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Running on 3 cylinders???


gyro33
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Any ideas would be appreciated...

 

Started the car... rough idle... won't come out of it... like chug chug... regardless... secondary kicks in... not really a difference... at speed of 70 I thought it smoothed out... but during acceleration same pattern... chug chug... smooths out a little at higher RPMs but not really... makes no difference if hot or cold...

 

Lost in the corn fields of Illinois... Thanks for any ideas...

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you need to find which cyl is not firing and or has a problem.

 

run it, and pull the spark plug wires one by one with a spark plug boot puller. Whichever cyl DOES not react, when you pull the wire, that is the cyl that is not firing. Only pull the wire for a few seconds at time.

 

For instance. With the car running, i take my wire pullers and pull cyl 1 wire. The engine starts to miss even worse ( in fact it will barely run). Cyl 1 is firing. i go to cyl 2 and pull the wire and nothing changes. I plug the wire on again, nothing happens, pull it again, nothing happens. This is the cyl that is not firing. If cyl 2 it was firing, it would have made the miss even worse like cy 1.

 

 

Sometimes it takes a little practice, especially if it is only a slight miss . You have to carefully watch the engine to see what it does when you pull the wire.

 

Once you have found the problem cyl, then remove the spark plug on that cyl and check that first. Make sure the plug is gapped correctly, that the center electrode hasnt failed, that its not fouled or caked with oil deposits etc.

 

also, make sure the plug wire is ok. When you are pulling the wire checking for a miss, hold the wire slightly off the plug, you should hear a tack tack tack of the electricity as it arcs from the plug wire to the plug. Then you know you are getting spark to that cyl. Remember, only do it for short periods of time.

 

 

 

If the plug checks out, then the next step would be to do a compression check, then if you find low compression on cyl, a leak down test.

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mine burned a plug wire and was running on 3cyl...sounded like a big block with a lopey cam...lol

 

didnt run like one though. But, other than plugs and wires...not much else could cause it litterally running on three. Unless its loading up really bad, it would make it sound like it.

Edited by strang3majik
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new and good are not ness the same thing

i've ran into a lot of bad NEW plugs

 

one thing that happens to new plugs is the center shield breaks and slides down covering up the tip , when holding them with tip up you may not see it ,

hold the plug tip down and lightly tap the end on some thing to see if the center moves

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