I think it's pretty normal. Check for a sloppy dizzy shaft too.
Hey all,
Ive been giving my engine a tune and have noticed that the timing mark flicks back and forth with regularity.
It advances a few degrees every few revolutions then settles back to the set position.
I'm pretty sure the idle speed is low enough to be avoiding vac/centrifugal advance.
There is no chain noise or issues that I know of.
What are other possible causes?
Is it a problem?
Thanks,
Ash
I think it's pretty normal. Check for a sloppy dizzy shaft too.
You should really be setting the timing with the vacuum line disconnected anyway so that should definitely not be an issue. Worn dizzy is quite likely but also check basic things like the contacts on the dizzy cap and the rotor button.
Timj.
Snowy - 2010 Range Rover Vogue
Clancy - 1978 Series III SWB Game.
Henry - 1976 S3 Trayback Ute with 186 Holden
Gumnut - 1953 Series I 80"
Poverty - 1958 Series I 88"
Barney - 1979 S3 GS ex ADF with 300tdi
Arnie - 1975 710M Pinzgauer
Thanks for that.
Its probably the original dissy so im not surprised it has some wear.
I generally do disconnect the vac line but the tuning placard says to leave it connected on this car?
you leave it connected and recheck the timing after youve gotten it running smoothly without it... ITs still fair game to pull it of to get the base set and for fault finding.
At dead idle with a closed throttle it should maintain the same advance with or without the vac line connected (dont forget to blank it).
Dave
"In a Landrover the other vehicle is your crumple zone."
For spelling call Rogets, for mechanicing call me.
Fozzy, 2.25D SIII Ex DCA Ute
TdiautoManual d1 (gave it to the Mupion)
Archaeoptersix 1990 6x6 dual cab(This things staying)
If you've benefited from one or more of my posts please remember, your taxes paid for my skill sets, I'm just trying to make sure you get your monies worth.
If you think you're in front on the deal, pay it forwards.
Also caused by the distributor clamp bolt not being tight enough,
Cheers Charlie
What I cant understand is that it is VERY consistent and rhythmic in the way it moves.
It is stable at a point for maybe 4 revolutions (dont know exactly how many). then it flicks to the more advanced point for one or two revs, then flicks back....and so on.
If it were something loose or worn wouldnt it just be wavering all over the place around the set timing point?
Not necessarily - these things tend to be rhythmic, for example, the shaft runns leaning against the downhill side until it rubs all the oil off, then the friction moves it, changing the points gap and hence the timing, oil runs in and it moves back to the same spot. Could also be the result of a small amount of hunting due to slightly wrong mixture, and the change in speed changes the position of the shaft - and the change in timing may actually cause the hunting, but the engine speed change takes a few revs due to the flywheel effect.
John
John
JDNSW
1986 110 County 3.9 diesel
1970 2a 109 2.25 petrol
| Search AULRO.com ONLY! |
Search All the Web! |
|---|
|
|
|
Bookmarks