98 E350 5.4L 56k miles.

Had 2 codes pop at the beginning of Oct for Cyl #3 misfire and Bad coil #3. I replaced those and now everything is fine. We had a good bit of rain/humidity last couple of days and now #1 has a misfire code. No coil code this time though. I looked at rain data for 2015 and the only other rain events like this were in July and January. I dont remember any misfires then.

So are my coils too old and I just need to finish replacing them all or is there some other issue I should try to chase down?

Thoughts?

 

One quick test you could try is to spray the coil and wiring connector with some WD-40 and see what happens. Remember, the WD stands for Water Displacement. It may help you determine if water is affecting/soaking into the coils.

 

The misfire DTC typically shows a dual problem or two different fault code names such as Failed Primary Ignition Circuit & Failed Secondary Ignition Circuit.

Boots that are old or cheap replacements can cause a misfire, presence of high humidity and/or condensation will expose this sort of weakness quickly. If your fault shows cylinder #1 or such first check the wiring harness connector to the COP's engine running---for this test we hope its misfiring. Pushing in on the connectors may cause the misfire to disappear---the connector is probably bad. NAPA EC259 is the cure----about $20 each. Try this with all cylinders.

IF that doesn't change the idle time to pull the COP's and inspect the boot. If they're hard or have a swelled lower end, appear to be cracked or discolored OR if the contact spring is rusty etc it wouldn't hurt to change that boot and spring.

Between these two quick and easy tests you should be able to find the source of your misfire.

HTH

 

I went out there this evening and now it is running fine. So troubleshooting it going to be harder.

Looks like those NAPA connectors require cut & splice right? I did #3 (and 4 actually) 3 weeks ago, but just the COPs.

I can replace these again on #1, but is this going to be a common problem you think until I replace them all?

 

What exactly did you replace 3 or 4 weeks ago?

Replace all of what, common problem etc?

 

Sorry, on Oct 4th I replaced the Coils on cylinders #3 & 4. I did 4 b/c of bad troubleshooting and #3 after I ran the codes and the scanner said misfire #3 and bad coil. I would have put OEM back on 4 but I broke the coil while I was trying to determine what failed.

RE: Common problem. I should have said "If i only replace the #1 coil will this problem likely show up again on another cylc? Like are these just too old and moisture will continue to be a problem for my coils until they are all new?"

Thanks

 

Okay thanks for clarifying this for me---I didn't want to assume and give bum advice.

FWIW I'm running a 5.4 with just over 275K miles on it, 2000 & all original COP's. To date none of them have failed. OTOH my 2003 E250 5.4 has had two COP's fail; 1 @ 174K miles, two others about 1K miles apart approx mileage at the time 199K.

COP's do fail but pretty much at different times---we're talking OEM or similar quality. Anything "cheaper" tends to be problematic so the deciding factor becomes saving a few dollars right now and dealing with the same thing in the near future OR spending the small extra on better stuff and have them last much longer.

No I don't recommend pre-emptively changing COP's unless they have failed. Keeping the boots in good condition is the best for your concerns. Plugs should be changed at 50K, boots at least inspected and replaced (they're typically only $5 each) if they look suspicious.

HTH

 

One other bit of troubleshooting info I neglected to mention. The misfire does not occur until the engine has warmed up just a bit. Doesnt have to be fully warmed, just like 2 miles down the road and then it misfires under all driving conditions.

 

If this were a misfire at least as Ford defines them it would typically throw a DTC. I suspect something in the EGR system or intake/exhaust is causing your driveability issues now.

 

Sorry, I was just adding more info to my OP. There were two codes for the Oct 4th event and one code for the one a couple of days ago. Both events seem to be moisture related as they happened after heavy rains and both seemed to only begin a mile or two after a cold start. After 2 miles or if the engine was already warm the misfire occurred under all conditions. The Oct 4th event was "resolved" by replacing the bad coil on the cylinder indicated by the DTC. The recent event is no longer occurring.

Obviously, I still want to fix this issue. Cant have the van acting up anytime it rains. But now that it is gone it will be harder to do any troubleshooting.

 

At some point you need to inspect all your plugs, boots, contact springs and the wiring harness connectors too.

If indeed this condition can be attributed to moisture it only furthers my idea one or more of the above parts are suspect.