Thread: TIMING concerns
View Single Post
T77911S T77911S is offline
Registered User
T77911S's Avatar
Join Date: Oct 2006
Location: MYR S.C.
Posts: 13,445
TIMING concerns

as you know, i have been battling this annoying miss. sounds like it on the rev limiter.

anyway, i have been looking at the timing and AFR's and their relationship.
both vacuum ports work. i can see the timing advance/retard with pressure or vacuum. the mechanical advance works.
first off, at idle and the retard not connected, my timing mark is just ppast half way between Z1 and 26 degrees, i figure around 15 degrees.

note, i have removed the retard because i do not have any solenoids to block boost going to the retard pot preventing the boost side from retarding the advance. on that note, with it being connected and the PO running 1bar, shouldnt that have killed the motor? i am runng it at .8 now
on that same note, i have forgotten to reconnect the advance/boost retard line several times now and have gone on boost. that has not killed it. (?) also, with it not connected, i cant really tell any difference in the way it drives. (?)

the other day i was reading 14.4 at 2500rpm. i removed the vac advance and it got leaner(???) to 14.9. with the tests i ran on my 77 with timing, it should have gotten richer.

my vac pot has been shimed for some reason. anyone ever seen this before?

with the vac advance connected and when i check timing, the timing looks like it around 30 degrees. so i know it is advancing. with the vac removed it is at 26 degrees.

i am thinking about removing the intake to check for a cracked intake block, but i just dont feel like that is it because all the plugs look the same.

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 05-29-2013, 07:17 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)