940 Turbo randomly stalls and wont turn on

[ThermalShark]

Originally Posted by TonyS9

CPS+ingition amp problems will be apparent with the tacho needle not moving. This is a good diagnostic tool. If the needle moves a little while its trying to start but not starting, its not the CPS or ignition amp.

When trying to start the needle does not move. I have already replaced the CPS with a brand new one, but I have not thought of the ignition amp.

[Laird Scooby]

The ignition module/amplifier often gives similar symptoms to those you describe.
Often it can be cured by removing the module, cleaning the aluminium on the back with something non-abrasive (alcohol wipe or similar), clean the mating surface on the body where it mounts the same way, applying a fresh coating of thermal/heatsink compound and refitting.

This cure is mainly effective when the fault is a "hot" fault, i.e. misfiring and/or cutting out after some use then restarting when cold.

It's also a good preventive maintenance job to do before trouble starts!

[ThermalShark]

It used to be a hot problem, now it doesn't want to start at all. I'll try the suggested things and see if I can get the brick rolling again.

[ThermalShark]

So as I noticed that the price of a new ignition module wasn't very much, I changed it for a new unit and the car sputtered to life quicker than it ever has in the time I've owned it. Went on a test run too and had no stalls, also the engine seemed to run a lot smoother (previously it shook the entire car around on idle).

It was only a short test run but hopefully this fixed my problem. I will update this thread once I've driven it more to know for sure.

Lambda light is still on though and I still can't reset the codes.

[Laird Scooby]

Good news! Hope you used some thermal compound between the back of the new module and the body?

Disconnecting the battery for a while should clear the engine management light, if it comes back on after then maybe there's another problem but it sounds as if you've sorted it.

[ThermalShark]

Yes I did apply the thermal compound, it looked like some previous install didn't apply any of it when I took off the old one.

And I'll try the battery trick.

[Laird Scooby]

They tend to be very "sparing" in the factory when they fit them, i've known many that have little or no thermal compound on!
Also if they have already been renewed most mechanics either don't realise or know they should have heatsink compound on.

[TonyS9]

Yey! I'm putting this one on by bed post

The rev counter uses the back emf from the coil primary to drive it (not the namby pamby amplified 12V switching signal), so if you aren't getting rpm pulses there is not much else to go wrong on on the ignition side (computer, CPS and amp). These big coils rarely go (unlike new coil packs) and disti and plugs usually just get crappy and are the first thing people check normally.

[nutco]

Originally Posted by ThermalShark

So as I noticed that the price of a new ignition module wasn't very much, I changed it for a new unit and the car sputtered to life quicker than it ever has in the time I've owned it. Went on a test run too and had no stalls, also the engine seemed to run a lot smoother (previously it shook the entire car around on idle).

It was only a short test run but hopefully this fixed my problem. I will update this thread once I've driven it more to know for sure.

Lambda light is still on though and I still can't reset the codes.

Hi,
where did you get your new ignition module from, if I may ask how much was it,
Thanks

[ThermalShark]

Got it from my local parts store Motonet and it was 27€ roughly.