Killed 171 and 174 codes, now have P0304

Hey guys,

Back on Labor Day weekend, I successfully performed (with much additional help from you guys) the 171/174 overhaul found here: http://leckemby.net/windstar/windstar01.html

We passed emissions, and never saw the CEL again until earlier this week.

Wife reports that the engine is chugging and shaking as she idles and drives low speeds (like taking our daughter to school). She doesn't notice it at higher speeds, but it may just be unnoticeable.

I tried to read the codes, my device wouldn't even power up. Turns out the fuse for the computer link was blown (what would cause that?) and so I just put a new fuse in, and pulled P0304, which I'm determining is cylinder 4 misfire from what i've read here.

I've followed several threads, and I'm seeing everybody saying to do plugs, wires and coils, and then to perform the big overhaul listed above, as clogged EGR ports are likely suspect.

UG! I don't wanna do all that again!!! Took me 18 hours. I did change plugs and wires, but not the coils. I've never so much as changed an air filter before that day, but I studied the instructions for 2 weeks and decided I could tackle it. The van has ran AWESOME since then, so I thought I had won. Oh, I also changed the EGR valve and the sensor while I was in there too... There was no evidence they were toast, but I just did it to not have to do it later.

I don't really know what to do. If I have to do this whole procedure again, I'm going to have to scream. And take a day off from work. And it's getting frickin' cold outside.

Is it damaging our engine to drive with a misfire?

Should I try one of those seafoam things I've read about, would that help clean out the EGR ports? I'm wondering if I jostled some crud loose that I didn't get out of there, and it's fallen in and causing issues.

Any advice would be greatly appreciated. I have no money for mechanic work right now, and I have very little time to tear apart the engine again :(

Farns

"Coils" are all in 1 unit.
There are 3 coils.....each one has a spark plug at each end.....each coil firing 2 spark plugs.
The 3 coils are molded into a rectangular epoxy body with the 6 spark plug connections and the PCM cable connection all in the top of the unit.
It is kind of hard to get to the coil pack, it is located under the cowl (the plastic part between the windshield and the hood) on the driver's side.

On the 1999 and newer windstars, the coil pack is a common fail item.
The epoxy body develops a crack and the high voltage arcs through the crack.
With this type of failure, the coil pack can ohm out correctly, but still be failing.
If you have already changed the spark plugs and spark plug wires, I would certainly replace the coil pack first.
It is possible that you somehow damaged a spark plug wire during installation or some other mishap.

Having had experience in crossing spark plug wires over the years.....I prefer to have ONLY 1 unplugged at a time.
If you can move them from the old coil pack to the new coil pack ONE AT A TIME, you are less likely to plug one in the wrong place.

I am pretty sure that the procedure that you followed for the isolator bolt process has you check the EGR ports.
If you checked them then.....then they are fine now.
They will NOT have clogged this fast.......they clog over a period of time of the vehicle being in operation.

Spark plugs, the best plug to use is a double platinum Motorcraft or AutoLite brand that is listed for your year.
The multi-prong Bosch plugs that they have on display at many auto part stores have been reported to cause misfire issues in the windstar, so they are not a good choice for this application.

Another thing to double check would be the linkage between the IMRC actuator and the IMR shafts.
They will show this in the procedure pictures that you were following.
The nylon clips that hold the rods at each end can fall off.

ok, so when I did the wires and plugs, I actually DID pooch the order of the cables, I was super careful, and then I got distracted, and lost track of what went where. I got out the manuals, searched online, and felt 100% confident I did it right. It's ran nice and smooth for probably 1500 miles. If I messed that up, I'd know it right away, correct?

So assuming the wiring is right, and if I need a new coil pack, looks like $65 is the price tag on that. I can remove the cowl and stuff, I felt pretty comfortable with that last time. Is there a way to test this part and confirm if there's an issue before I spend the coin?

If I damaged a plug or a wire in the replacement, I would also know that right away wouldn't I? It was my first time doing that, but I used a torque wrench with the right setting, and have a plug drive with the padding up in there to protect the pin, and I used the KY jelly stuff they give you at Autozone to put on them. I used Autolite Double Platinum plugs.

