Stumped on this one

[grahamwatson]

Had a good poke about with mine this morning. I too have well highlighted timing marks on the pulley and have decided that the reason I cannot see them with the strobe is that the strobe is gash. I took the strobe under the car and couldn't find the timing marks anywhere around the pulley. There is a difficult to see spot up beside the dynamo but I also ran the strobe off no 2 plug lead and could just about see the marks, blurred, at the bottom of the pulley, opposite the TDC marker. I reckon the strobe light is not sharp enough to freeze the marks.

Anyway the engine is running very sweet so I am not looking any further. But I do wonder if my distributor is in the wrong way round, 180 degrees out. There is just enough adjustment to find good timing but the vacuum advance and the LT feed both restrict further adjustment sooner than I would have expected as they come up against the block. Looking at the engine from the nearside (passenger side, RHD) the vacuum advance is on the right hand side of the dizzy. Is that the right way round?

[Ron Kwas]

James;

To eliminate Ignition Sw and Coil from suspicion, temporarily replace...otherwise, you can "diagnose" Ignition Switch indirectly, and by function...if coil puts out a nice healthy spark, its fine, and this just needs to occur at the right time and consistently!...so I'd also check how consistent timing of spark is on each cylinder...simple for No1 and 4 (connect Strobe trigger wire to each respectively and observe how much timing dances around at timing marks...hopefully not too much or Distributor deserves a careful looking over) for No.2 and 3, you'll have to add accurate marks to Crankpulley 180Deg from OE marks [Hint: Tape measure around circumference of crankpulley!] ...once you have a timing mark for 2 and 3, connect Strobe trigger to those and check timing consistency.

Let us know how you make out.

Good Hunting!

PS Both Vac Advance and Vac Retard were fitted...former is OK, later is useless, performance robbing, and should be disconnected...this graphic of Vac Retard in action should help figure out what you have:

[Ron Kwas]

Graham;

If Ignition system is working to get Spark to respective Sparkplugs, I wouldn't let the specific rotational position of Distributor bother me terribly (there are any number of rotational positions of Dist possible as a function of Camshaft Drivegear AND High Tension wire position on Dist Cap, and these would work just dandy!) but if Vacuum Actuator Can restricts Dist rotation to prevent setting timing, THAT is a good reason to change it to a position where unrestricted adjustment is possible!

Rotate only the Body of Dist (not wires) to relocate Vac Can away from fouling at engine!. To do this, (engine OFF, obviously) make note of which HT terminal of Dist Cap, each wire goes to (and position of each wire with respect to engine as seen from above...maybe even take a picture for confidence), and disconnect. Loosen Dist locking nut on collar to allow turning, and turn Dist housing close to 90Deg in desired direction to move Vac Can away from engine. Reconnect HT wires to Cap terminals using their original position as a guide (the terminals they will be connected to will now be different by 90Deg). Effectively, you have moved ONLY THE BODY of Dist, and not wires (you need to hopefully understand what I mean by this!). Retime precise Ignition timing point statically (See: http://www.sw-em.com/Volvo%20Ignitio...%20Scratch.htm ) or with a Strobe. Viola!

Cheers!

[grahamwatson]

Thanks Ron, that makes perfect sense.

Pretty disappointed with the performance of my strobe .......... until I realised that I must have got it in about 1977. I don't suppose it owes me much.

[Volvo Canadian]

I talked to a few blokes last night and one came up with the idea to disconnect the coil wire from the ign switch and just run a wire straight from the battery. I build a wire with leads, check continuity and connected - no difference. I'll try again now, as it has warmed-up some, but I think that effectively rules-out the ignition switch.

I was hoping you would show-up Ron. I will try that, but the engine hardly runs, it needs a good bit of throttle, so cannot keep a steady rpm. Hmmmm.

I am going to re-check the intermittent spark using a different gun and different wires. The MSD wires are quite thick - perhaps not allowing a good pick-up.

A friend is bringing over a spark-checker - little tube with adjustable gap - to see what we can see too.

I don't have much left - might have to resort to grasping for straws, like disconnect alternator?? Clean battery terminals? We ran a separate ground from block to battery already - no difference.

[123GT-AMAZON]

Hi ya

This might be a longshot but spark plugs can be faulty at times so just for a try switch to another set as few years back a bad batch was doing the rounds .

Also is your fuel system working correctly by the sounds Of you having to throttle up it could be on that side of things and it's not helping can only check to rule it out , by the end of this you would have fully serviced the blue dolphin and checked every inch of all the systems , charging , ignition and fuel

Maybe even fuel starvation intermittent at fuel filter or on backwards seen dad what with his eyes do that before .

Keep us posted

Kind regards
Robert.w

[Volvo Canadian]

Hi - got it running yesterday. I had: a strobe which was broken, a high-tension lead which was broken (was working, so damaged when removing it one of the 45 times), a random spark plug which got into my set of spares somehow, my other set of R spark-plugs all failed. I trusted the plugs, and checked the wires with a good plug.... What a ****-show that was.

[grahamwatson]

Dodgy strobe. Been there! Glad you got it fixed.

[Volvo Canadian]

Yeah, and 4 plugs what all went bad over a couple of months - I was pulling my hair out!

[grahamwatson]

Will have to invest in a new strobe this weekend. Anybody got any recommendations?