'96 SOHC: Engine stall under high speed and heavy acceleration.

Hi guys,

I was hoping someone in here could point me in the right direction on
fault-finding this issue on my 96' Chrysler Neon LX.

Symptoms are that car engine judders, cuts out (after 1/4 mile) and then
fails to restart after prolonged periods (greater than half hour on
motorways). Probably also normally is within about 90 seconds of an 80mph
overtake (heavy accelerations) or 80mph hill climb. If I pull over and lift
the bonnet for five minutes (its actually been between 10 and 2 mins) then
the car is fine until next long journey. If I allow the car to stop of its
own accord then coolant boils over and pours from reservoir overflow. On
each occasion the service engine light has come on and poor running is
observed until the engine light goes out again.

This first occurred last summer in 35 deg Celsius temperatures, where the in
the investigation the radiator was found leaking and replaced. I've had two
further occasions where fault occurred; light on and off within a week in
September and November. The fault occurred again just after Christmas and I
managed to get the car to a dealer to pull the diagnostic code. It
indicated that the primary ignition coil was not firing correctly, and a
Chrysler dealership local to my place of work tested the coil and 'found
this to be faulty'. Having replaced the coil personally I am still
observing the issue. I have suffered the failure a further three times,
however now the service engine light does not illuminate (although the
dealer may have masked this warning).

Looking on the 'web it seems that it could be the camshaft / crankshaft
sensor or the fuel filter. It seems the UK Chrysler dealerships I've
tried (four local ones) don't know their arse from their elbow, and are
insisting this is a head gasket issue - this is despite it being replaced
2.5 years ago (40,000 miles) and is not showing any of the obvious signs of
head gasket failure. As it seems down to myself and a local mechanic to
track this infuriating fault down, I was hoping someone could advise as to
how would I test for these faults (I don't have a 'scope handy at the
minute)? Could the symptoms be caused by any other failure(s)?

Also, can these parts be purchased on-line, locally within the UK (not from
the dealerships)? Any part number of items discussed would be of interest
(including modified crankshaft sensor), along with pricing. If I'm staring
down the barrel of a suck-it-and-see run, I want to start with the cheaper
parts. I do a regular motorway run of approximately an hour either side of
the weekend, and the car can now be relied upon to stop on both the outbound
and return journeys.

Kindest regards,
Chris (out-of-pocket and in desperation).