No Spark to the plugs.. "scratching head"

[washingtonracer]

Alright first with the specs
SBC 406 TT
FAST B2B WB
MSD Digital 6
MSD Pro Billet Dist
About a week ago I finally finished getting everything put together and attempted to turn it over. Not expecting it to start, but what do you know, it fired right up first try. Sounded beyond what I had ever hoped for. But.... the timing was off. So I went back over the basics. (This is my first time with this ecu). I re set up the timing. 50 deg on engine and 50 in ecu. then turn motor to 28degs. I realize (duh) I cannot phase my distributor. But it still ran. So anyways I installed a crank pickup and locked out the distributor. Now it won't start at all. I hooked a timing light to all spark plug wire, and I am getting no light. I am however getting spark from the coil wire to the dist. I have no clue what can cause this. the timing is setup still at the same specs as before and the dist is phased to 28 degs at num 1. regardless of that I would still expect the timing light to fire off even if the timing was not on. Could it possibly be my battery? I have worn it down, and have resorted to running a charger while doing this. The motor turns over just fine so I assume that there is enough charge to light the dist. My only other thought is perhaps when locking out the dist, removing the weights some how lowered the rotor height and now there is too large of a gap for the spark to jump to the spark plug. I know the ecu is receiving a good signal cause both the digial 6 is showing and the timing light when on the coil wire responds.

Any ideas, cause I am really scratching my head on this one.

 

[TurboTR]

Yes, it sounds like you just don't have the system phased right. You need a few things to be right here for it to work.

1) The rotor phasing. One way to get that right is to set the engine to about 28 deg BTDC or so. Then line up the center of your rotor lug with the center of your number 1 cap post. Joila.

2a) To work correctly, the FAST system needs the crank reference pulses to fall within a certain range of crank angle deg (CAD). If you have a the "generic" b2b system, it will want those pulses to occur around 50-70 deg BTDC for each cyl. You must verify this. Figure out where the pulses are occuring- use your eyeballs at least to see where in CAD the ref pulses will occur by lining up your sensor with the pickup unit. Assuming you have a mag pickup (either on the crank or in the distrib), the magic pulse happens when the center of the pickup and the center of the sensor are directly aligned If the pulses are outside the target range for your ecu, modify your crank sensor system until it is inside the target range. This will get you close enough to start. If you have other than a generic ecu, like say you are trying to use a TFI system for example, then the target range is different than 50-70 deg BTDC in that case.

Then 2b), set the initial crank reference angle variable in the FAST setup/config section to whatever number you deteremine from 2a) above. This simply tells the FAST system where the crank ref pusles are occuring, so that it can then line up the timing pulses with the actual crank position.

3) To fine tune 2b), set the spark timing to a known, safe value for low speeds/idle- say like 10 deg BTDC. Start the engine and use your timing light to fine tune the setting of 2b) until the timing light and the FAST are in absolute agreement. You should only have to "wiggle" from your initial 2b) estimate maybe up to +/-5 deg or so, depending on how good you were with 2B) of course. Change the timing value in the FAST around where the operating point is as it idles and make sure the actual timing seen with the timing light tracks the commanded setting.

4) Enjoy

TurboTR

 

[washingtonracer]

Thanks for the response. I went back over everything again tonight.

my crank trigger is positioned as the absolute best that i can tell
it's setup at 50 degress btdc. the ecu is set at the same mark.
I then rolled the motor over to 28 deg btdc and positioned the rotor to the number 1 cylinder. Everything is locked down. Went back and turned the motor over and still no spark. Again, by using the timing light, I am getting a spark from the coil wire, but NO spark is comming from the spark plug wires.
I did notice that my battery voltage would drop below 11 at cranking, and at that point I believe I would no longer recieve spark from the coil wire. I was using a battery charger, but it's a low model 10amp charger. After letting the charge get back up to 11.6 I would agian get spark from the coil wire. So my only thoughts in my head is A: there is just not enough charge in the battery, or B: I do not have a good ground from the block. I find both far fetched. I am using solid motor mounts which alone should be more than enough of a good ground, and I still have the ground cable connected to the block.

does anyone have any other ideas?

 

[TurboTR]

Yes during cranking the voltage will drop considerably- pretty normal. Probably not the problem.

Seems like, assuming everything is lined up properly, if it's sparking to the distrib but not out of the distrib, then either the spark is very weak, or the cap center wiper thingie that contacts the rotor is broken, or the spark is jumping from the center lead to ground somehow. Also, have you checked all the other plugs for spark, or always just the same one only? Can't think of anything else right now based on the symptoms described...

TurboTR

 

[washingtonracer]

I have tested all spark plugs, I got the battery up to full charge, and found that the light from the timing light (when connected to the coil wire) is very inconsistant. So I thought back to the pickup signal from the ecu and the wires from the trigger, both are connected good, and the ignition box does have the little led light on the side that flashes every time it recieves a signal. I verified that it is infact recieving a signal. So while the ignition box is flashing away, the timing light is not. So now I am thinking that it's a faulty coil. Brand new, but still it can be faulty I guess. So I am about to go out and pickup a cheap coil and re test. If that does not solve it, then the next step will be the ignition box it's self. I have a 6a laying around, so I will hook that up and see what happens then. But in reality those seem like the only culprits.

I'll post the results.

 

[Hawaiian Turbo]

You did unplug the dist wires(from the FAST) and plugged it into the crank trigger, right?

 

[washingtonracer]

yes I unplugged the dist and plugged in the crank sensor.

I found the cuprit though. It was my coil. damm Blaster HVC 2 coil.
spendy mofo. I went and picked up a new coil, cap,rotor, and new ground straps. Tried the coil first and it fired right up. Now I have to send in the coil and get a replacement, and then start the tunning to keep it running. Since the last time I started it, I got smart and plugged all the port holes in the manifold

Thanks for all the responses.

 

[Hawaiian Turbo]

Glad you found the problem. That's a new one, spark out of coil and into cap, but nothing coming out..... was the coil.

 

[washingtonracer]

So anyone have any idea why my idle would be at 450-550 when it should be at 1000 according to the ecu? my crank timing matches whats on the ecu, i have my iac turned way up, "still thinking there could be more with the iac at this time. the timing is set at 15degs, and this is the case from cold startup all the way up to operating temp.

 

[norbs]

SOunds like the iac is not working, check your wiring pinouts and connections