I did clean out those ports pretty good, I have some before and after on my facebook page, I don't know if this link will work or not, but you can try it:
https://www.facebook.com/media/set/?set=a.10150780664715702.730005.519275701&type=1&l=6ad5e11576

i'm not sure what an IRC Actuator or IRM shaft is... can you give me a little more detail there? I 'll check that out.

But the thing I'm most worried about at this moment... while I'm trying to figure all this out... am I trashing the engine to still drive it? I mean, it's to my kid's school and back, the grocry store... no long hauls...

To test the coil pack you'll need to take it out and measure resistance across it's terminals but as wiswind said, if the body of the coil pack is cracked, the tests will be OK and you still have a bad coil. Just remove it and take a look at the back of it. You might see some cracks on it; by the way misfire at cylinders 4 and 6 seem to be pretty common when the coil pack is cracked. The resistance specs for the primary and secondary windings in the cil pack has been posted in the forum, I'll see if I can find it for you.

About the IMRC actuator, it's the black box located right behind the alternator and has two metallic linkages running a set of butterflies on the lower intake manifold. Each linkage should have a plastic clip at each end; these can break because of heat and the linkages end up being loose or sometimes they fall off on the road. You can buy replacement plastic clips at most autoparts stores under the HELP! brand, I found metallic clips that fit with minor effort under the same brand at Autozone.
When the IMRC linkages are loose the most common symptom is a lack of power when under load (like overtaking a car or going uphill on the highway).

Oscar.

EDIT- I forgot to say that driving with a heavily misfiring engine can damage the catalytic converter since fuel is going into it instead of being burned in the cylinders. When the misfiring condition is severe enough to damage the cat converter the CEL will start flashing to alert the driver. However you should fix your problem ASAP to prevent that case. Cat converters can be expensive and dealing with rusted exhaust pipes is always a big pain!

Just found this:


Guys,

Basically, I want to know if I should replace the ignition coil pack.

We have a 2000 Windstar, 3.8L V6 with 131,000 km.

The spark plugs were changed with Ford OEM ones about 10,000 km ago.

Wires and ignition coil are still original.

We have an intermittent misfire on number 5 and 6 cylinder. I hooked up my timing light to each wire and watched the strobe.

CEL is not on. My scanner shows no codes. It's not stalling. It doesn't feel like it's going to stall. You have to feel for the misfire to know it's there.

I cleaned the MAF a week ago.

Tonight, I pulled the wiring harness off the ignition coil pack. The readings between B(+) and the other three connectors were 1.3 ohms, 1.8 ohms, and 1.8 ohms. Haynes says reading should be between 0.3 and 1.0 ohms.

Between the coil tower pairs, I was getting about 13.6 K ohms. Haynes says reading should be between 6.5 k ohms and 11.5 K ohms.

I didn't have time to swap any wires (it's late and getting dark).

What do you guys think. Is the coil bad?

Thanks.

ok, I have the coil thingy pulled... I took a sharpie and wrote the sequence of the plugs on the frame of the car, and on the top of the plugs, so I should be good there.

Looking at the pack the way it was installed in the van, there's a sticker indicated which plug goes to which cylinder. It looks like this:

1 2 3
5 6 4

On the underside of the device, is a beige resin or epoxy or something surface... was this what you were referring to? Because there is an inch-long crack in that, directly beneath and between #s 2 and 3.

Now if there were arcing, would I see some burn marks?

Do you guys think this could be the guilty party?

I've got one on hold at autozone for $65... Sucks to spend it, but if this is the fix I'm a happy camper. I can't go for a couple hours, when my other car gets back... so I'm hoping to get some wisdom from you guys before then :)

Thanks in advance!!

farns

On the underside of the device, is a beige resin or epoxy or something surface... was this what you were referring to? Because there is an inch-long crack in that, directly beneath and between #s 2 and 3.

Now if there were arcing, would I see some burn marks?


Hi farns,

Right on he spot! Good job on finding that crack.

I'm not sure but if that's the case, you might find some burn marks on the chassis where the coil pack sits.

In any case that crack WILL cause you problems and is surely causing your issue. In the rare case that this should not be the current problem IT WILL in the near future.

