Slow start. Tune or just how it is?

[Robbieroflcopter]

Greetings,

I've got a Blueprint LS3 in my truck. It seems to take a while to fire. After cranking for two or so seconds it will catch and it runs good. The stock motor would start immediately. Wondering if there is something in my tune that might help or if that's just how a cammed engine is going to start. Here's my tune and a log. I've been reading up on ignition timing during cranking and think mine might be too high? It was alot lower when we started working on it but I don't remember it firing any faster. I put more timing in it so that it would stay running after it started. Let me know if you experts see anything else in my tune as well.

Thanks and Merry Xmas!

[RDF1]

Is this the LS3 with the lingenfelter 58x to 24x converter box?

[Robbieroflcopter]

Is this the LS3 with the lingenfelter 58x to 24x converter box?

Yessir. You think maybe the box is slow to provide the computer with what it needs?

[SiriusC1024]

Why is cranking spark so high?

If you're certain VE is correct then copy with axis into the cranking VE table. See the change? Project that for the rest of the table.

[RDF1]

Yessir. You think maybe the box is slow to provide the computer with what it needs?

Yep. They are known to be pretty slow to find the signal and convert it for the older pcm. So its always going to be a prolonged startup.

[Robbieroflcopter]

It looks like I have an rpm signal as soon as I start cranking. Wouldn't the box have to be working for the pc to show the rpm signal?

[Robbieroflcopter]

Why is cranking spark so high?

If you're certain VE is correct then copy with axis into the cranking VE table. See the change? Project that for the rest of the table.

Whats a good advance for cranking?

[SiriusC1024]

This is the table from a 2002 Corvette. It's pretty much the same as a 2010 Gran Sport (LS3).

cranking spark.png

[Robbieroflcopter]

Roger that. I'll try it and let you know

[kingtal0n]

You can try increasing the cranking fuel.



At the top like the "2.34" and "1.8" Those are pulsing to the cylinder seem pretty small, try like 5's or 6's see what it does. See on the left hand side column it goes '0, 1, 2, 3, 4, etc...' those are the cylinders in order, so probably the first one '0' wont fire but the second one could easily fire up quickly if the number is nice and large and the throttle is open far enough.