Injector Question

[IndyNova]

have a quick question, I currently have gt-500 injectors
(66#/hr @ 58psi fuel pressure) in my 6.0, that has a "start-up" tune in it. When I start the motor, it runs for 5-10 seconds before it starts popping and backfiring. My tuner wants me to put some street miles on it prior to the dyno to work out the bugs. Would having the bigger injectors installed, and say, the stock injectors parameters in the tune cause this? Thanks for any help/advice you guys can offer.

[snappytravis]

Going to try to help you on this one,, it's free advice, may not be good but it's free.
I am running holley hp on a ls3 with fast 85lbs injectors. I had to email fast and get the injector off time and install in the computer. I am not sure if you have done this or not. Here is what they emailed me back on my injectors
8V - 1.76 ms

9V - 1.29 ms

10V - 1.00 ms

11V - 0.78 ms

12V - 0.63 ms

13V - 0.50 ms

14V - 0.41 ms

16V - 0.19 ms

Good luck

[novahollic]

If you still have a tune that is set up for the factory injectors, it is going to run very poorly with the larger injectors in it.

The reason it takes a bit for the roughness to start is because it is waiting for the o2 sensors to heat up and start making corrections. Once that happens, the corrections are made based on stock injector data in the tune.

I would recommend putting the stock injectors back in for the break in miles, and then letting your tuner get the new ones dialed in when the time comes for a tune.

[IndyNova]

Thanks guys, I appreciate the help.