CEL misfire #1 rough idle

1995 Windstar LX 3.8L
newer spark plugs and new plug wires

My wife started noticing that the van was running a little rough a week ago and it has gotten worse over the last couple of days. You can smell fuel or exhuast after you run it a little bit.

The CEL has come on and stays on. Autozone scanned it and stated that it is misfiring in cylinder #1. I replaced the wires. The plug in #1 looks normal, it is new from last summer. I pulled the EGR and looked for any build up and to see if the EGR is bad. The EGR seems to hold a vacumm, I used the mouth approach.

I've poured in a bottle of techron injector cleaner in the tank and have fill the tank. I havn't driven more than 10 miles since pouring in the cleaner.

Any Ideas? Help. Thanks

This fits the profile of the classic EGR port clogging problem. The gases from teh EGR form deposits in the lower intake manifold and cause complications after a while.

To remedy this problem, you will need to pull the upper intake manifold and clean and scrape up as much of the deposits you can from the EGR nozzles.

Do a search in this forum for EGR and misfire for more details.

Thanks for the tip. What do you recommend to clean the intake? Since I'm there I might inspect the injectors. Is there something on the market to clean the injectors directly?

Thanks and I will post my results.

:) That's why I suggested you do a search through the forum. Lots of these guys have done the job in various different ways. I actually had my lower intake removed when I cleaned mine, so my method isn't really applicable in this case.

Over the counter cleaners don't seem to be very effective for the injectors, but the commercial stuff some garages use seem to work somewhat. At $50-80 for a treatment regimen, it's far cheaper than replacing all your injectors.

Does the 95's have the same 1/8" EGR ports that the 99's and up have?

Although too much EGR flow going to the misfiring cylinder would explain the problems I was under the impression that for the 95's there was a shared EGR port to the intake. Perhaps someone can enlighten me.

I haven't seen the intake on the '95 so I can't tell you for certain, but on the '98 3.8l engine, each intake valve has a split feed. One port is the main air intake with an EGR feed and the other is controlled IMRC- only open during certain circumstances regulated by the PCM.

Even though Haynes makes little reference to the EGR jets that are on ('96 and later?) 3.8's, there are a couple of photos where you can pick them out.

Chapter 1, figure 7.7b.

Chapter 4, figure 13.36b.

Perhaps I wasn't clear. I was asking if the 95 had the same EGR ports as on the 99s and up because the thread starter is having problems that someone suggest may be the EGR ports. IF he/she does not have the individual ports then this advice will not help and they should look elsewhere. The models with small individual ports have misfire troubles when a few of the 1/8" ports clog and all of the EGR flow goes to one or 2 cylinders causing them to misfire due to lack of oxygen. If the 95 has one common EGR port then I doubt that EGR port clogging is the root of the troubles.

Sorry 12ounce I think I was typing my last post as you were answering my previous question.

I wonder if the 95s had them too.

Autozone pulled code P0301 only
Things that I've tried:
1 Replaced the plug wires and swapped spark plug from cylinder one and swapped with cylinder five, did not help.
2. I measured the coil against a new one and it measures ok
3. The hoses to to DPFE appear good.
4.I put a mouth vacumm on the egr valve and it holds.
5. Pulled the plenum and inspected the intake. On the 95 the intake has individual passages. Do you have to remove the whole intake to clean the egr ports? Am I way off? I don't have a haynes book so I'm a little confused.
6. Cleaned the throttle body while I add it out.
7. Cleaned EGR passage way to the plenum body. Not clog but a little build-up. Is the EGR port where the EGR valve bolts to the plenum?IF so the port is clean.
8. I had a second injector rail from another 95 windstar I had, so I swapped the injector rails. (all injectors). No change
8. Compression checked cylinder one 150PSI
9. I took it back to Autozone and had it read the code after I cleared it and I still get P0301.

I'm ready for some professional help! Please

Thanks Bob

Wow.

I wish I could offer some advice but you seemed to have covered everything I can think of.

1)Have you considered the wiring harness to the Injector? Since we assume the injector is fine and clean (since you tried two) perhaps it is not getting the proper electrical signal or too long of a signal or something electrical to that cylinder.

2)Try disconnecting the EGR vacuum hose. (plug the hose to avoid a vacuum leak). This way there will be no EGR flow (yes codes will be set for this) but it will eliminate the possibility of excessive EGR flow to your troublesome cylinder.

3) what about the spark plug's sister plug? Apparently each spark plug fires through another plug. This means that the circuit path is a series circuit that uses 2 spark plugs. Perhaps the other one is causing a problem. The one that fires simultaneously will be the cylinder that is 180 degress off in the firing sequence.

