Misfire dilemma...

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TJKashin

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I have had my car for about 20k miles now, it's beginning to show it's age. I developed a misfire issue and it's really annoying as hell and getting worse by the day. I changed the plugs and checked the boots, none of them were cracked. There was one that had a little smudge of oil on it, but not even enough to fill a thimble. I put it all back together and it ran great the first day down the road, now it's progressively worse and doesn't even need to get to operating temp to start the hibbity-jibbity misfiring. Seems to be only noticeable at idle in gear tho, not really prevalent at 50+ at all. I have checked all my local parts stores and nobody has the boots in stock to replace, so I figured I might try this deal...

http://www.wittydeals.com/product_info.php?products_id=90&mfg_id=13

Anyone else have any suggestions? I have read through most of the posts regarding this issue, I have a scan code reader but it only tells me there is a misfire when it happens but no cylinder number. There is no MiL light thrown when this happens either.

Thanks in advance for your help.....
 
Uh... I didn't know mark viii's were made after 98?... specially up to 2003.. maybe they're talkin about all marks?... mark mkx and all them kinda ones... if you're just gonna change the boots sounds like an all right deal... but if it's the coils too just get a hold of max 5 star... he's been pretty good to most of us and his prices are VERY competitive.
 
My boots were fine up until I changed the plugs the first time.

I had a small stutter miss that was intermittant before I changed the plugs...
After I changed the plugs I had a solid very hard missfire.

I put new coil boots on it, and it ran smooth as glass.

Sometimes, disturbing the coil boots screwsemup
 
I was just gonna change the boots, and since these included the coil-spring inside, it seems to be a good deal at $36 shipped for all 8 of them. The ones that my local auto parts stores usually carry or that they order all claim that the inner spring is not included. I figured if I am going to replace them, might as well do those as well in case they are corroded. Pep-Boys usually has them in stock, but all 4 stores in my area are out of them. Autozone is special order, Murray's didn't know what I was talking about it seems. Ford is outrageous and some of the independents can get them but they are upwards of $9 each.
 
I got mine at Advanced Auto Parts for like 4 dollars each..
Dunno if you have one of them near you or not.
 
Yeah, I had checked with Advance Auto as well, but they are $12 each and only come in packs of 2. I just can't see spending $100 on the boots.
 
Whats the part number for the $4 dollar ones?Is that just for the boot?I want to thank tjkasin for his help the other day,I figured out the problem now:)
 
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Glad to hear it, was it the fan as you suspected?

The ones I have found elsewhere that are all out of stock are part number SBP109 for $4.59 at Pep Boys. Advance shows the same part online for the same price but the idiot at the store swears they don't show in his computer.
 
Go to the one on Rt59-not on Essington-they are much better-No its the pressure switch-I met another gen 2 owner who told me how to test the problem and that was it.
 
Ahh, make sense considering I had that same problem on my mustang a few years back, didn't even cross my mind when you were over the other day.

I checked with the one in Downers Grove since I don't usually go home on Friday nights, but I can give them a call and see what they say. Thanks!!

Update..... I checked with Lee Auto Parts in Downers Grove and they have them in stock for $4.39 each (Standard Auto), so I'll be stopping by there after work and changing them out shortly after.
 
Ok, got the new boots and put them on, this misfiring has definately calmed down but hasn't subsided. It's now more like a hesiation when I accelerate. I guess I'll check the plugs tomorrow morning or Sunday morning to see if they got fouled during the last week of misfiring. Beyond that, I'm at a loss. THis weekend I will:

change the air filter
check the vacuum lines
Check the plugs

Any other suggestions? I have hooked up a handheld code reader which does tell me when it's misfiring, but no codes or specifics.
 
Did you put Dielectric grease on both ends of the spring?

If not..give it a shot.

other than that.. you may have a weak or dying coil....sorry to say.

I'd try greasing the springs where it connects to the coil and the plug first.
 
Ok, another update.

I noticed now that the boots on the two cylinders closest to the firewall had powdered rust on them. This worries me as I have not power washed my motor or done anything to get water in there. I am sure this is what is causing the misfire now. There wasn't any moisture in either of the wells or on the plugs, just a fine coating of rust on the boots. I plan on applying some dielectric grease in the morning as well as cleaning out the plug-wells.

Any other suggestions as to what I may do? I have no odor of antifreeze but I do suspect the seals on the coil covers.

So far:

New plugs
New Boots/springs

Each time the car runs GREAT for a day and then back to the small misfire at idle mostly.:confused:
 
TJKashin said:
Yeah, I had checked with Advance Auto as well, but they are $12 each and only come in packs of 2. I just can't see spending $100 on the boots.
Click to expand...

8 plugs / 2 per pack = 4 packs of boots

4 packs x $12 = $48

Where do you get $100 from?
 
