w126 560sec starting up issue

[grober]

Could be several things but ironically your poor starting could be caused by the mixture being too rich. This could be a failure of the thermo -time switch which effectively earths the cold start valve- meaning it doesn't operate normally when the engine is hot. OR it could be a failure of the warm up regulator which controls the mixture strength to the engine depending on engine temperature [ its bolted to the cylinder head] Both units incorporate bimetal springs and in the case of the regulator a flexible diaphram- these units are very robust and reliable but inevitably with time------?? I suggest you go for a run to really heat up the engine and clean up the plugs then when you experience the hot start problem remove a couple of plugs and check for fuel- if they stink of fuel its a mixture/enrichment problem if they are "dry" then fuel supply problem [ FPR etc] Bosch K Jetronic Fuel Injection Manual

 

[arfan786]

ok guys i got hold of anther fuel pump relay from another 560 sec and the car worked fine took it for a drive to the petrol station a few miles away and engine was well warmed up. Anyway i filled the car up and went to start it again didn't fire up straight away and I had the same problem again then waited a bit on the 3rd time it fired up drove home parked up switched engine off and started it again and it wouldn't start up again?:fail

I was convinced it was a relay but of i bridge it the car fires up fine every time
?

 

[arfan786]

car is with howard williams and now doesn't want to start up at all not even from cold??

we suspect it is the ignition coil as i have tried a new FPR and that hasn't worked either.

any ideas???

 

[Skhan]

I was just going to ask if you had sorted it, I had the same problem with my 320 ce last week, had issues firing up & then just wouldn't fire up at all. Turned out to be the crank shaft sensor... Give that a go

 

[arfan786]

tried new ignition coil and that hasn't cured the problem on the car. this is really annoying me as i want the car out of the garage. is there some sort diagnostic tool for these cars which could source the problem?

 

[neilrr]

Any good MB indie should be able to get to the bottom of this without throwing parts at the car.

It's not rocket science - it's either fuel or spark not getting to where it needs to be to start the car.

 

[John Jones Jr]

the part number is 0035452505 thats the number stamped on top of relay

€35-40 on eBay.de, but may not be your problem.

The first part I'd change regardless is the OVP replay as already mentioned, required or not it's wise preventive maintenance especially if it's the original. I'm presuming basic items like fuel filter, leads, dizzy cap & rotor etc are all in good order. If so, it might be well worth getting the KE system checked out.

 

[arfan786]

i am thinking whether it could be the OVP relay? i just want the car started and out of there.

 

[neilrr]

Well really, it could be any number of things. Can't howard williams do any better than guess?

 

[arfan786]

that's what i am beginning to think? plus he is busy with other jobs etc. thats why i want the car out of there really as its been there for 2 weeks now.

 

[neilrr]

Haven't used these guys myself but they have a good rep. Bought a 2.5-16 a few years ago that had been looked after by them & it was spot on.

They're about 5-6 miles away from where your car is now.

Andy Gayle MB Services Ltd (Smethwick,UKG)

 

[arfan786]

yeah i am thinking trying somewhere else as they have taken 2 weeks and nothing really been achieved.

whats andy gayle like with old classics?

 

[Dieselman]

Andy has been a Mercedes mechanic for a long time, both Indie and at dealers before that.

 

[arfan786]

tried andy gale but don't he wants to get involved etc. appears none of the indies want to touch an sec that doesn't start.

however the advice i have been getting that it could be the ignition module.

but do i spend money changing that or get a definite diagnosis??

 

[jjrodger]

My independent, Phil Baister of Staithes Garage, Gateshead, had a 560 in recently with the same problem and after trying everything else it was resolved with a new ignition control module purchased at huge expense. You may wish to give him a call, he's very helpful and I am sure he would spare five minutes of his time to talk it through with you. The number turns up on a Google search, I don't have it immediately to hand.

 

[arfan786]

I reckon it is ignition control module personally. I have been reading about all the symptoms as well.

 

[arfan786]

anyone have ezl module? are they interchangeable? my part number is 0065455432

thanks

 

[neilrr]

I have one.

Make sure it's what you need before you buy one, whether it's from me or someone else.

 

[bmthnick1981]

Having similar problems with my 560 SEC so following this thread with interest, any update?

 

[Skhan]

Having similar problems with my 560 SEC so following this thread with interest, any update?

OP sorted his by replacing the ignition control module