I just recently installed a set of 5x0.018s and an afc cover plate. When I started my truck it had a pop while it was idling, granted my idle was below 500rpms. But after I raised my idle back to around 800 it still was doing it only at idle. After it warmed up it seemed to have gone away. Is this just because of the bigger injectors? Or is there possibly another issue?

 

when you add larger injectors your adding timing as the bigger injects more fuel sooner in the total rotation of the crank ...

might try pin timing your Ip and creep up on timing slowly as a way to tune it out .. Most likely the "Pop" your hearing is in fact the ignition of fuel .

 

you may just have retarded timing. high timing isn't usually an issue. like 4x4 said check your timing.

 

the only other issue I would think could be an issue is Overall fuel pressure as that's what's pop's the injectors ..

 

I haven't had a chance to work on my truck again, but the timing was set at 16.5* and it hasn't seemed to slipped yet. Fuel Pressure is good I have it set around 45psi. Maybe 16.5* of timing is to low for this big of injectors. I have to take another look at it the next chance I get.

 

I would start at factory Ip timing and go from there .. you may find its much easier to creep up the timing than making big increments ...