Calling Dr House: Ignition miracle needed

[badjuju]

Here we go:
Straight six, wasted spark on a 7mgte, 6+2 config on Vems, problem happens with firmware 1.0.73, and firmware 1.1.70.
I foul my plugs in about 10 min of running, due to running pig rich.  Plugs 2 and 5 are never discolored, simply covered in fuel.  Plugs 1,3,4, and 6, are so fouled you could paint with them.
Injectors are getting signal, my LED fires right up when cranking.
Coil packs are getting signal, my LED fires right up when cranking.
Spark plugs are firing, I get spark from all 6 plug wires.
I thought maybe the coil handling 2 and 5 was only firing intermittently or something, so I replaced it (I have 6 spares ).  Did not help.
I thought maybe I had connected my coil to a logic driver instead of a big boy driver.  My rational behind this was that just because I get a spark, doesn't mean it's intense enough.  I pulled wires 5 and 6 to compare their spark intensity (seemed the right thing to do), and they seem to be equal with any other spark from a running motor.
I noticed today that plugs 2 and 5, when I pulled them, had a little black, as if they were firing, but there was no soot.

WTF is going on?  Bent valves maybe?  It seems like the most logical choice to me so far.

[[email protected]]

Are 2&5 grouped in your wasted spark setup?
We had something similar on a Skyline RB25 engine, so we went to wasted spark (which we were going to do anyway), and the problem persisted, then we found that two injectors weren't actually delivering fuel.
So it might be worth swapping your injector plugs: 2->3 and 5->6 and see if the issue follows you around.

[badjuju]

Good idea.  I'll certainly try it before I pull the head to check for bent valves.

1-6, 2-5, and 3-4 are grouped together.  The injector plugs are firing when I check, however, and the plugs are covered in fuel when I pull them.  Is it possible that vems isn't firing them every time it's supposed to?

[[email protected]]

I guess that it is possible - but do you should be able to do a compression/leak down test before you pull a head.
You should be able to see with a timing light where the crank is positioned on 2&5 ignition events.  I put a stripe down the front of the pulley so I can see number 1's position across all cylinder events.

[badjuju]

Before I purchased the motor, I tested the compression.  After installing a cometic mls gasket and reinstalling the arp studs the previous owner messed up, and forgetting to tighten the timing belt tensioner, and cranking the engine for a while, and realizing what I had done, and setting the timing correctly and tightening the damn tensioner, I got it to start and run and all that, then noticed the spark plug issue, see post #1.  Anyhow, I thought I'd run the compression test again, hoping to find that 2 and 4 were extremely low, thus telling me what my problem was.  Anyhow, here are my numbers... 2 and 4 are lower than the rest, but I'm not experienced enough to know if they're low enough to justify calling the valves bent or not seating.  tell me what you think:

Pre Purchase: 135 133 137 148 125 155
Just now:     151 143 151 160 145 155

[badjuju]

allllllso... I just ran an LED to each coil pack, and it seems to be firing left middle right, rather than left right middle, which is what I, and VEMS were under the impression it was firing.

Super duper.  I'm thinking maybe cyl 2 and 5 are a little lower than the rest, not because the valves aren't sitting, but rather because I'm washing the piston rings with fuel.

Thoughts?

[Dylan@AM Racing]

We work on a 10% variance between the highest and the lowest cylinder. Looks like you're ok. You can unplug injectors, put some oil in the cylinders and do a wet test.
Check your injector spay pattern as well. fuel could not be atomizing properly.