spitfire Mk3 won’t start

[Jonah]

After a number of projects that the forum have  helped me with, gearbox and overdrive rebuild, stiff steering and brake pipe issues I tried to start the car today unsuccessfully 

the last time I took it out it ran roughly

there is fuel at the carburettor but a weak spark at the spark plug

ive checked electrical connections, points, cool, plugs, condenser etc which were all good

i then looked at static timing with a 12v light, I could turn the distributor to get the light to switch on at No1 cylinder and then turn clockwise to turn off, which I understand should set the timing, however there is movement in the distributor body which makes the light switch on and off erratically and setting the timing difficult 

could this be a problem with the distributor

julian

[dannyb]

Sounds like the clamp around the distributor. 

There should be a bolt at the back that holds the clamp to the pedistal and the clamp itself fits in a groove around the distributor. I suspect its not posioned right to clamp it.

Danny

[Jonah]

Thanks Danny I’ll check it tomorrow

[GrahamB]

1 hour ago, Jonah said:

I could turn the distributor to get the light to switch on at No1 cylinder and then turn clockwise to turn off, which I understand should set the timing

I assume you mean with No1 cylinder set to 6 deg BTDC for a Mk3 Spitfire.  You are looking for the point that the light just turns on/off with the slightest of movement.  Sorry if I am stating the obvious but  it was not clear from your post.

[Jonah]

Thanks Graham, you may have hit the nail on the head. I simply lined up the point on the timing cover with the dot on the pulley, then turned the distributor anti clockwise to turn on the light and then clockwise to turn it off. All of which I assume doesn’t take into account the 6 deg BTDC, is that right?

Julian 

[Jonah]

The rotor arm was pointing to No 1 cylinder while I did this 

[dannyb]

I think you may have set it a TDC. Just move the distributor clockwise  little to see if it starts. 

Danny

Edited June 2, 2023 by dannyb
Mistake

[Jonah]

Thanks Danny I can get it started but it won’t maintain an idle, it just stalls 

[Josef]

Sounds like your timing is good enough to start but not ‘right’. With the engine running, possibly with the throttle held open a little (jamming a bit of card under the throttle linkage or having the choke open a tiny bit will work if you haven’t got a helper) if it won’t hold idle, turn the distributor again till the revs stop increasing, turn it back a fraction. If the engine will run without the throttle now then close the throttle. Repeat the process with the throttle at idle, tighten the clamp bolt and road test.

 

[Jonah]

Thanks Josef, that will be my first job tomorrow

i was beginning to think I had a distributor problem 

[Jonah]

Also I measured 6deg from TDC on the pulley and set the static timing using a 12v lamp, but the car  was nowhere near starting in that position, I’ve had to turn the distributor clockwise by a considerable amount which is stretching the Speedo cable to get it to start

[Pete Lewis]

1 hour ago, Jonah said:

stretching the Speedo cable to

Its  the  revcounter cable  

Pete

if the orientation of the dizzy sounds like the drive gear is a few teeth out of time 

 

[Jonah]

How can that be fixed, bearing in mind that the car was running well previously, although on the last road trip it ran rather roughly 

[dannyb]

Did the clamp hold the dizzy and stop it turning as previous comments. Because if the clamp is tight on the dizzy body and also secured on the dizzy pedistal and still the dizzy can move around then there could be a problem with the dizzy. 

I can't see why the dizzy drive would have moved a few teeth out on the cam if you have not removed the pedistal.

Danny

[johny]

No but sometimes the fact the dizzy has been removed doesnt get mentioned by the poster😁

[dannyb]

Good point.

 

 

[Jonah]

I did remove the distributor as when I was setting the static timing I could get it switch the light on and off but a light touch on the distributor would make the light gone on again 

I thought removing and replacing the distributor might fix the problem

[Jonah]

I think I can see the error of my ways!  By taking the distributor out and turning the shaft I’ve made matters worse.

setting the static timing now with the current position of the distributor in the drive won’t get the car anywhere near starting 

[dannyb]

You probably fitted the dizzy 180 deg out.

Danny

[johny]

Ok if you removed the dizzy complete with is drive gear its very easy to put it back in the wrong position. However if you just took out the top section thats driven by an offset lug its much harder to put back in wrong. However a change of position would explain your symptoms....

[Jonah]

I took the distributor out as a unit, by drive gear do you mean the slotted lug in the engine block, if so that didn’t come out 

 

[Pete Lewis]

no its below that  and takes the drive from the camshft you have to undo the pedestal to check /change its position which controls the orientation of the dizzy body 

so angles of the vac unit and tacho drive all fit without fouling etc.

Pete

on a different line  give the rotor shaft a good push  has the shaft worn this makes timing erratic as the thing wobbles about never giving the same points gap

Edited June 3, 2023 by Pete Lewis

[Jonah]

The clamp isn’t tightened yet but I just gave the shaft a good push and there is a lot of wobble which is what I found when using the 22v lamp to try and set the static timing 

[johny]

1 hour ago, Jonah said:

I took the distributor out as a unit, by drive gear do you mean the slotted lug in the engine block, if so that didn’t come out 

Ok so drive gear untouched but it is just possible, especially if theres wear, to put the dizzy back into the slotted lug 180* out....

[Jonah]

Thanks Johny I’ll try inserting it at 180deg the other way