MS3x help with starting/cranking tune
 

I need help getting my tune to work. The attached tune require me to put the throttle to 10% to help it turn on. And I have spun my motor backwards too much/detonation. I would like some help with my tune.

bumpity

bump

Sorry- would love to help, but have the same problem. I'll try and retard timing during cranking some more.

I agree, every now and then the crank spins backwards, which means its too retarded. This tune that I have likes the 80 degree days I have , so...how would that manifest in colder days, I know I have enough fuel as it indicates 12.5, but when I change the timing and it cranks well I get 19:1 which means its working. It doesnt turn on so..something still not right.

Heck, I'm back to the stock ecu, other than this mishap, using a Megasquirt is pretty easy. After I saw auto-tune work its magic I began to understand how to tune.

it's impossible for the crank to spin backwards.

if it's combusting in bangs and not quite starting, or you need throttle in order for it to catch, you need to lower the crnaking pulsewidths in that CLT temp zone.

My brother saw it spin backwards during cranking. Terrible terrible sounds. Ploof, plop, bang. Ever took an engine apart after this? I doubt visually I will be able to see this when I open the engine, but just wanted to know. Good thing I'm moving towards a 01 block.

As far as cranking goes, if I move timing one way it hardly seems like its going to fire. If I move timing the other way there's a sweet spot where it just doesnt catch, but spins nicely. And then there's the "i think this car has a carburator" zone where I think I'm choking it and tons of bangs go on.

I'm pretty sure that this actually can happen. If your timing is too advanced during cranking and you're cranking somewhat slowly, then you have combustible mix in the combustion chamber, the crank position is BEFORE TDC and when you get a spark it wants to go backwards. Cranking usually stops at that point. Causes the starter to sound pretty funny too!

^that's what I was trying to say. Thanks stefanst.

Now, Brains, how much do I adjust the cranking pulse widths?

Brains halp

bump. still need help on cranking pulse

120ve from -30c to 5c
113ve at 10c
102 at 15c
91 at 20
80 at 25
72-30
66-35
63-40
62-45
61-50
60-55
59-60
58-65
57ve from 70-125c

I'm running at 0 degrees of timing during cranking to avoid that exact problem noted in the beginning posts.

How do you set 0 degrees during cranking? I'm having this same issue. Based on this screenshot, at the lower temps is it adding timing or subtracting timing?

Could you also post a data log of an attempted start?

I am running adaptronic so how i sent my cranking timing wont help u however in Adaptronic cranking settings timing do not get overwritten by air temp.

Here are a couple of quick datalogs to show the cold start issue.