Yeh, ACTUALLY, if I blip the throttle just before shutting her off, she sets off a gun fire type of back-fire! Must be dumping way too much fuel in there I'd say
Only explanation I can think of is:
- when ignition is shut off spark plugs stop firing immediately
- engine is still turning a little bit after ignition is off and sucks in a bit of fuel from injectors
- since no spark is present to ignite the mixture, the mixture seeps into the hot headers past the hot turbine housing and is ignited
- ignited mixture lets off a subtle back-fire
... kind f makes sense to me now.
BUT, do any of you other guys experience this at all?
EDIT: JUst went and re-gapped my plugs to 0.035", so I'll see tomorrow if that makes any difference. Either the mixture is way too rich and I'm not burning the residual fuel fast enough, or my gaps were too large to begin with. See what happens I guess
'89 911 Turbo Cab
Protomotive MAP ECU, Twin Plugged Heads, GT2-EVO CAMs, 3.3L fully finned P&C's, ARP fasteners, C2T head gaskets, Titanium Retainers, Turbo spec valves, springs & guides, 964 splash valves, GT35R BB turbo, GSF Stainless Headers, Magnaflow Exhaust, Full bay Intercooler, TiAL 46mm w/gate, TiAL 50mm BOV, Apexi AVC-R EBC, SPEC Stage3+ Clutch kit, Crane CDI Ignition