E320 W124 Estate not starting

[tonyhtb]

Hello all,

One dead W124 estate sitting in the garage. My trusted mechanic replaced the fuel pressure relay and now we have fuel in the rail, however no spark or fuel in the cylinder head ( dry plugs). He suggested a crank sensor or and this sounds bad an ECU issue.

Now has anyone else had a similar problem like this? Where are the aforementioned crank sensors located? ECU sounds expensive is this correct? Is there any way to test/refurbish said ECU.

Any help would be gratefully received as other than this its a cracking car without the usual corrosion problems.

 

[AMG19]

It could be a few things. I wouldn't go down the road of replacing things without letting a specialist have a look at it. My indi has loads of slave parts for 124s so can normally swap parts without having to purchase them and charge you. That way you only pay for the part that fixs the problem.
Whats your location?

 

[BlackC55]

Have a look at the engine wiring loom. Open it up where it goes through the spark plug cover.

 

[tonyhtb]

Thanks for the location of the cps, I am based in the New Forest Hampshire, theres a higher than average concentration of w124's down here as they're (usually!!) so reliable!

 

[Martyn_n]

Don't go plugging in ecu's just to rule it out, it could be that the loom has fried yours and would think nothing of taking out another.

 

[Martyn_n]

Have a look at the engine wiring loom. Open it up where it goes through the spark plug cover.

And, as you have dry plugs, at the injector plug couplers. The easiest way of knowing is to look at the plug coupler wiring on the camshaft solenoid, if that is perished the ones in the cam cover valley will definitely be shot.

 

[tonyhtb]

Hi Martyn,

Loom was replaced 3 years ago so it doesn't really point to that,thing thats making my guy scratch his head is the no spark or fuel! This is why he suggested the cps or ecu.

 

[Martyn_n]

Hi Martyn,

Loom was replaced 3 years ago so it doesn't really point to that,thing thats making my guy scratch his head is the no spark or fuel! This is why he suggested the cps or ecu.

When I replaced my loom the connector to the CPS (I think it was that, N/S/R of engine) was a pig to push back on, I worry all the time it will pop off again. Maybe worth looking to see if it is secure.

 

[AMG19]

Crank sensors tend not to go wrong on this engine so it is unlikely to be the problem. It could well be just a voltage protection relay - a more common and likely problem.

 

[kth286]

so the engine is turning over ok ?

Then look at the Over voltage protection relay OR the fuses first, as this muggy weather causes corroded fuses to show their weakness.

Turn the fuses in their holders initially and then try start car.

 

[GP801]

Certainly could be the OVP relay ( the one behind the battery). Its involved in lots of functions including the fuel pump. The ECU is very expensive - had to do ours earlier in the year. Part alone £1400. You dont want to be changing that unless you really know its shot. You really need a specialist. If you have a recovery service use it to get it moved to a specialist. PCS in Horndean or Startech in Poole spring to mind.

 

[tonyhtb]

Thanks ever so much everyone for all of the helpful advice. I think I need to get my mechanic to replace the OVP relay and will post on the results.

 

[neilrr]

Is your mechanic an MB specialist?

 

[tonyhtb]

No but he is very good works on all my cars. Anyone know the part number for the ovp relay?

 

[neilrr]

You need to go to a specialist MB indy who has the diagnostic equipment to find out what's wrong with your car. Otherwise you will waste hundreds of ££££s fitting parts you don't need to replace.

Where are you located?

 

[tonyhtb]

Brockenhurst in the New Forest