Blk98ls1

iTrader: (3)

Hey guys, Ive been having a problem with my car the last few weeks. I have a 98 Z28 the second stock pump has been in the car roughly 100,000 miles, first was replaced with odometer reading a little over 110,000. Odometer is now at 207,XXX. I have been recently having trouble with hard starts, ie: multiple cranks before fire. If I prime the pump it fires right away. If I drive the car and it sits for 15 min. Or more it loses pressure and needs to be primed. However, here's the curveball, if the car sits over night 8-10 hours no priming is necessary, could that mean its something else? It has been in the mid to low 30's here for a while at night. From what I've read there's a check valve that sometimes goes bad and allows the fuel to drain back, thus causing the hard starts. Car has a rebuilt motor that makes 400 wheel, installed back in '08. Stock pump has worked well with the 30lb red top svo's, air/fuel was 11 across the board on the dyno sheet. My question to you guys is, should I just get another new stock pump? Or a new racetronix plug and play pump? I'm leaning towards a stock pump since this last one has worked fine for so long and I've read about racetronix pumps failing. Or is it something else that's wrong? Car runs fine when on, idle to full throttle it runs completely normal. Thanks for the help and input.

Blk98ls1

iTrader: (3)

After doing a little more reading it seems like it may be a bad fuel pressure regulator or the check valve on the fuel pump. Does any one know how much the regulators are?

LS1TA_956

iTrader: (1)

its most likely to be the fpr housing its a plastic one it gets oval after time and the fpr wont sit correctly common problem on 98 fbodys i am having this problem right now

504ls1

iTrader: (1)

I have this same problem on my 98. I bought a walbro and am waiting to put it on.

1ltcap

possibilities are fuel pressure regulator, bad check valve in the fuel pump, or leaking injectors.