HPFP was replaced 5 days ago when I replaced the in tank pump.
This slight misfire and backfiring has been an issue I've had since 500 miles after putting in a brand new engine. First 500 miles it was perfect. After that, started having trouble finding an idle rpm at a cold start, but if you shift out of park it immediately smoothed out and drove fine, just an occasional miss.
I did change the IC out somewhere around the 500 mile mark because I was in an accident before the engine swap and the IC got a pretty nice dent in it. Didn't affect the performance of the car very much so I left it that way for over a year. Once I put a new engine in I figured it was time to fix that.
There's no obvious signs of damage to the new IC, and everything is hooked tight. Unless there's some internal problem with it I would hesitate to think it's related and just coincidental with the timing. It is an OEM IC, nothing cheap and nothing performance.
Tried to start the car again at 10pm and just like before, sputtered and stalled out
Got it to start on the second try and stood outside while it idled. I noticed a lot clattering I've never heard before. It actually kind of sounds like the noise a starter makes when the car is already running. Like a rapid fire sparking. That noise would coincide with an audible change (decrease) in engine RPM but no change on the dash. After about a minute of idle, the sparking sound was happening very regularly like clockwork, and the car sputtered and stalled.
Restarted it a third time. That sparking noise happened twice after the engine turned over at regular intervals. The ticking of the HPFP would speed up and slow down for the first thirty seconds before settling in to a nice lazy pace. I let it run for ten more minutes and there was no additional noise and the car continued to idle without stalling.
Last edited by Zanepaul; 06-14-2019 at 09:16 PM.