Misfire??

I recenly posted about having the P401/P402 codes and it was mentioned about the DFPE(I think) sensor as the problem. I haven't had the chance to change it out, but this weekend my fan started up very rough, the check engine light flashed( indicating a misfire) then back to solid. Only done it while starting, but never while driving.

Any ideas or tips out there??

I recenly posted about having the P401/P402 codes and it was mentioned about the DFPE(I think) sensor as the problem. I haven't had the chance to change it out, but this weekend my fan started up very rough, the check engine light flashed( indicating a misfire) then back to solid. Only done it while starting, but never while driving.

Any ideas or tips out there??


HI
I don't want to minimize what could be a larger problem, but I have occasionally had the same problem: van runs fine, then suddenly on a given start up it shudders, idles very poorly and CE light comes on. Every time, I have shut it off, waited a few seconds and then re-started with no problem. CE light has stayed on, and it has been a cylinder 1 mis-fire. I have cleared it and moved on with no further problems. This has happened probably 3 times in 2 years. I have changed my DPFE based on CE light codes.

Would the DFPE sensor cause both an EGR flow problem as well as a misfire?

Would the DFPE sensor cause both an EGR flow problem as well as a misfire?

The DPFE only measures the flow through the EGR system. If the sensor was indicating a low flow the PCM may try to increse the flow by opening the valve for longer durations. If there was more EGR flow than required and/or some of the EGR ports were clogged you could get misfores. At idle however, there should be no flow. If the code indicates that the EGR is open at idle (which it should not be) then this could cause misfires.

My first CEL came on I had it read. It came back with both P401/P402,which to me sounds like the sensor.How difficult and how long of a procedure would it be to clean the egr ports? Is there some additive I could use to pre-treat the ports before I begin to take it apart.?

Clear codes and unplug EGR valve.
If no missfire with egr unpluged it is time to clean egr valve ports.
What engine and what mileage?
MT-2500

My engine is a 96 3.8L with 190K. I had the egr ports cleaned about 4 years ago. How difficult would it be to clean the ports? I'm not much of a mechanic, so if it is a timely job, probably bring it in to get done.

Anyone have a step by step procedure on how to clean the EGR ports?

Have you run the egr valve unplug test to see if that is the problem?
MT-2500

Not yet. What should I see when I unplug the EGR valve? COuld it just be the injectors that need cleaning as well?

unplugging the EGR vacuum line will eliminate EGR flow. (unless the EGR is mechnically stuck open.

This will eliminate problems caused by:
1-Clogged EGR ports that force too much EGR flow to one or two cylinders.
2- EGR operation at low RPMS when it should be closed.

unplugging the EGR vacuum line will eliminate EGR flow. (unless the EGR is mechnically stuck open.

This will eliminate problems caused by:
1-Clogged EGR ports that force too much EGR flow to one or two cylinders.
2- EGR operation at low RPMS when it should be closed.

So what you are saying is: If the EGG Ports are clogged,by removing the EGR lines I shouldn't get any misfire. If there is still a misfire, then what would be my next logical step to take?

So what you are saying is: If the EGG Ports are clogged,by removing the EGR lines I shouldn't get any misfire. If there is still a misfire, then what would be my next logical step to take?

Almost.....If you disable the EGR then you should not get any misfires due to clogged EGR ports. However the EGR could be mechanically stuck open. Disabling will not stop the flow in this instance.
A stuck open EGR should trip the CEL though. One additional note is that disabling the EGR should flag a code too since the DPFE will not detect flow when there should be some.

Almost.....If you disable the EGR then you should not get any misfires due to clogged EGR ports. However the EGR could be mechanically stuck open. Disabling will not stop the flow in this instance.
A stuck open EGR should trip the CEL though. One additional note is that disabling the EGR should flag a code too since the DPFE will not detect flow when there should be some.
Since prior to this event I had codes P401/402, which I think may be the DPFE , could this also cause a problem. How would I check this?

Since prior to this event I had codes P401/402, which I think may be the DPFE , could this also cause a problem. How would I check this?

a while ago I posted step by steps for testing the DPFE. Try a search under DPFE.

If your DPFE is a silver metallic case then chances are it has gone bad. It has been re-designed.

Not sure of what year Windstar you have but I noticed you are an electronics guy so this may be of interest. I drilled out the 6 rivets on my DPFE and noticed that there was a discontinuity between one of the the pins on the outside and the circuit card. I was able to re-attach and then to reassemble and my DPFE has been working for well over a year since then.

I will make sure that it is the problem first. If it is I will try to fix it.If I cannot fix it, then I'll have to buy a new one. I called FORD and they said the part is $126 CDN. DO you know where I could get one cheaper?

I will make sure that it is the problem first. If it is I will try to fix it.If I cannot fix it, then I'll have to buy a new one. I called FORD and they said the part is $126 CDN. DO you know where I could get one cheaper?

I thought it was a bit cheaper (And I am talking loonies here too). I tired Walmart (yes Walmart) as some of them have a parts counter and it wasn't cheaper. You can try Rockauto.com. How about a wreckers? Canadian Tire does not have them but I wonder if Parts Source have them. I don't know if you have a parts source in Walkerton but they are owned by Canadian Tire but apparently have more available items. There may be one in London. You could als try UAP/NAPA.

