W124 wont start.

[Merryhill]

My W124 220 won't start. I noticed the indicators no longer blink when I use fob to open/close the vehicle, although the small red/green ones on door handle/boot do. The indicators do work otherwise.
When I try to start the vehicle, the engine turns, but does not start. Could this be linked to the indicators no longer blinking when the key fob is used? I'm not sure how investigate this, so any advice greatly received.

 

[grober]

You probably have an after market alarm fitted which has gone faulty.the control unit is usually hidden deep behind the dash / the alarm sounder under the wing wheel arch liner - it normally breaks the fuel pump relay / overvoltage relay or starter motor circuitry via its own relays preventing the car from starting. each fitment is slightly different but a good vehicle electrician should be able to fix it by reinstating the cars original circuitry after removing the alarm or fitting a new one

 

[Merryhill]

Thanks Grober. I did have an alarm fitted about 3 years ago, but I got the same installers to disarm it several months ago. It's been fine up to this point.

 

[grober]

then you may have a problem with the fuel pump relay or OVP relay or their original wiring- do you hear the Fuel pump run on ignition switch on?

 

[Gbrowncls55]

Crankshaft position sensor perhaps.

 

[Merryhill]

I appreciate the suggestions. I can't hear the fuel pump prior to engine turning over. The fuses all appear OK, not sure about the relays8

 

[optimusprime]

I would ask your alarm guy to visit you again and remove the alarm all together ..if it is not working its still connected to vital items in the car .

 

[Merryhill]

It seems strange it's suddenly stopped, out of the blue. Maybe when I disconnected the battery to put it on charge it triggered something? I think it's a job for a professional!

 

[optimusprime]

You did not put the battery on the wrong way about did you ?

 

[Bellow]

If you are confident at removing a spark plug, perform old school diagnostics.

Crank engine as if attempting to start it.
Remove a spark plug (choose one where the lead allows you to earth the plug) and note whether there is a smell of petrol.
Robustly earth the spark plug (preferably clamped with vice grips, croc clip on jumper lead, etc) where it can be seen when you crank the engine on the key. If spark is present, not an ignition problem. If no spark and smell of petrol present assume ignition problem.
If spark is present and no smell/sign of petrol assume fuelling problem and pursue immobiliser/relay as source of problem.
The above doesn't guarantee finding the problem but at least gets the ball rolling.

 

[Merryhill]

Thanks all for the suggestions. I'll spend some time over the weekend exploring further.