It sucks having to spend the money but the best advice is to buy it or you might end up spending more money on having to get a cat converter too. If it makes you feel better the same coil pack in autozone is a bit more expensive over here.

Oscar.

Ok! New coily thingy installed... Van started. (always a fear for me....)

So I don't drive it enough to know the "feelings"... but my wife will drive it tomorrow and tell me if it feels any better. It is rough on the idle for sure... but I *think* it was more rough before. It's noticable though still.

The CEL has not returned, I didn't clear the code w/ my reader, I guess unhooking the battery did that, right?

I hooked my reader to it before starting it, and read while running... nothing. Would it throw a misfire code right away, or would it take the typical CEL cycle time and miles for it to register?

No scorch marks on the mounting block.

So it runs, but I just don't know if I fixed it or not :)

oh one thing I forgot to mention yesterday...

Would an issue such as this cause a funny smell from the engine or the exhaust? When I pulled back in the garage from my test drive, I thought I smelled a strange odor. Could have just been a smell on the street, or something... but I'm suspicious of everything at this point, you know?

It wasn't like exhaust, it wasn't like gasoline... it was more like a hint of sulfur, or spent gunpowder... I don't know. I didn't smell it very long, and couldn't really get a good bearing on it. Just thought I'd mention it in case it was a clue. I really needed a pregnant woman to help me sniff it out... my wife could smell things a block away when she was pregnant. Oh well.

Wife agrees, still rough on the idle, but she says it is much better. Put a few more miles on it today, no CEL yet...

Hi farns,

The smell from the exhaust can be either a bad cat converter or unburned fuel going into the exhaust. In your case I would say the misfiring is causing it.

When you installed the new plugs and wires, where did you put the dielectric grease. At the actual electrode or coating the inside of the wire boot. If you used it on the electrode then that would cause the van to run rough and possibly cause the misfiring.

Since you're sure the wires were installed in the correct way and if the problem is not the grease, then I would look for either a vacuum leak (the hoses behind the manifold) or a fuel delivery problem:

- Bad Fuel Pressure Regulator (remove the vacuum line on top of it, if fuel comes out then you need a new FPR. Also make sure the vacuum line is in good condition and properly seated. I personally like to use zip ties at each end to make sure is not leaking)
- Clogged fuel filter (easy to replace, sits under the driver side of the van and needs no special tools).
- Weak fuel pump (you'll need a fuel pressure tester available for rent at most autoparts stores).
- Clogged or dead injector. (Stick a long screwdriver on each injector. put the opposite side of it on you ear and listen for a ticking sound from each). Another test is to disconnect the injectors, one at a time, and listen for a slight drop on RPM's (about 50 RPM). If you disconnect one injector and the rpm's don't drop you've found a bad one.

Oscar.

Hey guys, sorry it's been so long since I responded on this. Been a crazy several weeks with the holidays and extra work hours etc...

So it turns out, I learned a $60 lesson on this one. The coil pack was not the problem (even though it DID have a crack in the epoxy, and could very well soon be a problem...). I didn't even bother to inspect the wires, because I had just replaced them. On the day after Christmas, I got my father in law to help me, we were going to look at the plugs, and see if perhaps I damaged the one in question.

So we found the wire that went to it, and were following it down to the plug, and noticed it had a huge burn hole in it. It was the wire the whole time!! I'm not sure what caused it - we think it came in contact with one of the hot parts of the motor, because the rubber was all dried out and cracking. But that's where my spark was "leaking". I went to autozone, and the gave me a whole box of new ones in warranty exchange for the one bad one. So I replaced it, ran it through that area more carefully, and we were instantly fixed. So the lesson I learned is not to assume the new parts I put in are fine. I could have spotted that very easily if I had just looked. It wasn't hidden at all. Dang.

But again, I express great thanks and gratitude to you all, you've helped me through yet another problem.

Now I'm going to go post a new thread, about how to tear apart the door to replace a door lock motor. So if anybody wants to help there, check the threads in a few minutes and it'll be there! :) Thanks again you guys, hope you're having a great new year!!!

Farns

the crack in the coil pack was not waste , it would have giving you trouble later on mine gave me trouble when it rain