mysterious misfire
#1
mysterious misfire
1995 Oldsmobile 3.4 l V-6 Mysterious misfire. Started intermittent. new plugs, wires coil pack, camshaft positioning sensor, now no codes or check engine light but runs on 5 cylinders and four when on the highway unless I back of on accelerator. Number 1 cylinder has no spark but coil pack seem ok Lost for options to try
tim
tim
#2
It's entirely possible some of your new parts may be faulty.
First job is to trace back to why you have no spark at #1. Substitute the plug, then the wire, then the coil pack, unless the coil pack has a faulty supply it can only be one of these three. Do it one at a time or you won't know which is the faulty item.
Before you start taking things off, if you can lift the hood and run the engine in the dark, this will show up any tracking, that is arcing between the coils and the plugs. if you see this phenomenon you will save yourself some work because you will have identified the fault.
Welcome to CO btw.
Roger.
First job is to trace back to why you have no spark at #1. Substitute the plug, then the wire, then the coil pack, unless the coil pack has a faulty supply it can only be one of these three. Do it one at a time or you won't know which is the faulty item.
Before you start taking things off, if you can lift the hood and run the engine in the dark, this will show up any tracking, that is arcing between the coils and the plugs. if you see this phenomenon you will save yourself some work because you will have identified the fault.
Welcome to CO btw.
Roger.
#3
Here is a pretty good article on diagnosing this type of ign. Sys.
http://easyautodiagnostics.com/gm/3....l-pack-tests-1
http://easyautodiagnostics.com/gm/3....l-pack-tests-1
#4
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
No power to the #1 plug would suggest a fault,with the coil pac you replaced. Put the old one back on and see if that changes the situation. Replacing everything all at once makes diagnosis harder to do.
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