wont cold start

[dlove]

working on a friends car- "346, AFR 205s milled to 62cc w/8019 springs, Pat. G cam (231/235 LSL), Fast 90, NW 90 TB, 42 lb racetronix, Kooks 1.75" LT's, Kooks Y w/cats, Yank PT4000"

On a cold start the car wont start unless you give it a decent amount of throttle then hold it for a few seconds and the car will sometimes keep it self running. I got the ve table all dialed in, as it starts warm just fine. It does smell a tad rich at times when trying to cold start.

I have tried to add a little, a ton, everything to the desired airflow table. No success. I tried changing the desired idle speed to like 2000 when cold and no matter what i put it only idles around 1000.


It is hard to get a good log since it is a cranking issue, and for me to get it started i have to hit the gas.

from what i have seen:
Idle spark is around 28
KPA- 55 (i thought maybe a tad high, but no vaccum leaks found)
IAC- I have seen sit at 310 when cold. It settles around 50 when hot. The throttle is set open about 3 degrees and tps values reset.


I attached the Tune file. I went threw what i thought was everything and tried changing everything to a know good idle on a similar setup, but with no luck.

[Aloicious]

working on a friends car- "346, AFR 205s milled to 62cc w/8019 springs, Pat. G cam (231/235 LSL), Fast 90, NW 90 TB, 42 lb racetronix, Kooks 1.75" LT's, Kooks Y w/cats, Yank PT4000"

On a cold start the car wont start unless you give it a decent amount of throttle then hold it for a few seconds and the car will sometimes keep it self running. I got the ve table all dialed in, as it starts warm just fine. It does smell a tad rich at times when trying to cold start.

I have tried to add a little, a ton, everything to the desired airflow table. No success. I tried changing the desired idle speed to like 2000 when cold and no matter what i put it only idles around 1000.


It is hard to get a good log since it is a cranking issue, and for me to get it started i have to hit the gas.

from what i have seen:
Idle spark is around 28
KPA- 55 (i thought maybe a tad high, but no vaccum leaks found)
IAC- I have seen sit at 310 when cold. It settles around 50 when hot. The throttle is set open about 3 degrees and tps values reset.


I attached the Tune file. I went threw what i thought was everything and tried changing everything to a know good idle on a similar setup, but with no luck.

a few of your startup tables are a little strange looking to me, like table {B4304}, you've got zero airflow correction at at 0*c? try this tune, I made a few alterations to some of the starting tables, see if it helps or not. (according to the tune its for a '99 camaro, w/5.7L, I pulled some data from the stock '02 5.7L camaro tune, its probably not going to be perfect, but I would think it'd be closer.) you might also want to look at the cranking VE, looks really low, but using your VE and Marcin's Cranking VE table its pretty close, you sure you're normal VE table is good? you can also look at your commanded fuel while cranking, its a bit lower than stock as well. but here's something that might give you a start on it.

[dlove]

I will try it out. Car started no problem and drives great today on my tune. I was having issues with it restarting as well, if I was to turn the car off then try to restart it. I didnt try this, this morning though a I wanted to make sure it would warm up fine on it's own.

I opened the TB a tad more and reset the TPS. I think this seemed to fix a lot.

I thought the ve table seemed a tad low. So, I reprogramed the LC1 and tried it again with the same results. My log today, shows the fuel trims pretty low.

cranking ve table came from the calculated table.

[Aloicious]

I will try it out. Car started no problem and drives great today on my tune. I was having issues with it restarting as well, if I was to turn the car off then try to restart it. I didnt try this, this morning though a I wanted to make sure it would warm up fine on it's own.

I opened the TB a tad more and reset the TPS. I think this seemed to fix a lot.

I thought the ve table seemed a tad low. So, I reprogramed the LC1 and tried it again with the same results. My log today, shows the fuel trims pretty low.

cranking ve table came from the calculated table.

yeah, I've been working on some starting issues recently and the cranking VE pretty much solved it. I'm wondering if your actual VE table is off, it looks pretty low also, and almost too smooth, when I cammed my L31 and swapped intake manifolds, the VE lowered slightly in the low load, low RPM ranges, but increased a decent amount over the majority of the VE , and my cam is pretty mild. your VE table is significantly lower the a stock '02 camaro 5.7L almost all the way across the board. you say your trims are low, are you turning the trimming OFF before VEing? make sure you're running in complete open loop speed density before actually doing a VE tune (sorry if that seems a little obvious, I don't know your tuning experience, so I just call it as I see it.)

I don't have much experience with the gen III motors, but I am running the same '02 OS on my 411 controlled Gen 1E vortec 350, and I've found that the things that helped the most for starting issues are a good cranking VE extrapolated from a accurate main VE table, the airflow correction/friction tables, and the commanded fuel while cranking table.

[dlove]

yeah, I've been working on some starting issues recently and the cranking VE pretty much solved it. I'm wondering if your actual VE table is off, it looks pretty low also, and almost too smooth, when I cammed my L31 and swapped intake manifolds, the VE lowered slightly in the low load, low RPM ranges, but increased a decent amount over the majority of the VE , and my cam is pretty mild. your VE table is significantly lower the a stock '02 camaro 5.7L almost all the way across the board. you say your trims are low, are you turning the trimming OFF before VEing? make sure you're running in complete open loop speed density before actually doing a VE tune (sorry if that seems a little obvious, I don't know your tuning experience, so I just call it as I see it.)

I don't have much experience with the gen III motors, but I am running the same '02 OS on my 411 controlled Gen 1E vortec 350, and I've found that the things that helped the most for starting issues are a good cranking VE extrapolated from a accurate main VE table, the airflow correction/friction tables, and the commanded fuel while cranking table.

car was in open loop with the maf getting failed. Probably the 5th car I have auto ve'ed with great success. No expert, but past novice lol. I do agree that it seems low. Car drives great with no problems at all. I smooth the table just enough between logs on the auto ve. Then relog again and make more adjustments.

I have seen different command fuel while cranking tables. My current comes from a 00 ls1. The newer one (02) is a bit leaner and has 22:1 ish across the bottom.

[Aloicious]

car was in open loop with the maf getting failed. Probably the 5th car I have auto ve'ed with great success. No expert, but past novice lol. I do agree that it seems low. Car drives great with no problems at all. I smooth the table just enough between logs on the auto ve. Then relog again and make more adjustments.

I have seen different command fuel while cranking tables. My current comes from a 00 ls1. The newer one (02) is a bit leaner and has 22:1 ish across the bottom.

yeah I figured you knew what you were doing, but thought I'd make sure that wasn't the problem with autove. I've had better luck tuning my VE w/o smoothing it, but that won't cause any of the problems you're having. hopefully you are able to find out whats up with it. let us know when you do, I'd be interested in what is causing the issue.

one other thing I thought of is that when mine had trouble starting and I would have to feather the throttle for it to start, it would smell a little of fuel, it made me think it was really rich (kindof like what you mentioned), but leaning it out just made the starts more difficult. it wasn't until I started adding fuel via cranking commanded fuel and increasing cranking VE table that it actually got better, the fuel smell also went away as well after making it richer, not sure why, but it worked.