engine sputtering and rough idle

94scnflt

Registered User
Ok, I changed out my spark plugs last week and the engine started to idle really rough and when I attempted to drive it I could hear the engine sputtering, I guess it sounded like it was missing but there is no hesitation or bucking. I used AWSF 34PP spark plugs gapped to .054. I ordered new wires thinking that might cause it and I just got done replacing those. The idle is not as rough, but it still sputters really bad. I pulled one wire off at a time and that test was fine so I know the plugs and wires are good. What the hell is the problem? Could the gap on the plugs do it? Is the dis module bad? I need help!!!!! My only option know is to take it to ford and spend $100 dollars and hopefully they can tell me what is wrong. :mad:
 
If this happend right after a plug change you might have bad wires or a cracked plug. always use dialetic grease on the rubber boots both plug and coil.
 
scbird1

That is the way I have my wires, I double checked today. The haynes book I have has the same thing. I knew it wouldn't be that easy. :mad: :mad: :mad:
 
I had a problem a while back with lexy [my lx] went to pep boys
to buy new plugs. gaped them all ran like crap for a week till I took the plugs back out to find that one was not the same # but all the # on the boxes were the same. Im sure your plugs are back in and if your arms look like mine right now im sure you dont want to pull them out again. just a thought. Check out this pistion
never try to run a blower on a n/a 3.8 this guy did
 

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scbird1

Yeah, my arms are tore up. Good news is I can change plugs in 30 minutes now. Anyway, I checked each plug before I put them in and they are all correct. Besides, if I put the old ones in it does the same thing.
Do you think there is a hard fault code in the EEC that is not clearing, somthing to do with the ignition. It's a long shot I would say. I disconnect the battery each time I work on the car, I was told that would clear any faults. I guess I will have to shell out the money to take it to ford. One last thing, can the gap of the plugs screw up performance if they are not all the same, or a little off. I checked them all before putting them in but I might have bannged one.

P.S. What is n/a, naturally asperated?
 
Oh ya these plugs fire 2 at a time and they must be perfectly matched or one will get more spark then the other. I was experimenting last night with 2 plugs grounded, one with a larger gap and most of the spark went to the smaller gaped plug. have you tried driving the car and doing the computer relearn? some times these problems go away. Its hard to mess up the gap unless you realy drop it on the electrode.
 
scbird1??

How do I drive and do the computer relearn?? I am taking it to get a diagnostic done on the car, hopefully that will help.
 
wires could be it....

I've gone through this a 100 times...

You think you have good wires....good connections....and somethings not right....
the car is intermittent...misses...etc....

Change each wire individually with a wire you know is good... and maybe you'll luck out on that....
 
I took it yesterday and had a diagnostic ran on the car. The only codes it spit out were 172 and 136 for running lean. The other thing we noticed is the TPS at idle is .80V when it should be .50V. I went home and dropped from a 85mm TB and 76mm MAF back down to a 70mm TB and stock MAF, with no change. I pulled the plugs and put in the originals again, with no change, I put the new plugs back in and started swapping wires, again, no change. I really don't think the plugs and wires are bad becuause no matter what combo I use the car runs the same. The car is hesitating and bucking. Could the coil pack be bad? Who knows, any help would be great.
 
d

Just curious, but your using Premium gas right? And also might want to change your fuel filter, that could cause symptoms you describe. Good luck

Kyle
 
fuel filter is brand new. I am running 91 octane out here is california and I put some octane booster in it to help with the detonation.
 
I'm having a very similar problem. Here's the thread:

http://forums.tccoa.com/showthread....&threadid=13158

It's Splitportbird's thread, but I posted my problem in there. I'm pretty sure mine is fuel related as well. I pulled the tank to find dirt and junk in there, and water in the fuel filter from condensation. Just goes to show that you shouldn't run your tank extremely low.
 
This might be a long shot, but did you disconnect any of the super charger inlet lines, if you did make sure they are all secure. I had the same problem when I put my car back together. I wound up taking the whole ignition system back off and checking everything at work. Then when I put it all back on, it started running just fine. One thing I did find wrong was there is a single wire that connects to another plug under neath the fuel rail on the passenger side on the right side of the oil filler. Make sure that its not grounding out on anything. The spark plug wires have to run right over top of this wire.

Hope this helps.
 
she's fixed!!!

Ok, took her to the dealership today. I paced back and forth like a parent waiting for there kid to come out of surgery. The result of my whole hair pulling ordeal, ONE BAD BRAND NEW PLUG!! I guess one of the old ones was bad to, that's why I wasn't seeing any results swapping back and forth. Oh well, she's fixed and running good. Tomorrow, the 85mm TB goes back on along with the 76mm MAF and the 89-93 sc pulley to get rid of the detonation. I am so happy, drove her around a little tonight, but will drive her more tomorrow. It has been 2 long weeks but I've got my baby back. Thank you all for the help, I am so thankful for this website. :D :D :D :D
 
My plugs were changed at 69K in the '89 SC. I experienced similar symptoms. Believe it or not, one of the NEW plug wires was bad.
 
Out of curiosity, were these OEM plugs or another brand? No particular point, just curious. Anything man-made can be made wrong.
 
Ya and I love changing plugs as much as the next guy but I check every plug for cracks as well as the numbers. All it takes is for someone at the parts store to drop one or put the wrong plug in the right box. Dont forget the dialetic grease around the boots.
My arms are still bruised from my ordeal. Glad to hear she all fixed and running again.
 
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the new plugs were ford OEM motorcraft AWSF 34PP double platnum plugs. I checked all the numbers and they were right, I must have just got a bad one.
Now about the grease, I didn't put any on and I don't think the dealership did when they looked at it. I am afraid to pull the wires off, it runs great, probably after that it won't. Thanks for all the help.
 
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