Is the backfire outt of the intake and out the exhaust??? Check fuel pressure on startup it should go to 50lb i think is the spec, when you turn the ign to run and stay.

 

slow start can be caused by multiple things. backfiring is a mechanical issue. pull the front cover and make sure it's in time.

have the tuner add some timing to the cranking tables.

 

I am having the same issue on my 08 5.3 with a tsp220 112lsa. Mine only does it if i get up to operating temp, get gas or go into a store really quick and i will have to give it gas just to get it to run. justin is still working on it though.....

 

Same **** with mine, lol I will have Justin put it on a dyno n work on it a bit.

 

Really no need to put it on the dyno. If he is just working on the cranking tables, there is no need to pay for dyno time.

 

I know the cam install is dead perfect.

 

yeah i was telling htem it cant be the cam cause u sent me pics, today it did it again, i listened for the fuel pump to kick on when i placed the key to run but it didnt. i tried a few times to crank it and it backfired very loudly!!! setting off car alarms. Finally the fuel pump came on and the truck cranked. I am still waiting on a fuel pressure gauge to see the psi. However once the truck starts it is perfect. in the morning truck starts up just fine. only during restarts or if i let the truck sit for 30 minutes or so it has a hard time. Do you guys think i can probably just change my fuel pump to a aeromotive 340 since im going boost, or will i have to get a fuel pressure regulator or tune it for new pump. Just trying to eliminate all problems that it could be. P.S. matt got another guy wanting to do a cam swap!!!!.

 

Also check the injectors for leaking down. This can flood the engine and make it hard to start.

 

stock injectors and stock pump i dont think my cam is too gnarly for the truck, but i will check in the AM.

 

If you haven't fixed this, have you checked the cam position sensor? My 99 Camaro does the exact same thing. Or have you performed a CASE learn to retime the crank and cam position sensors? Is your tach working?