W638 V280 - 1998 - Starting Problems

[SimonMultiMercs]

hi. my RHD V280 developed a fault which would send the idle speed all over the show. However it will now not even start. I have replaced the coil pack, HT leads, and spark plugs. It still wont start. it smells as if fuel is getting through. I have had a spark plug on the new leads but cant get a spark

would the immobilser create this scenario ? (can this be disabled / removed ?)

There is very early round diagnosis plug socket under the passenger seta, does anyone know if a specifi ODB reader would work on this ?

I have checked all fuses and tried a ohms test on some relays

does anyone have a wiring diagram / workshop manual / disc ??

hope someone can help
simon

 

[carat 3.6]

I'm fairly sure you have the VW vr6 engine in your van, but it will use the Mercedes 38 pin diagnostic plug for OBD1.

I'd pull out the fuel pump relay while your doing fault finding so you dont drown it in fuel, try to get a diagnostic reader hooked up with the mercedes adapter and check if you have a crank signal.

 

[SimonMultiMercs]

carat, many thanks for your quick response. Its true, it is the 2.8 ltr VW engine.
I have attached a picture of the socket that is under the seat.
I realise that you can get odb plugs with old style merc plugs on, but not all readers can read this old of a vehicle (so i am led to believe)
I was hoping someone had experiance of which particular extact model of reader would work on this vehicle ? - icar, autel, etc ...
good call with fuel relay

 

[carat 3.6]

I use an autel for most things, it reads the older models but will be limited to the engine electrics for obd1.

 

[SimonMultiMercs]

UPDATE - I managed to source a crank shaft sensor off a big river shopping web site, but postage was from China, so I had to wait. I fitted the new sensor and the V280 fired up after a couple of turns. So success at getting the engine running again. However, while idling, the original problem of rev's jumping from circa 800 to 1200 / 1300 rpm re-appeared. I punch the throttle down thinking it may be "choke" related but no luck. I am going to try the o2 lambda sensor next, and just awaiting delivery.

I do have a little niggle that it could be temperature related but I have already replaced the coolant temp sensor, however the wire feeding the plug was very very fragile, so I think i'll be re-checking my work if lambda sensor doesn't work

Just to note, there is only 1 sensor on the exhaust of the V280

any and all advice welcomed