[BUZOOKA]

ok did the timing in my seirra

took it for a run today to do some handbrake take offs and reverse parks. found out my vacuum advance isnt working i was struggling to get up hill had to go back to first and even then it was a struggle and a half

gonna get a mechanic to look at that when i get a proper tune up just wondering at wat mark should i have the timing ???



cheers luke
p.s English wasn't my best class in high school so plz dont flame me

[89_tintop]

depending on the fuel you are running ..
i run premium and run my timing at about 14 or 15btdc....

otherwise 10bdtc

[Rhino]

BUZOOKA wrote:

ok did the timing in my seirra
gonna get a mechanic to look at that when i get a proper tune up just wondering at wat mark should i have the timing ???

By this do you mean degrees before dtc on the fly wheel?

The g13a say to set it to 10 btdc and the g13ba says 8btdc.

[Moph]

It's worthwhile trying premium for the extra advance you can run on the timing. Mine runs without pinging at 10btdc on 91 RON or 13btdc on 95 RON. Haven't bothered tuning for 98 RON because its more expensive and not available everywhere.

With 235/75R15 MTRs and stock gearing I found the extra advance gave me just enough to hold 110kph in 5th up gentle rises in the country where on standard unleaded I would have to drop back to 4th. Made a definite, repeatable difference to driveability at speed.

[BUZOOKA]

Moph wrote:

It's worthwhile trying premium for the extra advance you can run on the timing. Mine runs without pinging at 10btdc on 91 RON or 13btdc on 95 RON. Haven't bothered tuning for 98 RON because its more expensive and not available everywhere.

With 235/75R15 MTRs and stock gearing I found the extra advance gave me just enough to hold 110kph in 5th up gentle rises in the country where on standard unleaded I would have to drop back to 4th. Made a definite, repeatable difference to driveability at speed.

not to be a smart ass but the fuel aint gonna help when its struggling on inclines in first my vacumm advance isnt working at all

[want33s]

BUZOOKA wrote:

Moph wrote:

It's worthwhile trying premium for the extra advance you can run on the timing. Mine runs without pinging at 10btdc on 91 RON or 13btdc on 95 RON. Haven't bothered tuning for 98 RON because its more expensive and not available everywhere.

With 235/75R15 MTRs and stock gearing I found the extra advance gave me just enough to hold 110kph in 5th up gentle rises in the country where on standard unleaded I would have to drop back to 4th. Made a definite, repeatable difference to driveability at speed.

not to be a smart ass but the fuel aint gonna help when its struggling on inclines in first my vacumm advance isnt working at all

Premium fuel allows you to run more STATIC timing so even if your vacuum advance isn't working at all you should make more power than on regular fuel.
Pull the dizzy cap off and then pull the vac adv hose off the carby and suck on it to see if the advance plate moves.. If it doesn't you need to unblock the hose, check the diaphragm is still connected to the plate or replace the diaphragm.

[BUZOOKA]

did that but for some reason as soon as we connect the pipe back to the motor it stops sucking

[want33s]

Sounds like you have the hose on wrong...

Vac advance hose goes to the tit on the side of carby ABOVE the butterfly...

[BUZOOKA]

thats were it is its just not sucking till u take it off the nipple

[89_tintop]

BUZOOKA wrote:

thats were it is its just not sucking till u take it off the nipple

which nipple
carby or dizzy

[BUZOOKA]

carby nipple

[Built4thrashing]

did someone say nipple?

Do you get any suction on the nipple at the carby when rev the engine?
could be a blockage in the carby or something.


B4T

[89_tintop]

its hard to say..

blocked hose?? if there is no vac with hose on... but with hose off there i vac the hose

[want33s]

Shove a very thin piece of wire (MIG wire is good) into the tit... This should stick into the barrel of the carby above the butterfly and will clean out the possible blockage.

[LAY80N]

Are you testing it at idle. The vacuum advance only works once the motor gets above idle. Idle should be your static timing.Bring the motor up to about 2000rpm and check vacuum at the distributer end of the vac advance hose.


Layto....