420 SE non starter

[alext]

Hi
Can anybody help ?
1988 420 S class, just refuses to start, plenty of life in battery but no spark until it starts to cough and splutter, when it tries to turn over, there's a good spark but it just wont catch - someone suggested the crank sensor might be at fault ( before its suggested, the ignition amplifier module has been replaced ), where is it ? how much is it ? is it a diy job ?
Thanks

 

[jibcl500]

if theres a spark I wouldnt say the ignition module is at fault, how healthy is your battery????? try a fresh battery before anything else.

jib

 

[alext]

hi, thnks but the battery is new

 

[television]

The crankshaft sensor is a good reason not to start, if there is no spark and the ignition amp has been repaired

 

[alext]

Hi, thanks, just to clarify, there is a good spark when it TRIES to start, but then the spark disappears and its obvious it's not gonna try again.
Where will i find the crank sensor ?, is it a diy replacement ( have garage facilities) any idea what they cost ?, thanks