View Single Post
T77911S T77911S is offline
Registered User
T77911S's Avatar
Join Date: Oct 2006
Location: MYR S.C.
Posts: 11,128
i had the same miss/bump you have, except mine sounded like a fouled plug tryiing to fire.
2500 and at a steady speed. drove me NUTS. most people could not feel it but i sure could.

finally ran it down to an air leak on #3 and maybe #2. removed and resealed intake and that problem is gone.
mark had a good point about the mixture is off due to the air leak. check all your intake bolts and spray some carb cleaner around in there to check for leaks. some water in a spray bottle works too. then have the misture set again.

you can swap the dist retard hose to the advance port at idle to make sure the timing advances. if you can regulate an air compressor down to around 10psi, you can use that to check the boost retard. then just make sure the timing is at 26 degrees and leave it alone.

did JWcheck your control pressures? make sure they are correct. im sure he did.

my brothers O2 has been disconnected for years. never heard him say anything about surging or a miss. i think his idle mixture is at 13.5 if that helps.
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 02-19-2014, 07:19 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #20 (permalink)