Tried to fire her up tonight...but no....

[Durango2k]

...did not start.

I fixed the fuel leak from the front carb (11 mm setting was wrong), fitted spark plugs after setting the firewall nearmost to almost TDC (there's a small mark on my crank damper about 1 cm before the 0 degree stamping).

Checked, and the rotor arm was near no 6 lead.

Connected a bulb in series to the spade connector on the rear side of the dissi, and rotated it until it gave an angle of about 25 degrees between engine "long line" and the dissi "straight edge", and the bulb was just lit.

Tried to fire her up in the final 2 minutes I had left before I absolutely had to leave the place, but no, not a single ignition.

Will investigate further tomorrow night...things like ignition timing, ignition lead sequence, carburation comes to mind.

Carbs- I had screwed the jet lifting screws (lower left when standing next to RH front wheel) in for about 2.5 turns, and the jet sunk down for, say, 2 mm ? Checked all 3.

I currently believe that once she runs, I will disconnect the three linkage bolts, so that each carb can behave on its own. Then use the thick adjuster screws to equalize the air volume (I have a synchrometer), and finally set fast idle/ choke.

Do I turn the dissi clockwise looking from the top until the bulb just lits ? There is an arrow on the arm indicating in counter-clockwise direction.

Soooo close as never before !

Carsten

[Mark Gordon]

Carsten, are you sure that the #1 cylinder (the one nearest the bulkhead) is at TDC on the compression stroke and when it is, that the rotor on the dizzy is pointing to that terminal on the cap? I know that you know your stuff, but from your description, it sounds like you've got #1 at TDC ( I'm unsure if it's compression or exhaust stroke) while the rotor is pointing to #6 terminal?

[Durango2k]

Hi Mark,

I am about 90% sure. What I tried was that I did short-push the starter button whilst looking inside the bulkhead nearmost spark plug hole. It blows air like a whale when the piston comes up. Quickly leave the button, rotation stops. Crawl under car, use wrench above frame and stabilizer, rotate engine cw until the -10 btdc is in line with the pointer, get back on top of car, check dissi.

Arm points to lower right, say 4 pm. Connect bulb and have dissi rotate. Bulb opens and closes, so I know points are working. Rotate dissi so that vac capsule becomes nearer to engine block and bulb goes of (thats in cw direction). Turn other way round until it just lits, ccw of course, fix dissi with clamping bolt, fit final spark plug, try....

Maybe dissi is 180 degrees out ? It sits nicely, arm can be rotated say 15 degrees against advance springs and nicely returns, but if the bulkhead nearmost blows, and arm is lower right, isn't no 1 takeoff on the cap on top left so I am 180 out ?

Or maybe I got the leads on the cap wrong by one. There are no numbers on the cap, which is sad, the Bosch caps often have numbers on them. This cap came with the car, looks almost unused, and is for sure from 1977 something or older.

I did get a pretty good white-blue spark when I test-fitted one loose plug and turned the dissi by hand, so I do have a good coil + selfmade wire set.

I did not smell petrol in the carb intakes after I had to give up, but again, investigating in this needs another 20 minutes...

Had I had more time, maybe, but I was aiming for a fast shot, and try my luck.

I do have all the tools for dwell and even an oscilloscope (anyone remember Heathkit ?), so once running I can drive it out of the shed and tune outside.

Carsten

So - for the next time...

[PeterCrespin]

You could spend a week trying your luck or you could follow the words and pictures in the book. I could not follow your explanation, so allowing for the fact I haven't fully wokenup yet (my wife gets up at 0400h) it is unlikely you have the timing correct.

An XK engine will start and tolerate a pretty wide range of timing before complaining, so don't worry about the detail, make sure you have the obvious 'macro' stuff correct. It will even fire up with two leads switched, so although I understand the excitement of a quick try-out, you must start from the confirmed correct engine position and damper marks, not rely on luck for any detail at all.

When working alone it can be easier to base everything on cylinder 6 at the front, as you can see the cam lobe through the oil cap and you can check compression stroke and TDC while turning the crank by hand from the front. You should check points opening by rotating the dizzy clockwise to take up the play, but doing it differently would not cause a non-start. If you are 100% certain your ignition is right, try pouring a very few mL of fuel into each cylinder and quickly replace the plugs. It should then run briefly on cranking and you can concentrate on carbs.

[nefematic]

Carsten, are you sure your carbs are set up correctly?

viewtopic.php?f=2&t=9690

Martin

[Durango2k]

Oh no this is it - now, that is why the air filter did not fit and I had to cut the frames !

I'll repair the frames with cardboard and hot glue, and try again with the carbs turned around.

Carsten

[Durango2k]

Ok, turned the carbs over, but still, nothing. Except that now the centre carb leaks, and I found a few water leaks (both taps and one hose to carb manifold).

I also found that with the frontmost cylinder in compression mode (put a hose tight in spark plug hole and put other end in mouth and pressed starter button for a second), the rotor is in top left position. Engine is now in the -10 degs position on the damper.

The dissi cannot be set any other way because the drive dog is D-shaped, so for now, I swapped the wires so that no. 1, the frontmost, is on the tip which just faces the rotor arm. Put the other wires of course from this on in firing sequence as per Haynes, so that should do it. Then tried- nothing.

Sadly it is again late and dark and there is still no time anywere near, I have to leave the Jag alone in the shed, dripping water slowly in the pit below it.

Carsten

[christopher storey]

Carsten : please, never again do your compression test with a tube in your mouth . You could do yourself catastrophic injury , either to lungs, alimentary tract or the brain via the cranial sinuses

[Durango2k]

Hi Chris,

I was just jokin'.... but ok, no one should read this and try it out for real....

