Dead cylinder
Dec 9, 2011 | 06:32 AM
#11
No, it will spark regardless. Just re-read your post about not seeing anything on the light, sorry I missed it.
What I would do is check all the wires. You will need a multimeter to ohm-out the wires at the coil connector. I'm talking about the 4-pin connector that plugs into the individual coil, not the large 7-pin one. It will be pink, blue, brown, and black. Pink is IGN, blue is control, brown is low reference and black is ground. Black is easy to test, pink will need to be checked at a fuse in the fuse box, blue and brown are checked at the PCM connection. Pin location would depend on what truck you have. I had to track down a nasty misfire issue myself a few months ago...had to do all this stuff
What are the details on the vehicle, in case I missed it?
What I would do is check all the wires. You will need a multimeter to ohm-out the wires at the coil connector. I'm talking about the 4-pin connector that plugs into the individual coil, not the large 7-pin one. It will be pink, blue, brown, and black. Pink is IGN, blue is control, brown is low reference and black is ground. Black is easy to test, pink will need to be checked at a fuse in the fuse box, blue and brown are checked at the PCM connection. Pin location would depend on what truck you have. I had to track down a nasty misfire issue myself a few months ago...had to do all this stuff
What are the details on the vehicle, in case I missed it?
Dec 9, 2011 | 06:57 AM
#13
Where did you test pink at? It is important that you check from the coil connector itself. And I'm not talking about voltage, simply continuity. You should see less than 10 ohms with a good connection. More than likely it will be less than 1. Testing continuity for ground would be as easy as connecting your leads to the black wire on the connector and the alternator. A bad fuse may cause problems with multiple cylinders, but a good fuse does not mean a good wire to the connector at the coil.
Dec 9, 2011 | 07:09 AM
#15
You would need a pretty badass multimeter, it would need an oscilloscope. It would give you a 5Hz square wave with a 600rpm idle. If your idle is smooth enough and you draw out the scale, you might be able to catch a problem just by looking at the scope.