Here's what I'm running:
2006 350z roadster
Vortech v3sci supercharger
Deatschwerks 600cc injectors
Walbro gss342 fuel pump
Uprev Osiris tuner

Here's the story, I just installed all of the above parts on the car and it was tuned on a dyno making 390whp, idles fine, runs fine through all rpm ranges, everything is perfect

The problem: when I attempt to start the car when it's hot or at normal operating temps I have to put my foot on the gas to start it, if I don't touch the gas it will just crank over and not start. When it's cold it starts perfect without an issue. This was never a problem until after I did the FI install.

I had my tuner look into it but he can't figure it out. He isn't 100% familiar with uprev either so that could be a bit of the problem.

Has anyone had this problem? I'm thinking it's definitely a tuning issue.

 

You need to modify your cranking timing. -40 to 20 should be about 30, and 40 to 100 should be about 25.

 

There is a cranking enrichment table you have to fudge with as well... what's happening is ur pig rich while hot cranking. But yes it's in the tune. Mine was that way too until I got it dialed in.

 

If I try to start mine immediately after shutting it down, it won't start either. But if I wait literally like one minute, it's fine. Seems that you giving it gas wouldn't help because it would be in a "rich" state...that's awkward.

 

I have that same problem... Tuner adjusted the timing, still does it..

I personally think its just heat soak...

 

As djamps said, its not the timing but the cranking enrichment. In uprev you can adjust it for every temperature bracket. These numbers just need to be reduced in the higher temp ranges. Once you get it dialed in correctly it will start up with no issue.

 

It's actually a little more than that. Check out the uprev DIY thread where I posted all my tables. There's like 3 or 4 tables/columns for enrichment (can't remember, it's been almost 2 years since I messed with my tune) that has to be changed for the larger injectors (I explained it in the thread). Increasing the timing doesn't hurt either.

 

To be fair...to myself at least...I do have cams, a stroker, and lower compression. It's not an issue because I never shut it down and have a need to start it right back up. Stopping for gas, no problem. Starts up after just a minute!

 

I know there are crank timing tables to go with it, but I got mine working fine with just adjusting the cranking enrichment table in the hotter temp ranges, though I had to adjust them quite a bit. Using 750cc injectors, 340lph fuel pump and RFS. Ill take a look later and look for your post to see if there are ways to improve my tune. I am just glad that I switched to uprev as cobb had no tuning for this at all.

edit: thats right forgot about injector priming pulse!

 

the reason its starting when you push on the gas, is that you are allowing more air in and and leaning it out. You are too rich. pull fuel from the cranking tables at that appropriate coolant temps.

No need to mess with cranking timing at all.

hot start issues are easy to fix. If you press the gas pedal and it start, pull fuel. If you press the pedal and it still doesnt start of backfires, add more fuel.

 

I too have intermittent hot starting issues....... As I can't tune a FM radio station........I've wondered if the car being tuned during winter in the Midwest might have something to do with my starting troubles down here in 105 degree weather with an engine bay much MUCH hotter than that?

 

Thanks guys. I'll try to adjust the cranking enrichment table myself and see what happens. I'll post back here with the results

 

In for results

 

Adjusted the cranking enrichment table from 0 all the way up in each temperature range and still no change. Any other suggestions?

 

Free bump- in for results

 

No one?

 

Turning the enrichment 'up' isn't going to help when the issue is that you're already too rich. Did you bother to read the tuning 101 thread where I outlined exactly what to do with pics?

 

I had the same problem we took out roughly 40% of the priming and crank enrichment and it started like a charm until the car committed suicide on the dyno.