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New OEM Spark Plugs... No Go!...

I

iskoos

CEG'er
Joined
May 23, 2008
Messages
245
Location
Orlando, FL
96 Contour GL Zetec 170k

Some of you will know my case. I had a slight hesitation in the engine and when I asked the first question was: What plugs / how old is the plug wires ...

I had new Bosch Platinum +4s in there and my plug wires(Motorcraft) was about 5 years old.

I was advised very strongly that I should put OEM Motorcraft plugs at the top of my list and replace the wires because it is best to replace the plugs and plug wires at the same time...

Went to Ford dealer. $8.92 for each plug and 80.00 for the plug wires. I said thanks...
I found silverstate Ford and ordered the same stuff from them.
Each plug is $3.90 - Plug wires only $35.00 (kudos to these guys) I got everything OEM and saved %50.

I started a thread here several days ago because the plug gaps were slightly off. I was recommended to gap them to exact specs.
The specs for my car is 0.05inches (or 1.3mm) and the plugs were at 0.045inches (about 1.2mm) out of the box. I regapped them and installed everythig this morning.

How did the car run?
I had to keep my foot on the gas pedal to keep her running. After about 30 seconds, I called it off and removed the new OEM plugs and put back the Bosch +4s back in there. She started running just fine. I left the new spark plug wire set on the car. But from the way she runs I could tell, there were nothing wrong with my old wires set as well...

The car runs fine (I still have that hesitation though but it is very driveable)

Now my question is that : WHAT THE HECK HAPPENED?
You put a 4 brandnew plugs (and they are OEM not aftermarket) and car runs like a crap. And you put back the plugs nobody likes, nobody recommends and they do the job!...
I am just puzzled!...

Now let me tell you couple of things before you start firing at me.
When I was regapping the plugs, I did NOT touch (or come even close to) the tip of the spark plug. I just opened the end wire slightly with gapping tool I have(picture attached) And the amount I changed the gap was lot thinner than a thickness of a finger nail. So it is not that I opened it by a mm. The amount I changed the gap was so minimal I almost found it unnecessary to do this but I did it. Now I regret. I should have just installed them as they are.

I will try and get another tool to see if my tool is out of calibration. That is the only thing I could think of at the moment...

Do you guys have any idea what the heck happened here? How on earth the OEM plugs almost everybody's #1 is not working...

I attached many pictures for you...
 

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umm, from my side, my plugs are set to .054... my car runs great too. did u check to make sure that each corresponding wire is plugged into the correct plug on the coil pack which is then set up with the exact plug. in other words, u sure ur wires are going to the correct plugs?
 
I would guess that one of the Motorcraft plugs were bad out of the box. Doubt if a Zetec would idle with only 3 cylinders firing.
or
you didn't have a good fit on one of the plug wires. After removing, changing plugs back and re-installing wire boot you then got a good contact again.

Did you use dielectric grease on the wires?
 
Can you describe the "had to keep my foot on the gas" a little more? Did it run OK as long as you held the throttle open? Did it run rough no matter what but ran so bad that it would not idle? Did it have a miss in the roughness? That would be a sharp jerk each time a particular plug fired?

If there was a definite miss, then most likely there was one plug that was not firing and possibly one bad plug. As someone else suggested, are you sure the wires didn't get mixed. Crossed wires will cause at least two cylinders to not fire at the right time.

You may want to double check the part number for the spark plugs. I havn't worked on a Zetec in a long time, but I thought I remembered the heat range as 32, and your photo shows a 22. I also see some slight discoloration on the porcelain tip of the plug. That is extremely uncommon for a new plug, and perhaps an indication of too cold of a plug. Does the underhood sticker give the plug number (they used to).

I'm also still wondering if something else was wrong that since was corrected. Could there have been a vacuum line off that was restored when you changed the plugs back?

I know it is time consuming, but you could try changine the plugs back one at a time and starting the engine between each one to see if you can identify the offending plug or plugs.

That's about all I can think of without being there.
 
Big Jim is right, had to be bad plug or something else done wrong. Simply no reason for it not to run right. SOMETHING was not right. The difference between .050 and .054 gap is not a killer, the .050 gap will be .054 eventually with wear and it would run just fine like that. In fact I have seen old plugs over .060 that just didn't idle quite as smooth as should have but otherwise ran fine. I have also seen carbon string type wires run funky just by the way they were removed, then reinstalled to run right. That carbon string is some funky stuff. The end of string conductor can come loose from the metal insert, with luck the reinstall can jam the two back together again, but not usually. I messed mine up one night to where on reinstall motor missed like hell, after redoing one end of one that ohmed way out of shape resistance, motor went back to running what seemed to be perfectly correct, smooth idle, good power. However PCM picked up on it and went into limp mode with no OD. Changed wires out for new and instant reappearance of OD. Weird. Lesson learned, if standard carbon wire, don't mess with them anymore than necessary. Once zetec wires have been in place for awhile, the plug ends can be hard to remove without damage. I look at it now as if you must pull the wires and anything gets strange after the fact, change the wires! Of course this does not apply to metal core wire.
 
