Ok, attempting to reach out to the forum about this issue. Crate engine, 5.7 v8, approx. 45,000, well maintained. Had a bad brake booster and didn't have the money to fix right away. Resolved that problem but now, during startup only, the engine backfires through the intake plenum periodically, mostly after the truck reaches operating temperature. Wondering if running on the bad brake booster caused the fuel pressure regulator to fail. I've considered using seafoam as I've read in some other forums but the fact that the truck does not misfire under load, during idle or at any other time other than startup leads me to believe that the spider is doing it's job properly. Checked the fuel pressure and seems fine. I'm guessing it's the fuel pressure regulator leaking inside the plenum...pooling up.
Would absolutely appreciate the help.
Thanks
Would absolutely appreciate the help.
Thanks