many HPT cars starting and no Throttle response for seconds

[lbz34]

So I have been tuning for quite awhile and have done a lot of LS cars. I have noticed it mostly on the LS2 (05+) GTO's. After a flash I have to cycle the key and then when the car starts it runs rough with no response to throttle inputs. This happens for 3-5 ish seconds. I have noticed it on 98-02 f bodies also. My car (00 Z28 w 02 3 bar SD OS) has to be started with ether after a flash, or do the 30-50 starts and play with the pedal trying to get the car to stay running. After the 5 ish second delay the car runs normal and responds fine to throttle inputs.

Anyone have any ideas on what causes this? Seems to be the ecu is in some sort of default boot mode, with no response to throttle inputs.

[mecanicman]

Do you shut the key off for a bit with the driver door open? In gm flash instructions the key is to be turned off with the door open for at least 10 seconds. This puts all the modules to sleep. They reinitialize when you turn the key forward again. I have never expierianced what you are describing, but I use this method with every flash.

[lbz34]

I will give that a shot. It is normally not a big deal as most of the cars are on relatively small 60-96 lb injectors, but my car is on 160's and it really is a pain. Only a few more months though and the real management goes in .

[04SilveradoMykk]

I do the same as mecanicman and have yet to have a problem.