fuel pressure regulator replacement
 

2000 GMC 5.3
hard starts

In a previous thread we talked about hard starts and fuel pressures. A checkvalve in the pump was thought to be bad requiring a complete fuel pump assembly replacement.
I've been waiting to see how that turned out but hasn't yet. So today I took a look at mine. It's been hard to start at times for a month or so. Touch the key and it'll start right up some times and spin over and over then start smelling flooded other times.
With the engine off I pulled the vacumn line off the fuel pressure regulator and gas ran out of it. That's not right.
So I replaced the regulator. A 5 minute job. A twist of the key and it busts off like new now. Idles better too.
Be sure to pull that small oring out of there or the new regulator won't go in. I'm pointing to it in the 4th pic.
So mine turned out to be the regulator instead of the checkvalve in the fuel pump unit being the culprit. $45 instead of $300 for a pump. ;)

Re: fuel pressure regulator replacement
 

Good info. Thanks for that write-up