Thank you guys. I will do my best to address all of the comments...

First, I kinda have an OCD syndrom:) Please understand, I would be the last person on this planet to mess up the plug wiring order. Plus it is almost impossible to get it wrong when you are using OEM wires.
OEM wires are numbered clearly. They are cut at a certain length and they are clipsed with a plastic binder to fit the coil pack perfectly. I also have the OEM coil pack where all the cylinders are clearly numbered. Even if you wanted to mess up the wiring order, it would almost be impossible due to wire lenghts.
That's why I hate aftermarket plug wires and I never bought them. You can very easily confuse the right wiring order with an after market one.
I may use aftermarket plugs but I never even once used aftermarket plug wires on this car. So feel 100% cofident on this:)

Zorrex is right. Gap for Zetec is 0.050inches. But it is mentioned as mm on the underhood label. I took a picture of it and attaching it here. They did wrote the plug type on the label and it is not exactly the same but remember this is a 95 model car. So this label was placed there 14 years ago. Since then they may have slightly changed the plug label. Could you guys confirm that they sold me the correct plugs by looking at this label????

Silver Bullet, your "Bad plug theory" may explain this but this would be very very unlikely wouldn't it? Because the car was running like 3 cylinders were firing only. You may be right I don't know. I am pretty sure I did insert the boots properly onto each plug and yes I did use dielectric grease on both end of each wire. I always do that.

Jim, when I cranked the car it fired up immediately but it was like running on a 3 cylinder whether I gave gas or not. I gave gas and rpm went up but you would feel the obvious missing at every second of the run time. I was in disbelief and laughing at the same time. I pressed on the gas pedal one more time till almost half way and the engine was shaking so bad that I let go of it and when rpm came down to normal idle level the engine was about to stall. You could almost count the strokes and I shut it off. So it was that bad... I ran it total of 30 seconds and there was not even a single second that it felt smooth...
I can't tell the difference between a miss and roughness. My engine never felt smooth due to the worn engine mounts. So even if ignition is perfect, you will always get some roughness at idle or at driving. But this one was an obvious miss and it wasn't coming and going. It was always there.
After I shut off the car, I felt each of the boots and all felt tightly sat. So I didn't want to waste the day on this and immediately removed the OEM plugs and put the Bosch +4s back. The car came back to life. Thank God I said... At that point, this was all I wanted because I had lots if things to do throughout the day and I didn't want to get trapped home.
I didn't even touch any vacuum hose. If I had disconnected one of them unintentionally, it should still be disconnected as I write post.

Some suggested that it could be a bad plug out of the box and you also find it possible. Is there any way to test the plug?
You suggested a test but I am not sure if it will be accurate to run Motorcraft plug with Bosch ones. What are you saying here: like remove one of the bosch plugs and use all 4 OEM ones instead of Bosch one by one?
I really want to find out what happened but don't want to make things any worse. My car is running right now. It is not perfect but it is driveable. If the plugs are bad, all my loss is $16. No problem...

Does the picture I attached say anything?
 

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amc, you posted while I was answering other guys comment.
I agree a gap between 0.050 and 0.054 or even 0.045(the way they were out of the box) shouldn't make this much difference.
The only time I messed up the plugs was when I was at my friends garage years ago and I didn't know anything about spark plug gaps at the time. I cleaned the wires at his electric metal brush cleaner. I made each of the plug shiny again but they were no good anymore:laugh: Because I had shaved the tip of the spark element making the gap extremely large. The car ran like a crap(just like how it ran today) but even that was enough to get me to nearest Autopart store. It cost me $12 but the lesson was learned...
 
iskoos said:
Thank you guys. I will do my best to address all of the comments...

First, I kinda have an OCD syndrom:) Please understand, I would be the last person on this planet to mess up the plug wiring order. Plus it is almost impossible to get it wrong when you are using OEM wires.
OEM wires are numbered clearly. They are cut at a certain length and they are clipsed with a plastic binder to fit the coil pack perfectly. I also have the OEM coil pack where all the cylinders are clearly numbered. Even if you wanted to mess up the wiring order, it would almost be impossible due to wire lenghts.
That's why I hate aftermarket plug wires and I never bought them. You can very easily confuse the right wiring order with an after market one.
I may use aftermarket plugs but I never even once used aftermarket plug wires on this car. So feel 100% cofident on this:)

Zorrex is right. Gap for Zetec is 0.050inches. But it is mentioned as mm on the underhood label. I took a picture of it and attaching it here. They did wrote the plug type on the label and it is not exactly the same but remember this is a 95 model car. So this label was placed there 14 years ago. Since then they may have slightly changed the plug label. Could you guys confirm that they sold me the correct plugs by looking at this label????

