.

I have a TSBfor the EGR ports but it is not for the 96s.

I think if you do a search in this forum you will find the tests you need.

I still think you need to ensure that more codes have not crept up.

Get the haynes book for your van I did and just did the ignition tests basic stick one probe here and the other there and read the numbers. In the haynes book it is in section 5-5. For windstars 1995 to 2003. $21.00 for the book at canadian tire.

Oh sorry you are going to need a multimeter same store canadian tire I think they are $15.00. Also a 12 Volt test light.

You've been driving the van for nearly a year with the CEL on & sometimes flashing!?! :eek7: :uhoh: More power to ya! Seeing as the van has not self-destructed yet due to a blown head gasket, or you have not fouled a catalytic converter due to a misfire, I'd guess you have plugged EGR ports / EGR issues. Common issue with a high mileage 3.8L.
G/luck
Joel

There is ONE EGR port in the throttle body not one for each cylinder.

A cylinder misfire will not melt the cat(s). I used to think this too.... leave it to the internet and MIS-information. LEAN melts cats, not rich.

It is relatively common to have cat problems around 75,000-100,000 miles 121,000-162,000 km, so that could be your constant light (catalyst efficiency).

Straight from my owner's manual:

"Light is Blinking

Engine misfire is occuring which could damage your catalytic converter..........."

It also goes on to say:

" Under misfire conditions, excessive exhaust temperatures could damge the catalytic converter....."

...A cylinder misfire will not melt the cat(s). I used to think this too....

Pumping raw fuel into a cat (with good catalyst) will most certainly cause the unit to overheat. Over heating the cat will eventually sour the catalyst, rendering it useless. This process can happen in as little as a few hundred miles in some vehicles to 1000's of miles in others- depending on how the catalytic converters are sized for the application.

Joel

Nope.

According to the engieers at FORD, LEAN overheats cats. They cannot even react properly much richer than about 11.5:1, so they go cold. Why do they dump fuel in during WOT? It's called enrichment, and it IS NOT to improve power, but to MAKE SURE the cats don't get too hot.

At full power, anything leaner than about 13.5:1 will rapidly melt a cat. The "game" is to balance AFR for cat life (rich), emissions (14.7:1), and power.

I've been intimately involved with tuning many dozens of Ford products. I can tell you that if you do NOT richen up the AFR you WILL melt the cat(s) right there on the dyno. Interestingly enough, you will likely melt the pistons as well.

I'm with you on the lean burn thing. Running too lean will cause excessive combustion chamber/valvetrain/exhaust temps. I totally understand where that will overheat / overstress an exhaust system & cat. Overloading a cat with too much fuel will cause actual *burning* inside the cat, when it should be only a *chemical* reaction of the gasses within the unit. This will also cause excessive operating temps & melt the substrate material (ceramic) in the cat which allows the paladium catalyst to do it's work. I'm no expert on this topic, but I have first hand experience- that a misfire will overheat & ruin a cat in short order on a newer (dual cat) isuzu V6 or GM V6 ( :banghead: ). I also know from the plants I operate for a living, too much fuel= a HOT short lived cat. I've seen it happen.

Joel

I had this same problem on my 98 windstar with a 3.8 liter engine.
You should clean out the egr assembly that is located on top of the intake. I had to disconnect the air filter assembly from the main engine body, disconnect a couple of electrical connectors, then remove or 12 bolts that are located on the top fo the manifold. The lift the assemble up and I could see each of the holes were plugged except #3.
If I can find a picture I'll send it.
Hope this helps.
chieko

http://groups.msn.com/FordWindstar/shoebox.msnw?action=ShowPhoto&PhotoID=24

Look at the top center piece under the text " Rubber elbow connection..." the black intake body should be removed and then you'll see the plugged up egr ports on the intake manifold. You'll find that all of the intake cylinders ar plugged excep #3. You should pull all of the dirt out and don't push it in. I had to use a household vacuum.
Chieko