Timing on Inboard

[CAPTAIN MORGAN 2]

i want to set the timing on my 3.0 litre Volvo does anyone know the procedure I have a Timing light gun
any advice would be helpful
It has a electronic ignition no points and a prestolite ignition system

[trouty]

If it has electronic ignition - then you should NOT have to set the timing unlesss.

Unless you have loosened the dizzt securing nut and turned the dizzy at all.

The timing doesn't alter on a electronic ignition unless you do somethin dumb and move the dizzy like say you had to remove it to repace worn dizzy shafr vbearings or whatever.

Timing used to advance on dizzys with the old mechanical points on them as the cam follower on the points worn down on the cam on the dizzy shaft inside the dizzy.

Now that you have electronic circuit make n break via the electronic ignition - there is nothing to wear inside the dizzy hence the timing should never change -(which is why electronic ignitions helped keep cars "in tune" so much longer - basically all they need these days is plugs oil and filters).

So - basically you shouldn't need to do the job, but if you want to check it with a timing light just to convince yourself...then find the timing mark on the harmonic balancer pulley, clea it out and if necessary put a little white paint in it so it's easier to see.

Then find and clean the corresponding timing indicator (with all the little marks showing Top Dead Centre & the number of degrees advanced or retarded the engine is.

Once those two are clean (they get full of worn fan belt rubber + oil crud - since they can be almost imposible to see if you don't find & clean em first!)...then just hook up the timing light and run engine to see how she is set up.

Your manual will have a recommended timing setting.

Probably it's likely around 6 degrees BTDC (Before Top Dead Centre) or somewhere near that at idle.

When you rev the engine, you should see the timing advance as the vacuum advance (or electronic ignition timing advance depending on how modern it is) make the timing mark appear to move forward of the set 6 degrees or so at idle rpms.

If at idle it isn't set at what the manual recommends, (say 6 DBTDC) degrees before top dead centre for example - then - if you loosen the retaining bolt at thebase of the dizzy and slowly rotate the dizzy one way or the other while at iidle - you will see your timing advance or retard as you rotate the dizzy body.

When it's at what is should be by the manual - tighten the dizzy retaining bolt at it's base and your done.

These are general 'destructions' for most electronic ignition petrol engines...not the volvo you mention specifically - as I have zero experience with one a them.

SOME engines have the timing mark on the flywheel at the back end of the engine near where the starter motor engages the flywheel, (rather than on the front end of the engine harmonic balancer) and a cover you have to remove to get a timing light to shine in there onto the timing mark on the flywheel.

Coonazzed idea - but there ya go...

Good luck - if it aint broke don't fu@k with it is always good advoce.!

If it won't run git a bigger hammer.

Cheers!

[Mud Runner]

It's tough to answer your question not knowing the year & model of the engine. In the older engines like the AQ171 with electronic ignition the timing could not be adjusted at the distributor. You check the timing at specified RPMs. If the readings are different, you have to check the crank sensor and control unit & replace as needed. You also have to check top end rpms(6100 to 6300). If higher, then the control unit has to be changed. This is assuming that the engine is propped right.



850 rpm------ 8-12 degrees BTC
1500 ------ 12-16
3500 ------ 21-25
4500 ------ 22-26
5500 ------ 29-33

Hope this helps.


P.S. I was typing while Trouty posted but he's accurate when he said:

Good luck - if it aint broke don't fu@k with it is always good advoce.!

[trouty]

Ohh a couple more thoughts spring to mind.

On old cars that used to have points rather than electronic ignition. As mentioned the timing used to advance as the pre set points gap closed up as the bakelite cam follower on the points used to wear down as it ran on the dizzt cam.

As this went on and the timing got more and more advanced - a symptom you would often hear when driving the car was that when under accelleration - the engine would "ping" i.e start to ignite each cylinder a poofteenth of a second too early before the valves were 100% closed....

This condition if not remedied (i,e the engine tuned up) could lead to burned valve seats.

Worn points was why engines were regularly needing tune ups.

The pinging noise was the clue you needed a tune.

Now days with electronic ignitions, basically that advanced timing condition causing pinging under acceleration basically shouldn't occurr.

If when you've done your timing, you accelerate the engine and you hear it pinging under acceleration - then you have done something wrong and have it too far advanced.

The manufacturers manual should have the correct timing degrees in it.

Sometimes - with the old vacuum advance dizzys, you actually had to remove the vacuum advance tube from the body of the vacuum advance mechanism on the side of the dizzy and plug the tube with say the head of an old spark plug or similar...then set the timing to it's recommended degrees BTDC, then re attach the vacuum tube to the vacuum advance mechanism, and see how she goes.

The workshop Manuals used to show you how to do this..from memory

Hope this helps.

Cheers

[CAPTAIN MORGAN 2]

Thanks a lot gor all the help, you are right I checked and the engine cannot be timed so I think I will search for a vaccum leak around the Carb, also check the wheel and make sure it is picthed right