[rdubb17]

Went to mess around with the engine again to try to get it through emissions and experienced a no start event.

Started engine for about 2 minutes, enough time to grab the previous tune to manipulate it. Changed the base timing table (retarded to 14 deg). Re-uploaded the tune and then aprox 10 seconds after loading the tune, the engine just died. Loaded the previous tune back in, engine still would not start. Grabbed a tune that was saved and known working a month ago and still would not start.

Diagnostics so far:
- confirmed fuel injectors are firing during crank
- confirmed fuel pressure was available at fuel rail (~39 psi)
- confirmed spark available at spark plug (very weak)
- confirmed spark available at coil (stronger but still orange in color)

Pulled the coil (MSD P/N 8227) and measured primary and secondary resistance:
- Primary = 0.7 ohm
- Secondary = 3285 ohm

Specs on this coil calls for:
Primary resistance .68 OHMs
Secondary resistance 4.8K OHMs

Do you guys think it may be a coil problem? How likely do they just completely fail instantaneously? I don't believe it's a EEC or Moates problem, fuel pump is cycling normally, injectors are firing, I can write and then read back what I wrote from the memory.

I'm also weary if the TFI or PIPs went out. I may have to investigate this too...

[cgrey8]

I've had scenarios where I would write a tune while the ignition was on/engine running and something about the write goes awry causing the engine to either run horribly or the engine just dies. Most of the time this has happened to me, the engine was getting WAY too much fuel. I could even datalog LAMBSEs in the .5s and the WB pegged rich!!! What I found fixes this is cycling the ignition to force the EEC to "reboot." It may take a bit to recrank after being flooded, but this usually corrected the misbehaving EEC.

As for TFI malfunctions, it should fire regardless of whether the EEC is functioning or not. During crank, the TFI always commands whatever advance the distributor is set to (i.e. base-advance set with SPOUT jumper pulled). So if you don't have spark at all, that's not likely to be the EEC's fault. That's going to be ignition system...TFI, coil, distributor pickup sensor, or aftermarket ignition box (if installed). You can eliminate plugs, plug wires, cap, and rotor just by testing if the coil wire sparks to ground. And given the ignition box is the most likely culprit, bypass it and see if you get spark.

If you have spark, then the next thing to confirm is fuel. Check fuel pressure. If you got pressure, that eliminates the FPR and pump.

[rdubb17]

It did seem as if the injectors were pulsing quite a lot during start, although I didn't confirm this with a test light. I don't exactly know the PW commanded at the moment (need to record data).
I did confirm that there is fuel pressure during crank at the fuel rail (39PSI or so)
I confirmed that there is spark at the plug (seemed weak but present none the less)

Think the secondary winding is the culprit? The readings were below MSD's and the spark is weak. Hate to buy another but it looks like I'm probably going to have to try.

The odd thing I noticed was, when I released the key from the start position (engine crank) to the engine run position, the engine would actually sputter a few times and then die. This didn't happen every time, but it did quite a few.

[rdubb17]

I just wanted to update this posting.

Coil failed (MSD 8227). Replaced it and she fired right up.