Newbie tuner needing help with idle!

[rossp]

I havent confirmed my fuel presure but isnt the genIII non flex fuel stuff based off of 58psi? I read that my injectors are rated at 50psi base pressure. I could be completely wrong on this though. The injector part number is Denso 25326903. I have attached the tune file from the exact tahoe these injectors came out of.

[darcy]

Sorry, was looking at the wrong years of vehicle. In that case 35.59lb/hr looks prettyclose to me

[rossp]

Thanks for the help. At least I've got one thing right in the tune. I'm still fighting an idle issue where it will idle fine for 39 secs or so and then stumble and die.

[darcy]

Post a log of it idling and stalling so we can see what is going on.

Desired airflow number are MASSIVE, by about +10g/s, should not need that to idle.

[rossp]

Here is a log of it dying at idle a couple times and a short drive. Its also surging really bad at low vehicle speed when coming off idle.

[statesman]

The automotive instructions still give it a flow of 275l/hr @ 60psi, so it should be more than capable in this application @ 4bar. Agree with the line of thought that fuel pressure needs to be right.

I just had a quick look earlier and didn't find the automotive instructions. I'm always wary when I see something rated at a lower value than the intended use.

[rossp]

My problems ended up being in the ve table. I spent about an hr manually smoothing it over and it's great now. Who knew the ve table was so important haha. Also I found the fuel correction spark table. Are the values in this table added on top of my high octane spark table?

[joecar]

Yes, in SD the VE has to be good, in OLSD it has to be exact.

Yes, B5908 is added to current spark timing.

[joecar]

I take it your FPR is manifold referenced...

[joecar]

Generally, you can "cheat" by doing eyeball-interpolation of the VE table (i.e. you make the un-hit cells flow with the hit cells... this is like smoothing but really is not smoothing).