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1500 Spitfire won’t start


Neil Barlow
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You need to run through the standard tests, as described on a couple of recent threads here.

- pull a plug, clamp it to somewhere grounded (rocker stud?) and check if there's a spark on it when you crank over

- If not, try with the disi end of the king lead held (not by hand!) half a centimetre from the rocker stud.

- If no spark there, try touching an earth wire to the coil -ve, which should produce a spark

- If the coil is working, try opening and closing the points by hand (plastic rod!) to see if there's a spark then

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do you get a spark when its cranking, if so the ballast feed from the ign switch has failed 

do you have any clues who's electronic unit you have , maybe a picture 

has the ballast been bypassed , if yes , where is the feed coming from ?

and some cheap makes of unit have a poor reliability  some last and work fine    

has your rotor arm got a rivet in the sweep plate ?  note related as you say no spark at coil.

have you tried  disconnect dizzy lead and add  a short wire on the coil -ve and flick it to earth it should produce some spark from the coil HT

does the coil get hot if left switched on ?

sorry more questions than help

Pete

 

 

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Not necessarily as the spark may be too weak. It's much easier to get a spark in fresh air than it is once under some compression, so a weak HT can appear to give a spark with the plug visible but not actually do so where it matters. However...

Are the plugs getting wet as you crank? If you take one out shortly after failing to start, does it look moist? And does the exhaust smell of petrol?

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OK disconnect the fuel line from the carbs, stick the end in a jam jar and briefly turn the engine over. or use the priming lever on the fuel pump, if you have one (a lever I mean) You should get fuel in the jam jar.

Doug

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Neil,

You say you have fuel in the tank, is the fuel gauge telling you that? There is a common problem with the voltage stabiliser failing and causing the gauge to misread.  

I've had blockages in the fuel line, one time a fibre washer floating about in the tank and occasionally blocking the outlet. Or the fuel pump, did you discover if you have a priming lever on it?

Doug

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'The filter doesn't necessarily fill up, mine's always around 1/3 to a 1/2 full. So blockage or fuel pump then?   Easy to take the top of the fuel pump and examine the diaphragm, service kits are cheap enough on Canleys or Rimmers.  The fuel pump has a lever raised and lowered by the cam shaft. The pump is easy to remove to check this out, just two bolts, then you can wiggle the lever and see if the pump works. Careful how you put it back, lever ON TOP of the cam!

Or something far worse?!! :o The rotation of the cam is working the pump, so is the cam turning? Are the tappets going up and down? If they are you're OK!

Doug

 

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yes thats one of two small plate valves it should open with pressure stroke   and close when the lever returns the other one is more inside the case not visible

but if when you operate the lever it gives a good squirt then the pump is basically working, take care on refit  that the lever is resting against the cam and not jumped 

under the cam lobe , there should be some sprung resistance when  refitting it against its block face.

now a bit of confusion to add  the 1500  had a longer arm pump that all the others and plastic heat spacer is fitted between pump and block  

there are few replacements of these and most fit the std herald/spit   pump, this has a shorter lever and if fitted with a spacer just wont pump very much

is there any history of a pump change ????

if you fit the pump and remove a supply hose to the carbs do you get a well defined squirt , not a feeble dribble ??into a jar when cranking over

Pete

 

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