i got some advice from you a post or two back about slow starting, first of all thanks for that, now im working on my 67 camaro,

heres what i did

iac hold 40
ramp decay 2 sec
rpm above idle to start 1000
re enable 100
startup iac hold 3 sec
decay 4 sec
rpm to run 0

i also turned off the cam sensor


my first question is, is there any negative effects of turning the cam sensor off? will it get worse gas milege loss of power or anything??

also now its starting pretty quick but sometimes it syncs then fires but dies, would this be crankking fuel ?? maybe i need to raise it or could it be something else

any help is appreciated

 

by the way its not to far off from a stock ls1, forged iron block with callies compstar rods, diamond nitrous pistons, stock crank, bored to ls1, 317 heads, zr1 cam, ls1 intake holley headers

 

anyone?

 

Turning off the cam sensor will cause a random no start upon cranking. The PCM can't see which phase the cam is on, so it defaults to one. If the engine stopped rotating while on that default phase, it'll fire right up without issue. If not, it'll burble through the exhaust, backfire, and not start.

 

is there a way to get it to start decently fast with the cam sensor on?

 

I haven't worked with the Holley stuff enough to have the tables memorized, so I can't help you there.

 

you need the cam sensor...
you can see when it syncs in the software...
just look at your rpm signal... it will say error... then syncing, then you will see rpm..
might take as much as 2 seconds to sync...

if it doesnt sync.. then solve the issue with either the cam or crank sensor
otherwise, it should start as soon as it sync's as long as fuel is close...

fueling has to be close or it wont do anything...

see what spot in the cranking fuel table its at.. and push it up or down slowly...like .2 lbs/hr at a time...
just a guess... but it should be somewhere in the neighborhood with the default ls1 setup they have in the global folders...
then you can push it up or down from there.

also, try going with a little less cranking spark...
I think the default for the ls1 setup is 15*...bring it down to 10*, seemed to help on my setup..

and FYI... My car starts Immediately as soon as it sees sync between the cam and crank sensor...

as soon as your car gets started, if it does right away, its most likely the after start enrichment
and it starts using the VE table as soon as its past the enable to run rpm value and the enrichment has decayed.

 

ok kewl thanks man i really appreciate the help

 

with your rpm to run...set to 0, it will look at your ve, not your cranking fuel... so you may need to push your ve table around, or raise crank to run rpm to a higher value,... setting rpm to run to 0 is only for troubleshooting...


also, once you get it to fire up, you can look at your log and see what the wideband does to fine tune starting fuel...
just make sure the wideband is fully warmed up and ready before you try to crank over the car.



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ok kewl thanks that makes sense, what would u set the rpm to run to 100? 300?

 

400 is fine once you get the fueling sorted out...

 

alrighty i think i bout got that tuned in now i got a new problem, when i start it and the engines cold it idles fine and when its fully warm its fine, however somewhere in the middle if i stop at a light or something it surges from 400 to 1000 rpm and its only when its in a certain temp tho, would this be timing or fuel or both

 

What is your iac % hot idle. I have mine set up so it is about 5% and the low idle went away when pulling up to a light

Tim

 

Fuel Related most likely...

but, double check your timing tables..
I make sure the Timing adder/subtractor table is zero'd out and onlyl pulls a few degrees when operating coolant temps go way high...

as for fueling...
you can look at how much closed loop compensation it has, and adjust your Engine Coolant Temperature enrichment table so that it stays closer to a correction of only a few percent..
I make mine the same values for all MAP's and only adjust it for ECT... guarantees more stability that way..
example being entire column at -40 is all 130%, entire column at +80 is 110%, entire column at +180 is 100%....and so forth and so on.