Hi all

I have spent hours searching but haven't found everything in one place so I'm trying to stitch bits together. 2004 K74 Classic Diesel Turbo

Before head gasket swap everything was OK (apart form the obvious) It started fine, ran fine, no issues other than getting gas in the water.

Now I can't get it to start straight after head gasket swap. Timing belts double checked, back in the right place on crank and cam and on injector pump. Not a tooth out or worse. Brand new NGK glow plugs and the bar does go to 12v positive when the glow plug dash light is on. I've checked all the sensor connections on the injector pump and all readings are OK (fuel temp sensor did catch me out until I saw it was kiloohms rather than ohms). I've cracked open an injector fitting and primed the fuel at the filter. Pump goes hard. When I turn it over (fully charged battery, cranking nice and fast) I get nothing coming out of the fuel pipe. Nada. After cranking, the filter pump is still hard. I checked the terminal on the stop solenoid and with ignition on, it does not get +12V so I guess that is wrong? Can anyone please confirm when should the stop solenoid terminal be at +12V

So I'm now thinking 2 things - either the stop solenoid or the crank sensor (hence why the stop solenoid does not get +12V ?). I'm off out to get a 22mm spanner to remove the stop solenoid, but is there any way to test the crank sensor without the engine running? Any other possibilities please?

Thanks very much

engine fuse or engine relay does the engine light come on with the ignition then go out

Hi
Both the big fuses by the battery seem good, all dashboard lights are working 'normally' I think. EML and ABS lights not on permanently. Glow plugs light goes on and off as normal. I checked for error codes and I am only getting 51 (removed EGR). (Codes on ABS but they have been there since we got the truck)

I switched out the blue relay D marked Engine in the relay block by the battery. It was a Blue one marked MR524999. I switched it with a generic relay. Is that the one you mean?

so When you take an injector pipe off and leave it off do you have no fuel coming out at all when cranking??

Quick check for the solenoid is to put 12v to it Off the battery and leave it connected while you start it

Ah, good idea. I'll try that.

Yes, I have no fuel at all coming out of the disconnected injector pipe while cranking.

Definitely sounds like a fuel issue then. The solenoid needs a constant 12v to keep it open. If the crank sensor was bad then surely it would throw the EML up

Superb!

I put a wire across from Battery + to the Stop Solenoid terminal. Makes a click every time it was connected and disconnected so that was good. I did that quite a few times. Left it connected and tried to turn it over. Bingo, this time we have fuel and a few coughs. Reconnected the fuel line and it started. Excellent. So now I have disconnected my little wire and everything seems OK so maybe it was just connecting and disconnecting a few times which has woken the solenoid up again?

Thank you very much!!

So what to do with the solenoid? If I take it out, can I clean it up and put it back, or should it be replaced?


Now to fix the oil leaking down the back of the block. Presumably, from the half moon seal.

And why was I not getting +12v on the solenoid with ignition on previously? Does it only stay at +12v for a few seconds? Or does it only stay +12v while cranking and running?

It should stay on +12v all the time the ignition is on. It sounds more like a loose connection somewhere. If the solenoid is now working, don't try to fix it - you'll more than likely knock some crud into the injector pump.

I found the leak at the back. It was the oil feed pipe to the turbo, so just nipped it up a bit more.

Thanks

happy days weird one

Good to hear it’s all running fine. I imagine the solenoid will run off a relay. Relays do stick from time to time. Or as heathen suggested a loose wire. At least you now know where to start if u ever get a starting problem.