Changed plugs and now running like CRAP
Thread Starter
Race Director
Joined: Apr 2007
Posts: 14,062
Likes: 602
From: Henderson Nv-Rohnert Park/Sonoma C o. ca/born in NY Rockaway Beach.
Changed plugs and now running like CRAP
OK so I just did a tune up, new oil, filter,air filter,and now its running like its on 7 cyl...... WTF.....I checked all the wires to make sure they are on all the way ? ?
Could my timing be that off ? what am i missing ?
Could my timing be that off ? what am i missing ?
Thread Starter
Race Director
Joined: Apr 2007
Posts: 14,062
Likes: 602
From: Henderson Nv-Rohnert Park/Sonoma C o. ca/born in NY Rockaway Beach.
I did one plug at a time.. so I dont think I could mix wires, I checked the gap on them all..car has been running fine till now....BANG HEAD.....
Team Owner
Joined: Feb 2003
Posts: 54,135
Likes: 9,447
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
the boot may be over the plug but that doesn't mean its clipped into the plug. do you have a IR gun. if so while the car is running check each exhaust port. that will be a quick way to tell what one it is
Pro
Joined: Sep 2010
Posts: 745
Likes: 66
From: Hutto Texas
Look at your car in the dark with the engine running. I experienced the same thing on an old Chevy truck several years ago. I tried everything and it was not until I was looking at it early in the morning before the sun came up that I saw the new plugs were arcing to the exhaust manifold. Turned out I had 2 plugs with cracks in the white ceramic. I pulled them out and put in 2 plugs from my Camaro at the time and it purred like a cat.
Go ahead and double check your plug wires again to ensure they are in their correct position on the distributor. Also, make sure the wires are firmly secured to the spark plugs. If they are not pushed on all the way they will not work.
Go ahead and double check your plug wires again to ensure they are in their correct position on the distributor. Also, make sure the wires are firmly secured to the spark plugs. If they are not pushed on all the way they will not work.
Race Director
Joined: May 2003
Posts: 10,956
Likes: 409
From: California
Hey buddy..... Got to get ready for the 28th!!!!!! Had this happen to me on the on the jeep.... Bad msd plug wire.... Ohmed out ok on the meter, but when I did a plug wire pull while engine running, I found the wire bad..... Replaced it and all ok..... It was a factory crimp that was bad
Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
Same thing happened to me. If you search i am sure we can find my similarly titled thread. 
In my case it was a bad spark plug wire. Of course, your experience may vary. In fact, I think the metal contact piece actually fell out of one of the boots, so the spark plug wire went on fine but there was no metal to metal contact. doh! 
previous issues following tuneup: Car wouldn't start at all! One time it was bad points right out of the box. Another time, removal of the new distributor cap revealed.... missing rotor!
ah! so many ways to screw it up!!!
In my case it was a bad spark plug wire. Of course, your experience may vary. In fact, I think the metal contact piece actually fell out of one of the boots, so the spark plug wire went on fine but there was no metal to metal contact. doh! previous issues following tuneup: Car wouldn't start at all! One time it was bad points right out of the box. Another time, removal of the new distributor cap revealed.... missing rotor!
ah! so many ways to screw it up!!!
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Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
you can try pulling off the ignition wires one at a time and see if pulling one DOESN"T make any difference and you found which cylinder is the issue, than you only have to search a bit more to find out if it's a bad plug, a bad ignition wire, or bad contact on the distributor cap, etc
I had done a similar tjhing a few years back on my '65 and shotgun changed out all the wires, plugs, new dist. cap and rotor, etc.
Had car only running on 7 cylinders so had to go thru th whole process to find where the problem was. turned out to be TWO bad ignition wires from the brand new set I had just bought and installed.
Now i tend to just try to change out one part at a time to avoid the same type of disaster and nightmare of diagnosis
I had done a similar tjhing a few years back on my '65 and shotgun changed out all the wires, plugs, new dist. cap and rotor, etc.
Had car only running on 7 cylinders so had to go thru th whole process to find where the problem was. turned out to be TWO bad ignition wires from the brand new set I had just bought and installed.
Now i tend to just try to change out one part at a time to avoid the same type of disaster and nightmare of diagnosis
Le Mans Master
Joined: Jun 2007
Posts: 7,666
Likes: 1
From: Where it's always hot as Hell-South Louisiana.
St. Jude Donor '07-'08-'09-'10-'11-'12-'13
one of your "new" plugs is bad.
While the car is running,pull each spark plug wire off, one at a time, to find out which one is NOT making a difference. (you can do this at the distributor top to make it easy)
That would be the one thats faulty. wire, plug, fitting,etc.
While the car is running,pull each spark plug wire off, one at a time, to find out which one is NOT making a difference. (you can do this at the distributor top to make it easy)
That would be the one thats faulty. wire, plug, fitting,etc.
Thread Starter
Race Director
Joined: Apr 2007
Posts: 14,062
Likes: 602
From: Henderson Nv-Rohnert Park/Sonoma C o. ca/born in NY Rockaway Beach.
Just ran it in the garage and sonds good.. we have rain now for a few days but as soon as it clears ill take it out....
Melting Slicks
Joined: Jun 2006
Posts: 2,071
Likes: 147
From: S Nevada
Look at your car in the dark with the engine running. I experienced the same thing on an old Chevy truck several years ago. I tried everything and it was not until I was looking at it early in the morning before the sun came up that I saw the new plugs were arcing to the exhaust manifold. Turned out I had 2 plugs with cracks in the white ceramic. I pulled them out and put in 2 plugs from my Camaro at the time and it purred like a cat.
Go ahead and double check your plug wires again to ensure they are in their correct position on the distributor. Also, make sure the wires are firmly secured to the spark plugs. If they are not pushed on all the way they will not work.
Go ahead and double check your plug wires again to ensure they are in their correct position on the distributor. Also, make sure the wires are firmly secured to the spark plugs. If they are not pushed on all the way they will not work.
