a little help here with startup please.

[firefly9r68]

Ok im trying to get this thing to start right and i cant quite get it. sometimes it will fire right off perfect and sometimes it will crank forever. and it doesnt matter what temp it is at either. another thing,i have set my RAF table(from stock) all the way up and down in 2's (took forever..LOL) so i must have something else off a little. so if someone could look at JUST THE STARTUP stuff in this tune and help me out i would greatly appreciate it!. o and BTW once it starts it runs PERFECT cold or hot.

mods
408 stroker.
9.8 comp
afr 225's P&P
232/240 .595 .608 114+4
stock intake and P&P TB

[BBA]

Put timing cells under 1000 RPM to 30º for all airflow cells. Should start fine every time. (It will idle better too).

Just one side effect of a cam with a lope, it messes with airflow so much timing get's whacked.

[firefly9r68]

what about my startup airflow? does it look ok?

[firefly9r68]

and all cells on what tables? all of them? low/high/castdown/...all?

[firefly9r68]

ok i changed the idle spark table, and the high and low OCT table and castdown, and it still only has 11* of timing at startup/....

[firefly9r68]

ok a little more info. i have figured out that if i crank it for about 2 seconds then stop it, then let it sit for a second or two and try again it usually starts right up. but no matter what it will not startup on the first try. adding the timing did actually add to the startup timing, and it raised my idle.

[Pulse_GTO]

How does the fuel pressure look?

[firefly9r68]

58-60 psi

[firefly9r68]

also tried it with it set at 42 psi. no difference.

[DSteck]

I can't view your calibration right now, but it sounds like you don't have enough startup airflow.

[firefly9r68]

i went from 10 G's all the way to 50+g's and never got it to fire off on the first try. i did it in 2 g increments like you are suppose to...........

[ktoonsez]

So how much have you added to the "Final airflow minimum" and "Startup Airflow" tables? That cam really isn't that big, it soulh work by adding 4-6 grams in the "Final minimum" and "startup airflow" tables.

[firefly9r68]

thats what i thought!!!!! and no its not huge the heads are P&P alot too though. whats so weird is it run PERFECT as soon as it starts.

[ShoddyHog]

I've had the same problem for a year, and I never have found the solution.

I've tried BBA's timing thing, tuning my min idle airflow tables per 5litereater's method, and I think 1,000 different combinations of startup airflow and startup fuel. No matter what I do, I get missed starts. On the 2nd crank, she'll fire right up. Car runs smooth as silk, gets good mileage, and hauls ass.

Problem started when I had my cam installed, and did not go away when I went to L92 heads.

Gerry

[firefly9r68]

I've had the same problem for a year, and I never have found the solution.

I've tried BBA's timing thing, tuning my min idle airflow tables per 5litereater's method, and I think 1,000 different combinations of startup airflow and startup fuel. No matter what I do, I get missed starts. On the 2nd crank, she'll fire right up. Car runs smooth as silk, gets good mileage, and hauls ass.

Problem started when I had my cam installed, and did not go away when I went to L92 heads.

Gerry

exactly!!!!!!!!!!!!!!!!!!!!!!!!! pisses me off!!!! and i look dumb when im trying to start my car in a crowd...LOL...

[ktoonsez]

firefly9r68:
Here is something easy to try (but you might have already tried it I'm sure). Put your idle spark table to 25* in the areas you actaully hit and do the same for the HO table. Put your startup airflow and final minimum tables back to stock and then multiply both tables by 1.55. Here is the trick, the computer usually gets pissed at you when it gets flashed so don't get frustrated if it doesn't start on the first try. So get the car started, just drive around the block and give it a couple of good revs in neutral, then shut it down and try to start it back up. The PCM is really twitchy after a flash, have seen some really wierd things especially with AFR after a reflash. Give that method at least 2 chances before giving up on it.

[firefly9r68]

firefly9r68:
Here is something easy to try (but you might have already tried it I'm sure). Put your idle spark table to 25* in the areas you actaully hit and do the same for the HO table. Put your startup airflow and final minimum tables back to stock and then multiply both tables by 1.55. Here is the trick, the computer usually gets pissed at you when it gets flashed so don't get frustrated if it doesn't start on the first try. So get the car started, just drive around the block and give it a couple of good revs in neutral, then shut it down and try to start it back up. The PCM is really twitchy after a flash, have seen some really wierd things especially with AFR after a reflash. Give that method at least 2 chances before giving up on it.

I will try this right now.

[ktoonsez]

OK, good luck! Let me know if that worked out for you.

[firefly9r68]

tried it but it didnt work for me, one thing i did notice no mater what i set the timing at the startup timing is always 3-6 * here is my latest tune it is the best yet for startup.

[firefly9r68]

i now always get a p0341 Cam sensor SES when i stat the car. but it is running just fine......... and it only does it on startup. i can drive for hours and not get the light but start it and it comes on