Silver Bullet, your "Bad plug theory" may explain this but this would be very very unlikely wouldn't it? Because the car was running like 3 cylinders were firing only. You may be right I don't know. I am pretty sure I did insert the boots properly onto each plug and yes I did use dielectric grease on both end of each wire. I always do that.

Jim, when I cranked the car it fired up immediately but it was like running on a 3 cylinder whether I gave gas or not. I gave gas and rpm went up but you would feel the obvious missing at every second of the run time. I was in disbelief and laughing at the same time. I pressed on the gas pedal one more time till almost half way and the engine was shaking so bad that I let go of it and when rpm came down to normal idle level the engine was about to stall. You could almost count the strokes and I shut it off. So it was that bad... I ran it total of 30 seconds and there was not even a single second that it felt smooth...
I can't tell the difference between a miss and roughness. My engine never felt smooth due to the worn engine mounts. So even if ignition is perfect, you will always get some roughness at idle or at driving. But this one was an obvious miss and it wasn't coming and going. It was always there.
After I shut off the car, I felt each of the boots and all felt tightly sat. So I didn't want to waste the day on this and immediately removed the OEM plugs and put the Bosch +4s back. The car came back to life. Thank God I said... At that point, this was all I wanted because I had lots if things to do throughout the day and I didn't want to get trapped home.
I didn't even touch any vacuum hose. If I had disconnected one of them unintentionally, it should still be disconnected as I write post.

Some suggested that it could be a bad plug out of the box and you also find it possible. Is there any way to test the plug?
You suggested a test but I am not sure if it will be accurate to run Motorcraft plug with Bosch ones. What are you saying here: like remove one of the bosch plugs and use all 4 OEM ones instead of Bosch one by one?
I really want to find out what happened but don't want to make things any worse. My car is running right now. It is not perfect but it is driveable. If the plugs are bad, all my loss is $16. No problem...

Does the picture I attached say anything?
Click to expand...

According to the underhood tag, the heat range is correct. They are both 22. The PP on the end of the number on the underhood tag is for double platinum. They have been replaced with fine wire platinum / iridium. On the V6 that happened with the 96 model and probably the same for the 4 cylinder. What you bought is probably the better design.

Your description is of a dead miss in one cylinder. Most likely one plug. Substituting them one at a time is one way to pin down which plug is bad. Another would be to have an assistant keep the engine running while you pull up one plug wire at a time until you find the cylinder that doesn't change and that will be where the bad plug resides. You won't hurt the engine by testing this way or from running the engine with two different types of plugs as long as you don't do it for too long. Get the testing done within five minutes or so of running, and don't drive with mixed plugs for more than a few days.

One more thing that I can think of is that it is easy to accidentally jam the spark plug boot down between the side of the plug well and the spark plug without realizing you missed the plug. It sounds like you have eliminated this possibility, but I have had it happen to me.

Something else occurred to me to check for as well. Depending on the tools you used to change the plugs, it is possible that you cracked the porcelain on the outer part of the plug. It may not be obvious unless you know to look for it. You have them out now, so look for any evidence of damage to the part that sticks out of the engine.

If it is a bad plug and you didn't damage it there should be no hassle exchanging it.
 
Make sure the sp wires are in the correct order.
Zetec I-4 Spark Plug Wiringorder

Firewall
Engine 1 2 3 4 ..... Coil 1 3
Radiator ............... ....4 2

Spark Plug gap 0.050 inch
 
has the car always been like that?

It sounds more like you have a timing issue then anything else, is your CEL on? What about the coil pack have you changed it out for a different one?
 
I would say swap wires with another cylinder. I highly doubt its a plug problem.

You might have pulled on the crimped part inside the wire boot itself. So it's getting very little contact while the vehicle is running causing this very problem.
 
I had a similar issue with my pre98, turned out to be the coil pack, with certain spark plugs it would only run on 3 cylinders.

get a new coil pack and use it as a troubleshooting piece.
 
agree with above post, put oem plugs back in and see how it runs, if it runs bad replace one plug at a time with your old plugs as process of elimination. while a bad new plug is not common, it happens everyday and to all kinds and makes of plugs as well as other parts. plus it sounds like you got these online from another ford dealer, if so they were shipped again and sometimes ups is not always super careful with the handling of stuff. but i had a hesitation on takeoff with autolite plugs that was cured with motorcraft plugs, and before the wolves come out, the autolites were in it when i bought it! lol good luck
 
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