4) Could there be a valve problem? I will assume this would be obvious but just in case. The PCM detects a misfire by detecting an instaneous change in crankshaft rotation (at least in OBD11 vehicles).

5) What about the crankshaft rotational sensor giving a bad signal?

Good luck. Post any findings no matter how irrelevant they may seem. It may trigger something with someone.

To verify EGR issue as a cause for your miss....
Remove and plug the hose that goes to the EGR valve.
Take the car for a drive (The EGR valve does not open at idle).
If you do not have the miss, then you need to clean the EGR ports (that is...if your '95 has a port for each cylinder).
There should be an "upper" and a "lower" intake manifold.....on the '95, the "Upper" is aluminum (I believe). The upper intake manifold on the '96 and later 3.8L is a black nylon "composite".
Removing the "upper" intake manifold should get you to the point that you can view, and clean the EGR ports....that should be located in the lower intake manifold assembly.

If you still have the miss, with the EGR valve disabled, then something else, is causing your problem.

Please note, removing the hose to the EGR valve WILL cause the CEL light to come on for "lack of EGR flow"

Fuel injectors DO build up crud after many miles.
I removed mine and sprayed cleaner on the spray end to remove crud....and that fixed a miss issue on my '96....This crud did not clear up with fuel system cleaning....although it is a VERY good idea to run some fuel system cleaner through from time to time......I made it to 137K miles before having any issue with crud on my fuel injectors.

I have also had the EGR port clogging cause a miss on mine....That was at just over 135K miles.

Thank you all. Please continue. I am attempting to clear up a "misfire" problem myself. I can clear up some issues for you. On myh 95/3.8 the EGR attaches directly to the plenum with no individual ports to the cylinders, just straight into the plenum right after the IAC. 2. At 110K my CEL came on. I found a rotten hose leading to the DFPE. I repaced it, and the car idled better, and after resetting the OBD, the CEL never came back on. Now my engine "stumbles" at idle. No CEL this time, just trying to address a potential problem. My next purchase will be a IAC valve, but with 150K miles on this rig, I suspect a timing chain issue, or a Cam positioner issue. Please post what you find on yours. Thank you.

Karl.
A.

CoachKarl,
If you decide to change the camshaft position sensor, you do NOT need to align it. Alignment is only needed if the gear below is replaced....or if it has been moved.

As many people read these posts other than the person who had the original question.....I include a bit more information.....

The camshaft position sensor is all that is left of the old time distributors. Looks just like the "pickup coil" that was under the rotor....which was inside the distributor cap.

Anyhow....when you buy the replacement camshaft position sensor......there are 2 little bolts/crews that you undo.....pull it off...and unplug it.....and the new one goes right on.....with tabs to position it correctly. I have replaced mine....although it was not my problem. But there are posts here about the camshaft position sensor causing problems......usually due to a cracked electrical connector. A very easy item to replace.

1995 Windstar LX 3.8L
newer spark plugs and new plug wires

My wife started noticing that the van was running a little rough a week ago and it has gotten worse over the last couple of days. You can smell fuel or exhuast after you run it a little bit.

The CEL has come on and stays on. Autozone scanned it and stated that it is misfiring in cylinder #1. I replaced the wires. The plug in #1 looks normal, it is new from last summer. I pulled the EGR and looked for any build up and to see if the EGR is bad. The EGR seems to hold a vacumm, I used the mouth approach.

I've poured in a bottle of techron injector cleaner in the tank and have fill the tank. I havn't driven more than 10 miles since pouring in the cleaner.

Any Ideas? Help. Thanks

I have a 1999 ford windstr 3.8. For 3 weeks I have been pulling my hair out over this. It has 300,687 miles on it and until then ran great and had no major probs not even an oil leak. I have replaced the o2 sensors, plugs & wires, EGR (all 3 parts), isolator bolts under plentum, injectors,cam shaft position sensor, & nothing helped much. (all of these parts except the plugs and wires where original ford parts). Today, I replaced the coil & it runs like it did when I bought it. No miss, no hesitation just a nice clean drive. My point is, has anyone ever herd of a ford winstar having this many miles on it and running this good? Also,I recommend to check the little things first I guess. K9hammer

My 98 3.8 has 270,000 and was running great except for some problems when it was wet. I just changed the spark plugs and managed to reach in from the top and get them all ok. I think the big difference with getting them from the top is you can't see what you are doing so just go by touch. As long as the engine is cold it is pretty easy to feel a spark plug or plug cap and I found all the plugs treaded back in easily. I used the NGK plugs since that was what I removed.