Gremo87
Proven Member
- 128
- 2
- Mar 14, 2013
-
Decatur,
Illinois
I know I'm not a probationary member anymore but there doesn't seem to be a forum for general engine questions.
My base ignition timing is very unsteady, constantly jumping from 5* BTDC to about 2 or 3 ATDC - so a 7-8 degree range. (timing pin grounded with Link)
I also have low vacuum at idle (around 12-13 in hg shown in Link from MAP sensor, 14-15 on boost gauge) and am having trouble finding the cause.
Outside of mechanical timing being off (doesn't look to be), can a vacuum leak cause base timing to be unsteady like that? Or would it remain constant if the issue was just a vacuum problem alone? (like FIAV, which I think is the only thing I haven't ruled out yet)
My base ignition timing is very unsteady, constantly jumping from 5* BTDC to about 2 or 3 ATDC - so a 7-8 degree range. (timing pin grounded with Link)
I also have low vacuum at idle (around 12-13 in hg shown in Link from MAP sensor, 14-15 on boost gauge) and am having trouble finding the cause.
Outside of mechanical timing being off (doesn't look to be), can a vacuum leak cause base timing to be unsteady like that? Or would it remain constant if the issue was just a vacuum problem alone? (like FIAV, which I think is the only thing I haven't ruled out yet)