Spitting sound with RPM drop during cold start
Wondering if anyone has experienced this? I think this cropped up right after I installed a LV slip on (baffle in.)
I thought it was exhaust leakage at the slip joint (verified during a seafoam spray session, saw white smoke at joint) so I sealed it the other day with RTV Copper.
However I still get this spitting/coughing with a sudden drop in RPMs for a split second, and then picks right back up. My cold idle will go up to about 3k rpm, and this especially happens around there.
Breakdown of whats happening:
Starts on the 2nd turn
Revs up to about 3k in around 2 seconds
Spitting starts, drops down to 2-2.5k momentarily, then back up to 2.5-3k.
Couple more spits, then it steadies around 2k for a minute. No more spits.
Drops down to 1.3k when fully warmed. Runs perfect.
My mods include LV slip on, BMC filter, and PCIII USB.
Valves were done at 15k and not due for another 10k. Starts up right away so I don't think it's tight valves.
I'm about to take it to the dealer, but will also try a 0 map on the PCIII to see if the PCIII is the cause. Maybe causing strange fueling (at idle).
Last edited by 10dadeo; 06-02-2017 at 11:22 PM.