Try taking out each plug and boot and reinstalling it. If it's running great and then returning to the same problem, then something may be working itself loose. Then whenever you replace something you tighten it back up which restores it to proper performance.

If a R&R of each coil, boot, & plug does it, then start looking very closely for play where the boots connect to the plug or coil (after driving enough to ensure the miss returns).
 
Luxuryrules - I should have clarified that post better. The 2 pack of boots from Advance Auto was $24, therefore a price of $12 per boot. That being a total of $96 before tax for 8 boots. My bad for not being clear. I found them at Lee Auto, Ford OEM boots with springs for $4.12 each.

I also have tried what you have said over the weekend. I had put in the new boots and the plugs and drove about 75 miles before the miss returned. When I got home, I checked the boots and checked the plugs and nothing had come loose. I am beginning to suspect a weak coil as suggested earlier in this thread. Upon inspection, one of the coils seems to have a crack in it, although I really cannot tell, it could just be a scratch. I just have to wait until I have some funds again as in the past week I have spent $350 on the car.

Thanks for your advice....
 
No worries mate, you gots your boots and I understand my math now :)

Just for S&Gs, try removing and reinstalling the boots. It's free, and it may prove me right or wrong about it. If a R&R makes the miss go away again, then something is definitely coming loose even if there's no evident play. I'm betting my above post is incorrect now that I think about it more, and here is why:
Above, it is interesting that you said there was no specific cylinder misfire code, which leads me to believe you got a P0300 Random Cylinder Misfire, is that correct? A weak coil or a loose contact somewhere will cause a very specific cylinder to misfire. Same for a faulty fuel injector or leaky injector O-ring. Since you're not getting a specific cylinder, the problem is more likely a faulty cam position sensor, clogged cat, blocked EGR passages, or a faulty O2 sensor. The CPS and O2 sensor can be tested on a unit that returns realtime data, so any friends with garages will come in handy here.
 
I think you are right. I have spent all the time and care on the plugs and boots. I greased them about 30 mins ago and took a test drive, the misfiring/hesitation started about 5 mins down the road. I do have full power when I ask for it with no hesitation, but at idle or low rpm I get the most annoying hesitation. I've also done the SeaFoam treatment as well. I have an EGR valve and PCV valve to change out this weekend, gotta look around for the 02 sensors I guess. Might as well do them all. Ford did the Transmission service for me as well as the CC recall service and said their computer detected a misfire, but didn't give me any more information than that. He said a good tune up would probably take care of it. Well, after doing the boots and the plugs, I consider that most of a good tune up.

I am suspicious of the cats or the o2 sensor as I used to get a really bad sulfur smell at WOT down the highway, usually a sign of a bad sensor or cat. I am only hoping that it's the damn 3rd cat since I wanted to eliminate it anyways. How much of a bitch are the 02 sensors if I want to do them while I'm under there?

So-

Next on the list-

EGR
PCV
02 sensors?
CPS?
 
Anyone in the chicagoland area have a diagnostics computer or know someone that doesn't want to charge me $100 to hook it up? I talked to my local ford dealer who told me that there's no way it could be 02's or EGR and that I should let him diagnose it for $109.
 
Im having a similar problem. Ive changed the boots, plugs, MAF sensonr. Im still getting a mis. Mines come and gones when she get warm. If you figure it out let me knw. thanks
 
Do either of you have Autozone or Advance auto in your areas? Also try other parts houses, those are just the two that scan cars out here.

Even without a CEL on, you may get a code, and should, given their behavior.
 
If you have replaced the boots and are sure they seat on the plugs properly, I would check the primary and secondary coil resistance on each coil.
 
I get no codes and from the scanner I have which is the same one as Autozone (Acctron Code Reader) I only get a general misfire as it happens, no explicit code though. I wish I had bought that autotap setup a couple years ago. It seems that I need some realtime data analysis here so I can see what's happening at the time of the misfire.

I have checked the resistance of the coils and they all fall within spec. I'm stuck between a rock and a hard place. I have spent all I have on the plugs, boots and previous to this problem a transmission service. I'm a backyard mechanic, so if it needs swapped, I can swap it. If it's broke, I can do my best to replace it. I'm not a diagnostician so all I can do is take suggestions and go forth with replacing the 02 sensors, EGR valve and PCV and hope that resolves my issue.
 
Are you 100% sure it a misfire? EGR, PCV, O2 ect. will not cause anything like a misfire. They may give you a rough idle, surge, poor performance.
It could also be a bad fuel injector I have seen them do funny things.
 
Yes if you could get a real time data scanner it would show which cylinder the misfire is on. Then you could go from there. If you have a mis or valve issue, you can take a piece of paper and hold it up to the exhaust and if there is a miss on a cylinder or a valve issue it will suck the paper in when that cylinder misses. Tryin to keep ideas goin.:D :D
 
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