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T77911S T77911S is offline
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Join Date: Oct 2006
Location: MYR S.C.
Posts: 13,435
lean miss-fire at cruise

the coil fixed the miss that i could actually feel while driving, but i still have the original miss fire while cruising. when i got the car, i found the cruise mixture to be in the 16's. idle and boost mixture was good. 13.5 and around 12 for boost(?).
runs good under boost and has good idle, its just in between that is the problem.
i some popping from the exhaust while cruising. i think i am noticing a trend that it is somewhat smooth as soon as i hit a steady speed, but the longer i stay at the same speed, it gets worse. may just be me, dont i dont know.

i have been through EVERYTHING.

no O2 sensor
no freq valve
euro FD- W/larger fuel lines
injectors- ?
054 WUR
header (B&B i think)
dual out exhaust
RUF intercooler

compression- 120 left side 130 rt.
leakdown- 4%
fuel flow out of FD/no injectors- 3 at 5.3 oz's. low was 5.1 hi 5.6
fuel flow W/injectors- no weights yet but it looks better than previous
spray pattern- not checked
swapped ignition wires with old set with better resistance
cap- cleaned and swapped
rotor- not changed
coil- new MSD
plugs- new but copper NGK's (not as good as the platinums)
timing- 26 degrees
advance works
retard works
valves adjusted
WCP- was 3.6, now 3.4 (no gauges or LM right not. brother has them)

1 could i have too much vacuum advance at cruise? i see where the dist was worked on by PO?

2 the coil was bad. could the CD be bad causing this? i have a replacement capacitor for the bosch CD. should i jsut go ahead and swap it?

3 should i drop the control pressure some more?

4 rotor? maybe i will pull the rotor. not sure if i have an old one. maybe its cracked
86 930 42kmiles [__] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD
88 BMW 325is 200K+ SOLD
05 BMW 330CI 130K:: [__] RUNNING: [__] NOT RUNNING:
08 VOLVO V70 190K:: [__] RUNNING: [__] NOT RUNNING:
Old 04-16-2013, 08:45 AM
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