Got the idle and drivability pretty good now but on startup it revs up to almost 2000 then almost dies then revs up again and finally catches. Any ideas?
05 300c 5.7 small cam and edelbrock intake
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Got the idle and drivability pretty good now but on startup it revs up to almost 2000 then almost dies then revs up again and finally catches. Any ideas?
05 300c 5.7 small cam and edelbrock intake
Did you try putting the desired startup airflow (ECM 35020) back to stock? In your tune I see startup airflow bumped up after ECT of 50F but colder temps are untouched.
Put it back to stock same thing. The first time I start it after a flash I need to get it to idle with my foot then it learns and ever start after it is one or 2 flares then it catches.
any ideas?
Not sure if you resolved your issue but here are a couple of things to try:
1) bump up your entire desired start-up airflow table by 25%
2) in your spark min vs time, make the entire table +5 degrees
tried that. Didn't change at all. Same issue
Get rid of all the negative spark in your minimum spark table, when rpms come down you are right in that spot on your table (map is near 100kpa). That should help. Also your Minimum Startup spark looks funky with all zeros for half of it, I have small positive numbers (3-4*) through to around 1 second of engine run time.
Lastly your lower portion of the VE is close but still lean. Most cams like to run on the rich side of things, when rpms are coming down after first fire up, it appears to be lean and near a stall. I would add the 5% your are seeing on fuel trims once it goes into closed loop to the bottom portion of your VE and definitely smooth it out, has lots of weird ups and downs that'll tickle the idle smoothness to no end (you have spots where it goes up and down and up again going down a column, that shouldn't happen).
made all the suggested changes. It made a difference in the cold start, which is basically perfect now. But it still does the same thing on hot start. Idles up then falls down and then catches.
Here's my updated tune and start log
The only way I was able to prevent my car from doing this was to add to the idle speed run time. I changed from 176 to like 600 then 300.. It starts and flares and comes down slowly so that it doesnt stumble. This may not be the proper fix for it but it did work in my case. I have a 6.1 with a mild cam and a Hellcat Throttle body..
Tried that too. It starts then falls and almost stalls then settles at the higher rpm. Basically the same just idles higher once it catches.
its gotta be the low low end of your VE table. Once it fires, it moves off the startup inj table and moves to VE based fueling. try adding some more fuel to the lowest rpm columns.
Try to see if this work.Quote:
Originally Posted by jabbott1
Set you Min Phi to 1.0