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Discussion Starter · #1 ·
I have had a slight misfire for a while now and I have changed spark plugs and it was still the same now after putting Magnecors on it seems to be worse. Any ideas, and what can I try next to pinpoint the misfire. I am really getting a little down about this now.
New post cat lambda sensor going on tomorrow as that came up on two separate occasions on my code reader.
Here's some pics,



 

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Discussion Starter · #4 ·
Changed the coils, plugs, post cat lambda.
The misfire now seems even worse after the new lambda sensor has been put on, but the cat is pretty much on the way out so don't know if this would cause any rough running?
Can somebody please put up a checklist of things I need to check to find this elusive misfire and I will work my way through them when I am next off cos I am getting to the point of no return. Also in my picture of the magnecor leads, can somebody tell me if they look like they are in/set up right. I did pull each old lead out in turn and replace accordingly but I am just double checking.

Please help me folks
 

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Some info I found. Might help

Is it a steady misfire? When does it misfire?
In the case of a steady misfire, isolating the misfiring cylinder is the first step in diagnosing the problem. The old-fashioned method for finding a weak cylinder is to temporarily disconnect each of the spark plug wires, one at a time, while the engine is idling. When there's no change in the idle speed, then you have pinpointed the weak cylinder.
If you find a weak cylinder , here are a few things to check. Have you got a spark? The easiest way of course is remove the plug and crank the engine to see if it sparks.

Then confirm the fuel supply, when you take the plug out check to see if its wet and smells of fuel. Not the most accurate way of telling but gives a basic indication, even if wet could still have a propblem.

The next quickest thing to do is do a compression test .. if you have low or no compression on that cylinder, you will have a misfire. Likely a burnt valve or valve seat...

Also very carefully check the wires that go from the coil pack to the ECU. They have been known to chafe and short where they pass along the cam cover. Also check the wires that go into the big electrical connector under the throttle body, again, a known chafing point.

It's also said that a failed coil could spike the ECU (don't know if you had any probs with your coil pack before you changed it), but that was repairable dependant upon how much it had been juiced.

Rusty

Hope some of that helps
 

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Discussion Starter · #6 ·
Cheers mate, that's definitely a few things to check up on and see if that narrows it down. I bloody hope it isn't a valve or valve seat tho :agh:
 
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