impossible hot start

[Bjewell]

I'm working on idle tuning for my car. It will cold start just fine but will not hot start to save my life! I have tried every combination of things I can think of and nothing seems to help. I can see that it goes lean right after the RPM flare, but I can't figure it out. The setup is a turbo gen 3 DBC 5.3, SS2 cam, stock decapped injectors. I also can't seem to get my IAC count down. I've slotted the TPS and opened the blade more but the only result I get is a crazy high idle. Any help is much appreciated! PS tune 21 hot is after I matched the desired airflow to tune 20 cold. EDIT: added tune 21 which is the most current tune

[GHuggins]

Friction Airflow initial should be somewhere around 4 for hotter temps and the other table for startup airflow below that should be lower. You need to shift your iac scale to the right a few cells and probably go back to stock for a lot of it. You might want to reference the repository for something close.

[Bjewell]

I went back to stock for the RAF and it definitely made a difference. What else would you recommend? I copied bits and pieces of other similar setups in the hopes to get it start with no luck.

[GHuggins]

If I get a minute when I get home ill try to take a closer look. Post your most current tune file as well.

[4wheelinls1]

Raise the desired IAC area MAX, this limits the opening at idle. Should be 200.

[GHuggins]

Hmmm, I made some changes for you to try and while making some changes I noticed something. What map are you running? Looks like when you did the 2bar OS enhancement you didn't input your Map sensors parameters??? This will throw EVERYTHING off if it's not set to your map. I don't know which one you running, so can't say for sure, but I can say it looks like the usual 2bar OS setting... Anyway here's some changes - you need to make sure your map sensor is setup correctly.

[Bjewell]

Thanks for taking the time to look at my tune and adjust it. I'll give it a try tomorrow and see what happens. I'm using an ON3 2 bar MAP sensor and they gave me the linear/offset values so they should be correct?

[smokeshow]

If you run unconventional injectors, be prepared to handle some unconventional issues. You probably won't be able to get away with near-stoich enrichment on hot restarts like stock injectors could...going to need to dump in fuel a little longer with the cranking FA mult and afterstart enrichment. OL EQ ratio will need some love too. I'd start by getting the cranking FA mult table values pushed up above 1.0 at hot temps. And then in initial adder vs ECT, start with double the adder value in your hot restart problem area. Lot of other problems in that file...but one thing at a time.

[4wheelinls1]

I have seen before where the fuel system is set up wrong with the non-return valve after the regulator so the pressure would spike on hot shut down due to heat soak, if you have an aftermarket fuel pump/supply, put a gauge on, you can even try bleeding the pressure off when it is in a no start, the pressure spikes so high the injector won't open. The regulator needs to be able to regulate the pressure all the time.