Carsten

[Mich7920]

Hi,

"Except that now the centre carb leaks, and I found a few water leaks (both taps and one hose to carb manifold"

You are going to loose yoursef in this labyrinthe...
There is too much things why your engine don't start.
Prefer to restart at the beginning, fit out the carbs and check them for the leak and their set up. Check the rotor, gab and capacitor. Check your camshafts timing. Etc...
As Peter said, the XK engine tolerate a lot of things. It's a rustic engine. You have an accumulation of small mistake which make your engine not fire.
Follow the book, it's THE guide. Your engine will start at last.
Good work
Mich

[Durango2k]

Again, another 2 hours in the shed, nothing.

(Oh one thing first- I did achieve something, I fixed the water leaks). Maybe the engine tap still leaks a bit, but all other cheney issues ate now solved).

Getting back to the engine issue:

Lets start to analyze this:

a) engine has been overhauled. I have not checked compression, but if I take out a spark plug and operate the button it blows a strong wind in your face.

b) I have sorted the ign leads. I even fitted a set of old plugs just to see the sequence- its as per book.

c) I set the front carb so that on its upcoming cycle it blew air out, went under car, turned engine by hand so that the 10 on the damper scale is facing the pointer. Looked inside spark plug hole, can see piston is up.

d) connected bulb between coil 12V and ground. Did turn dissi until light just went on. Checked that in this situation the wire connected to no 1 is next to the rotor arm.

e) fully loaded battery. Cranking fast.

f) corrected all three needle valves on carbs to 11 mm and just "springy" there. Pushed all three pistons up in the carbs using a long screwdriver. They come back smoothly with a clunk. Did use 20W50 in the carb tops.

g) did set carbs as Haynes says: the jets were flat on their bridges, then 2.5 full turns = 5 half turns down. About 2 or 3 mm jet depth now. The large slow running screws all turned down till locked, then 2 full turns = 4 half turns back.

h) fuel pump ticks, then stops. Chambers all full with fuel.

When I remove a plug, I am not sure, but the air being pumped out does not really smell fuel-ish.

Next guess therefore- the slow running air tunnel is blocked - is it possible to use a gasket wrong way around something so that this passage "around the choke flap" is blocked, and on all three ?

If I cannot get it firing, I can still use the car as a trailer queen or put it in the garden as a sculpture. It's pretty enough for that kind of job. Or use my most- favorite tool of all times:

Carsten

[mgcjag]

Hi Carsten...are you sure you are sending the spark to the cylinder when its on its compression stroke and not on its exhaust stroke.......with the spark plugs out and the engine turning over air will come out on both strokes........If you can with all the plugs removed put a socket on the crank nut..stand by the carbs and with your right hand streached down to the crank use the socket wrench slowly turn the engine.....put your left thumb over the spsrk plug hole to block it....as you continue to turn engine you will feel the compression build and push up your thum.....you now know you are on the compression stroke for that cylinder......the rotor arm should now point to this plug lead to deliver the spark.......

[Durango2k]

I think I am pretty sure - but I will come back with Felix to find out.

Carsten

[64etype]

The "book" times the engine to #6 (most forward cylinder). As Peter mentioned earlier, look in the oil filler hole. If the #6 (most forward) exhaust lobe points outboard with crank set at TDC, that cylinder is on compression stoke.

On the recent first start up of my engine, I sprayed some carb cleaner in the air inlets to see if it would fire. It did, but no start. Messed around with jet settings and air screws and it took off. (Fuel filter and the screens in the carb inlets were new, so no likely issues there).

[christopher storey]

You say nothing about using the choke . Particularly at this time of year, full choke will be needed initially. Also, an engine which has not been run at all, or for many months, takes a significant time to get the mixture to the cylinders because of the length of this inlet tract . Several 10-15 second bursts on the starter may be needed, with the throttle held slightly open during starting ( to bypass the idling circuit )

[Mich7920]

"When I remove a plug, I am not sure, but the air being pumped out does not really smell fuel-ish."
If after a lot of try, the sparks doesn't smell fuel, that's because no fuel come in the chamber.
As Christofer said, use the stater.

Mich

[Stevejaguar]

Just a quick thought. turn the engine to roughly TDC, pull out the distributor, turn the engine ONE COMPLETE REVOLUTION, refit the distributor .

Just worked for me.

[Durango2k]

Hi Steve,

What would that change ? The dissi to engine relation is fixed, because the dissi drive dog is a D-shape, not a half-circle.

Carsten

[andrewh]

if you have had no type of ignition at all I would suspect that the timing is out, or there is no spark. Have you tested that you have a spark at the plugs regardless of where in the cycle? ( carbon brush in place?) If you have a spark then you have to check your timing. You need to get number one ( or 6) at TDC. Both valves closed. With the engine in the correct position you then need to check that the slot in the distributor drive is in the correct position ( 10 to 4 I think). Then refit the rotor arm and check that the rotor points to the correct HT lead to number 1 ( 6) . It may be possible that the distributor gear has been re assembled incorrectly relative to TDC. ( I think! I cannot recall now whether it is keyed as a fail safe) .

[Durango2k]

Hi Andrew,

ok, will Re-re-re check this. I do have a nice sequence of sparks, so timing or weak spark is the only idea there.

Did check the carbs, and found the pistons do NOT moove when cranking engine by starter motor.

Did then remove the 20W50 which is like honey on those cold days (we´re near zero now). Without any damper oil, they do lift a very tiny bit, say 3 or 4 mm upwards.

Is that ok ?

The jets do deliver fuel (take needle and poke into jet, see fuel gobbling around coming up), so that should be fine.

Carsten