Quote Originally Posted by avguy View Post
Were you able to check for spark on the other plugs? If all of them have spark, and with fuel being ok, then it's surprising it doesn't fire at least a bit each time you try to start it. So if you've confirmed spark, then definitely do the compression test. For that one you'll want to pull the fuel pump relay and all 4 plugs. Then keeping the gas pedal down to the floor while cranking, check each cylinder dry (without squirting any oil into them}. You should see compression numbers somewhere in the 190-205 range. Slight lower compression might be ok, but not too much lower.

Good spark basically confirms that the crank sensor is good (not for certain but nearly so), so IMO it would be a waste of time and money to hang one of those on. And a bad cam sensor should still allow it to start and run - sputtering perhaps, but at least something.
I was limited on time yesterday, so I didn't check the other 3, but I will out of due diligence. I'm 98% certain they're all sparking though, since every time we have gotten it to turn on, it ran smoothly with no misfires, and I've had scenarios where I've had plugs not work but the engine was still able to fire. Nonetheless, I will look into an inline spark tester like xintersecty mentioned.

I'm about to head to the store in a few and grab a compression testing kit, it should be back by now I'd imagine. I hope it checks out, or else she's going to have some bigger issues to face, though I have a feeling it will do okay, especially as this was a reoccuring problem for awhile that continually got worse. If it was a piston ring, I would think the problem would have been immediate and not progressed more over time. Same with the valves/valve seat, but I could be wrong.

And damn, if you're right about the sensors, then I may need to find a compatible used ECM that I can swap to test to see if that helps at all, because at that point I'm nearly stumped.

Quote Originally Posted by xintersecty View Post
This is the list of troubles I had with my 06 over the years
1) Oil leakage from the valve cover into the spark plug holes
2) Check timing. Is the timing belt in good shape and does the marks line when the Cylinder #1 is TDC?
3) A Good solid energy source (electric). Is the battery in good shape? Are the ground wires connected properly? The 06 you can put a spark tester inline with the plugs.
Preach it on number 1 haha!!

I haven't checked the timing belt entirely yet, but I was able to see the belt when I had the valve cover off and had her crank it for ~20 seconds or so. Belt stayed taut and unbroken, though I haven't seen if it became misaligned. I can't see how that would happen, but my cars all have timing chains, so timing belts aren't something I've screwed with much. Even if the belt was off, wouldn't the car be running like crap every time we've managed to get it to start?

My instinct is telling me this is an energy delivery problem. The problem is the battery is brand new, and was swapped again for another brand new battery and still no go. New starter as well. I've been able to get the car to sometimes turn on by having my battery connected to hers and jumping it while she cranks for a very long while, and that's the only way so far. I feel like somehow enough energy is not being transferred from the battery to the starter to get it to fire like it should, but as far as how to test for that, how plausible that is, or how that could have even happened, I'm stumped.


Will report back soon with compression and spark results!