What should the RPM be when setting timing on 2F engine? Thanks
Setting timing on '77 FJ40 2F
- Thread starter MarillaMarauder
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1911
chupacabra
Per the factory service manual, 950 rpm, with the distributor vacuum hose(s) plugged.
- Thread starter
- #3
Thanks!!!
- Thread starter
- #4
I've noticed that the timing doesn't matter whether the vacuum hose is plugged or not? What could be possible problems?
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- #5
Let me clarify. When I have the gun on the Timing BB, there tis no change in its movement no matter if the vac hose is connected to dizzy or if it is off and plugged.
4Cruisers
SILVER Star
The distributor vacuum advance (other then the additional vacuum diaphragm for HAC - high altitude compensation - on the later FJ40s and FJ60s) only kicks in under acceleration when the throttle plate opens past the orifice in the carburetor, so it should not be a factor at idle.
1911
chupacabra
Your vacuum advance is not functioning.
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- #8
What symptoms will I see if the vacuum advance is not functioning? How do I check if is actually working or not. As of now it starts and runs but it knocks at higher rpm. Also runs very rich no matter how I adjust carb. Never did this before. Oil level good etc.
1911
chupacabra
Poor performance / lack of power at higher rpm's.
The procedure is in the factory service manual, but basically you just apply vacuum to the dizzy and see if the timing plate moves (rotates).
Indicative of too much advance on base timing, or carbon accumulation on the head and valves.
Separate issue.
1911
chupacabra
Per the FSM, timing should be set at 950 rpm, not idle.
4Cruisers
SILVER Star
Thanks, I forgot that.
What FSM says that? My 2F Engine Repair Manual says to set Timing at Idle Speed. Idle Speed is 650 +/- 50 RPM.
1911
chupacabra
Last edited:
OlYellr
SILVER Star
middlecalf
SILVER Star
^ It (#10 above) says ignition timing 7-deg BTDC/Max. 950 rpm
I'd set it at the idle speed (650) cuz I'd want everything pinned to when the throttle starts to open up.
I'd set it at the idle speed (650) cuz I'd want everything pinned to when the throttle starts to open up.
Last edited:
OlYellr
SILVER Star
Mine is the 1991 Version. It doesn’t mention the 950 Max. It only states “at idle speed”
1911
chupacabra
The factory service manuals have changed over time for sure. As another example, the 3FE service manual gives torque specs for the oil pan and pushrod side cover bolts (among other things) that were never mentioned or listed in the F/2F manuals.
South Texas 97
GOLD Star
I read that as 7 degrees BTDC max, at 950rpm. but I see how it could be interpreted as 950rpm max. I would expect the max after the 950.
