Help, car won't start...

[amwebby]

Thanks Ollie. You deserve a rest, what a fabulous day. I'll update everyone tomorrow.

 

[mikevernon]

Amwebby. Don't even think about replacing the crank sensor (or any other parts), no matter what anybody on here tells you, until you have carried out some simple basic tests.
Firstly check for a spark at the plugs. If you have a spark then your ignition system is almost certainly fine, including the crank sensor, and the problem is problem is likely to be on the fuel side.
Assuming you have a spark, check for fuel pressure by simply undoing a union in the fuel line. If your fuel pump has been working you will have residual pressure in the system and fuel will squirt out when you loosen the union. If it doesn't, try cranking the engine with the union loose. No fuel means your pump isn't running, in which case the next step is to check whether the pump is receiving power from the fuel pump relay.
Simple, methodical checks will save you a lot of time and money.

 

[television]

Amwebby. Don't even think about replacing the crank sensor (or any other parts), no matter what anybody on here tells you, until you have carried out some simple basic tests.
Firstly check for a spark at the plugs. If you have a spark then your ignition system is almost certainly fine, including the crank sensor, and the problem is problem is likely to be on the fuel side.
Assuming you have a spark, check for fuel pressure by simply undoing a union in the fuel line. If your fuel pump has been working you will have residual pressure in the system and fuel will squirt out when you loosen the union. If it doesn't, try cranking the engine with the union loose. No fuel means your pump isn't running, in which case the next step is to check whether the pump is receiving power from the fuel pump relay.
Simple, methodical checks will save you a lot of time and money.

On cars of this vintage and many much older we have never had a fuel pump problem. CPS ? well thats another story as there are hundreds of post on this, sure we could be wrong, its simple to measure and Amwebby has a meter,, should be 1k Ω if OK

 

[amwebby]

Not being too mechanically knowledgeable with MBs I think I'll let the MobiloLife guy diagnose the problem, and hopefully fix it. Thanks to Malcolm, Ollie and Mike for the pointers, at least I'll have some idea what the Mobilo guy is talking about!

 

[amwebby]

Update 11:30 am 19 May 2008. The Mobilo man came this morning, spent a long time looking at the problem. STAR was showing it as not receiving a start signal. He has narrowed it down to the crank sensor and is just off to the local dealer to get the part. I'll update once he's fitted that.

 

[BlackC55]

I have just fitted one this morning.

Such a common problem.

 

[amwebby]

Thanks Ollie. This is the second time you have diagnosed a problem correctly based on experience. MB technicians seem to follow a procedure that brings them to the same point but at a much higher cost in terms of labour. Unlike some I don't believe this is designed to extract money, it is just a failure to harvest the knowledge that must exist in their own workforce.

 

[amwebby]

Update: 12:40 New crank sensor fitted. Problem sorted. Unfortunately the cost of the part is £87 not £47, which I assume Mobilio will charge me for.

 

[television]

Update: 12:40 New crank sensor fitted. Problem sorted. Unfortunately the cost of the part is £87 not £47, which I assume Mobilio will charge me for.

£47 from Bosch and £87 from MB and this is what I have always said, for months now, it has the MB number £87 one side, and the Bosch £47 number on the other.

 

[BlackC55]

Glad it is sorted.

The non-Bosch CPS don't tend to fail.....

 

[robert.saunders]

Glad it's sorted - well done guys for a correct diagnosis, as usual

 

[amwebby]

Glad it is sorted.

The non-Bosch CPS don't tend to fail.....

I have the old one in my hand. It is marked Bosch one side and MB the other...

The annoying thing is, the local dealer having spent six hours or more tracking down and allegedly sorting a drain on the battery, the battery itself is still showing an inability to hold a charge, dropping to 10.6 after less than a dozen attempts to start the car.

 

[BlackC55]

How old is the battery?

What is the charging voltage?

 

[television]

Do not forget that STAR can pull loads from the battery, and you cant measure anything without it being fully charged first

 

[Howard]

You guys are so clever !

 

[amwebby]

Do not forget that STAR can pull loads from the battery, and you cant measure anything without it being fully charged first

That was what first alerted him. He had his STAR hooked up and it was throwing all sorts of errors because the battery was low.

I'm going to monitor it over the next few days.

 

[BlackC55]

Those battery errors can usually be ignored especially after the recent drain problem you had.

 

[amwebby]

Thanks Ollie. The battery is only a year old. I'm guessing it is fine and too many start attempts and being hooked up to STAR while not running have drained it.

 

[television]

Thanks Ollie. The battery is only a year old. I'm guessing it is fine and too many start attempts and being hooked up to STAR while not running have drained it.

Just for the record on a similar type of car, mine has been used a lot of late, but on Saturday I though I would give it its monthly top up, it took 4 amps for 6 hours, and I took it off charge after 8 hours when it was down to 2 amps