I have noticed that when I am cranking my subs my car seems to jerk and seems like the fuel is cutting out. I am pretty sure that in-tank pumps are electronic and maybe the subs are pushing too much power through and not enough for the pump? I have never noticed dim lights or anyting else that hints at a weak battery or altenator. I am guessing the pump is really weak because im also having a hard time starting after it sits for a while usually taking 4-5 cranks to start. Any advice on this?

 

Yeah, don't play your music so damn loud! LOL
It does indeed sound like the subs are taking the power needed for other systems.

Maybe, you're getting the pump to vibrate at its resonant frequency and therefore upsetting it..... sorry.

Mark.

 

if the voltage drops too low to the ECM, it won't work. 9.8 volts is the minimum voltage the ECM will work off of, & even at that voltage it may not start & it for sure won't run right.

i would look at the power supply wiring going into the car.
your battery connections, the fuse links, & the bulkhead connector would be a good place to start.
also make sure all of your grounds are good, battery to motor, battery to body & motor to body along with the computer grounds.

 

Sounds like it could be a ground problem...
subs shake = loose conection to ground = somthing starts droping voltage = loss in fuel pressure.
Its possible the feul pump could studder under intense vibration but highly unlikly. Ive had levels as high as 165db inside my bird and no fuel pump problems.

good luck.

 

165db? oh ****, you still have windows in your car? that thing cranks

 

Well since our cars dont have metal inlays for the windows to go into at the top . If you get that much pressure in the car the windows just flap out and release all the pressure. so its hard to get much louder in these cars. Even with a bunch of peeps pressin in on the windows they cant keep it seeled.

 

I presume you weren't in the car at that sound level? LOL