Trouble getting spark to rear trailing plug

[Neo-Vader III]

My FC's been sitting for the winter (as normaly, I don't drive it when there's Snow/ice/salt on the road) and the battery was old, so I charged it up to do my usual warmer weather start ritual, as it had only been sitting for less than three months, I did all the normal things to try and start it. It failed to turn over good enough to catch, and then the battery died. No prob...bought a new battery and did the usual oil in the plug holes to make sure there was compression and tried again. Nothing. It would turn over, but not start.

So after doing some diagnostics such as checking to see if the plugs were getting spark , I noticed that all but the rear trailing one was. So I swapped wires, changed coils with some spares I had, even changed the housing the trailing coils sit on in case the wiring had gone bad in them and still nothing. Every plug will light except the rear trailing and it won't fire up without it.

I'm tearing my hair out trying to figure this one out, but I'm at the end of my options. As towing it to a garage and spending way too much is not an option right now, I thought I'd turn here and see if anyone's got any suggestions. I'm open to any ideas and I'll let you know if I've tried it already. If not, I'd be happy to give it a go. As long as it doesn't involve something outrageous and out of my comfort zone ^_^ (I don't have a nice heated and large two car garage, and must do most of my work outside unless I move a lot fo crap out of the garage like the Bikes)

Anyone...help? Anything's appreciated right now.

[tweiss3]

I'm not sure what to tell you, except check the input connections to the trailing coil in question. Did one of the wires in the connector back out?

[Neo-Vader III]

Nope, checked and had to dis and re-connect both of the terminals leading to the coils beneath the mount when I changed it to see if it was bad. Both seem to be contacting well, and I even sprayed in there with electrical contact cleaner before re-assembling to be sure. The only thing I can think of now is it must be something leading up to those points, but that's all in the wiring harness.....I'm praying something isn't bad in there.

[tweiss3]

That may be the only thing left to check. The last thing before going that route would be to make sure the connector to the ECU is fully plugged in and didn't for some reason back out. Also check fuses, cause you never know.

I do feel you on doing the work outside, I had to replace the oil cooler lines while it was below zero, outside in the snow.

[RETed]

If you lost power or disconnecting electrical plugs, there's a 50 / 50 chance it'll kill the trailings.
Easy indication of this is your tach will not move (when cranking).

How did you check the trailing spark?
Did you eliminate the spark plugs?
Easy test is to shove a small screwdriver into the spark plug end of the wire and put it close to a known, good ground spot - does that spark when you crank?
If you're trying to test with the spark plugs, it's a good chance your spark plugs are "dead".
You mention putting oil in the engine - the oil can kill the spark plugs.
Dead spark plugs will not fire.


-Ted

[Neo-Vader III]

Figured it out. I did all the proper tests to eliminate the spark plugs, wires and such, put a multi-meter on the coils and found out they were still good. So as a last ditch I took apart all the connections from the crank angle sensor to the coils themselves and cleaned them out with connector cleaner, then sprayed out the crank angle sensor itself. It fired right up after that. Must have been some buildup of gunk or a bad connection in there somewhere. Thanks for all the help/suggestions.

Rob

[Ender]

yikes, yet another little thing to watch out for. dirty contacts are such a pain!