My van seems to be misiring just about once a day, but only during start-up and nothing while driving. I was told if the ports or injectors were clogged, then I should see the misfire while driving not just at start-up. Also told it sounds like a coil? Any takers on this??

MY take is.
Sounds like you need to take it to a repair shop.
There is a lot of maybe this and maybe that out there.
But you need to get it checked out to find out what it is.
MT

This is what I got from several garages.Seems that a misfire could be a lot of things, and I don't want to spend big $$ if I don't have to. Want to try some things myself(If I can) before I let them try and fix it.

Well have at it.
I gave you one simple test to help you with it which you have not done and several other posters have gave you some good information.
But it does not seem like it is soaking in.
So If you are going to fix it yourself here is some good info.
Good Luck
MT
All data DIy online repair info sub.
[url]http://www.alldata.com/products/diy/index.html

:smile:

Thanks for the info. Hopefully I can get a garage to work in as it has been snowing up here the last couple of days.I'll let you know what I find.

I've put some fuel injector cleaner in the van yesterday and so far no misfires at start-up. I also found that the connector on the DPFE had a broken pin, so I replaced that. Wait and see what happens. I will be checking the EGR valve on Sunday.Post back if I get any other problems.

I checked the EGR valve,and it seems ok. I unplugged the hoses and the van started to idle roughly. So where do I go from here?

It sounds like you are going to need help on it.
You need to get it to a good repair shop and get it checked out.
MT

I'm going to bring the van in to get the codes read( hopefully by Wed). I will post the codes once I get them.

I checked the EGR valve,and it seems ok. I unplugged the hoses and the van started to idle roughly. So where do I go from here?

Which hoses did you unplug?

Read my first post on it. You unplug the vacume hose at the egr valve.
MT

Read my first post on it. You unplug the vacume hose at the egr valve.
MT

I wasn't asking which hose needs to be unplugged I was asking what hoses were uplugged. I think pyronfld may have unplugged the inccorrect hoses since:

-There is only one hose to disable the EGR valve and he did say "hoses"
-if the vacuum line to the EGR is unplugged then the free end needs to be plugged (a golf tee works well).

I unplugged only one hose, but I didn't realize that you had to plug the hose. I will try it again
( hopefully tonight) and see what happens. If the idling become rough, what is my next step?

DRW1000
Sorry about that I missread the post.
I thought he was asking what hose to unplug.
10-4 on him having the incorrect hose off.
MT

My engine is a 96 3.8L with 190K. I had the egr ports cleaned about 4 years ago. How difficult would it be to clean the ports? I'm not much of a mechanic, so if it is a timely job, probably bring it in to get done.

Just completed this task myself on my ‘96 Windstar V6 3.8L, I had previously posted awhile back about the CEL being illuminated and having a P0304 code. I had at first changed the air filter and added some fuel injector cleaner, I also had a major tune-up and had to replace the catalytic converter. After all of this I was still having the CEL to illuminate and upon further reading on these forums I was lead to believe that the EGR ports may be clogged.

I myself by no mean am a mechanic but with the help of those several post, a Haynes manual, the proper tools and some carburetor cleaner it took me about 2 1/2 hours to remove the upper intake manifold with the other few components associated with this task to be able to access the EGR ports and thoroughly clean them. Port #’s 3, 5, and 6 were completely clogged but I cleaned all six of them. After getting everything back together and starting up the engine I could tell right away that it was running smoother and a quick trip down the road it was quite noticeable of the better acceleration and improved performance. My wife drove the van also and she immediately could tell a difference in the drivability. I am hoping that this has finally cleared up my issue and as of yet I have not had the CEL to come back on but I’ll give it a few more days just to make sure. At the very least I know by cleaning the EGR ports that I have helped make the engine run better.

Just what do you think it would have cost me to have a mechanic to perform the cleaning of the EGR ports as I did yesterday? How much did it cost me for doing it myself? About $6.00 for some carburetor cleaner and a small bag of rags...

I unplugged only one hose, but I didn't realize that you had to plug the hose. I will try it again
( hopefully tonight) and see what happens. If the idling become rough, what is my next step?

pryornfld,

When you remove the vacuum control to the EGR valve you effectively disable the EGR system. Plugging the free end ensures that there is no vacuum leak. IF the EGR is not mechanically (due to dirt build up) stuck open then it will not be able to come on and this will remove the EGR and the EGR ports from the equation. Errors will be flagged by the PCM but the test will show if the rough idle is due to the EGR system.

DRW1000
Sorry about that I missread the post.
I thought he was asking what hose to unplug.
10-4 on him having the incorrect hose off.
MT

MT,
No problem

Well the misfire is back, but not as bad as before. I think it happened only twice since I added the injector cleaner. When I had this misfire I removed the EGR hose( Plugged the other end) and it was still a little rough. If the EGR Ports were clogged, should I not get a misfire while driving as well, not just at start-up. I think I will get someone to look at the coils for me, as the weather is pretty crappy and I don't have a garage to work in. Any other suggestions out ther as to what the problem may be?