[Lee white]

Afternoon all, I 'm new to the site but am hoping someone can help me with a nightmare I'm having at the moment.

I've got a 54 plate 1.3 corsa c diesel. It's always been a bit of a pig to start up when cold but recently after changing the alternator ( the old one's bearings went) randomly the car now won't start unless I spend a good 5min cranking it at which point it splutters into life and runs sweet as a nut?!?

I noticed that the glow plug light only comes on for literally 1 second so took the glow plugs out to see if they were functioning, I had a friend turn the ignition while I carefully held the plug with no joy. Our wired the plug up to the battery using jump leads, earth on the body live on the tip an instantly the plug worked. I then ran a test bulb, earth to the battery and live to the plug lead to see if I could see power at the lead end, no joy, no power!

Thinking the relay must have gone I've just spent the last hour changing it for a new relay, to my supreme it's made no difference, car still won't start without a fight and the glow plug light only comes on for 1 second still.

Anyone got any ideas? Does the coolant temp sensor drive an input into the ecu for cold starting? By that I mean if the sensor is faulty would it stop the glow plugs from heating due to a false input or something? (As you can see I'm grasping at straws!)

All help is much appreciated!
Thanks
Lee

 

[g4vvq1983]

Hi Lee....ok here we go, the relay should have 2 thick wires and a number of thin ones, now one of the thick ones goes to the heater plugs and the other thick one is live from the battery or where ever it goes...so you want to make sure one of those thick wires is live all the time...if not look at fused links etc, would be about 60 amps plus....the fact the light just flashes quick is telling you the system is prob working but the glow plugs are not required because the temp isn't cold enough for them to come on, they only work around 0 degrees centigrade or below....and yes i think the water temp sender somehow is linked to the relay.....

My feeling is your starting problem has nothing to do with the heater plugs, i have know an electric fuel pump in the tank not to work and you have to crank it over for ever to start it, but i'm not sure that car has a fuel pump on, i think it a common rail system and the high pressure pump sucks the fuel up, so there might be a problem with that....

The other thing that comes to mind is, it prob has a crank sensor on which triggers the injectors via the ECU....so that sensor could be naft, i suppose it would be a good idea to do a code test on it, might come up with something..you cant do a pedal test on a diesel i am told....well few ideas for you to ponder, its not low on compression is it? that can cause it not to start, there a compression ignition engine a diesel....no compression no ignition lol...it would still run ok once it was started...Fred in Essex.

Afternoon all, I 'm new to the site but am hoping someone can help me with a nightmare I'm having at the moment.

I've got a 54 plate 1.3 corsa c diesel. It's always been a bit of a pig to start up when cold but recently after changing the alternator ( the old one's bearings went) randomly the car now won't start unless I spend a good 5min cranking it at which point it splutters into life and runs sweet as a nut?!?

I noticed that the glow plug light only comes on for literally 1 second so took the glow plugs out to see if they were functioning, I had a friend turn the ignition while I carefully held the plug with no joy. Our wired the plug up to the battery using jump leads, earth on the body live on the tip an instantly the plug worked. I then ran a test bulb, earth to the battery and live to the plug lead to see if I could see power at the lead end, no joy, no power!

Thinking the relay must have gone I've just spent the last hour changing it for a new relay, to my supreme it's made no difference, car still won't start without a fight and the glow plug light only comes on for 1 second still.

Anyone got any ideas? Does the coolant temp sensor drive an input into the ecu for cold starting? By that I mean if the sensor is faulty would it stop the glow plugs from heating due to a false input or something? (As you can see I'm grasping at straws!)

All help is much appreciated!
Thanks
Lee

 

[Lee white]

Changed the water temp sensor today (awkward little job) made no difference though. I've sat and listened to the in tank pump, it cycles for around 20 seconds before shutting off. I've tried to wait for the pump to hit pressure and stop before actually attempting to start the engine, no joy there either.

It's worth mentioning that during the attempt to start the car I get quite a bit of white smoke out the back, it soon clears once the motor finally springs into life.

Once the car does start it runs really sweet, very smooth and quiet.

 

[g4vvq1983]

Well white smoke can mean steam, head gasket etc, or too much fuel, i'm glad you actually proved there is a fuel pump on it, yes the diesel pumps do run a long time for some reason, the petrol ones run about 2 seconds, i would disconnect the delivery pipe under the bonnet and turn ignition on see if fuel actually comes out, i supposed it isn't a blocked fuel filter, if its any help the primary fuel pressure is about 40 to 60 pounds psi, and the secondary is incredibly high, about 20 thousand pounds psi, if that white smoke is fuel it sounds to me like low compression's, does it start ok when it hot?.

I think the compression pressure should be around say 400 pounds psi, if its about 200 or below it prob wont start...that's ok for a petrol but not diesel...the compression ration on a diesel is about 25 to 1, a petrol is about 10 to 1....so not sure where all that leaves, can you get the compression's tested.....if your cleaver you can calculate it with an amp meter on the battery lead...if it only uses about 100 amp cranking you have low compression's...prob not much help but i tried lol....Fred in Essex.

Changed the water temp sensor today (awkward little job) made no difference though. I've sat and listened to the in tank pump, it cycles for around 20 seconds before shutting off. I've tried to wait for the pump to hit pressure and stop before actually attempting to start the engine, no joy there either.

It's worth mentioning that during the attempt to start the car I get quite a bit of white smoke out the back, it soon clears once the motor finally springs into life.

Once the car does start it runs really sweet, very smooth and quiet.

 

[Lee white]

Well white smoke can mean steam, head gasket etc, or too much fuel, i'm glad you actually proved there is a fuel pump on it, yes the diesel pumps do run a long time for some reason, the petrol ones run about 2 seconds, i would disconnect the delivery pipe under the bonnet and turn ignition on see if fuel actually comes out, i supposed it isn't a blocked fuel filter, if its any help the primary fuel pressure is about 40 to 60 pounds psi, and the secondary is incredibly high, about 20 thousand pounds psi, if that white smoke is fuel it sounds to me like low compression's, does it start ok when it hot?.

I think the compression pressure should be around say 400 pounds psi, if its about 200 or below it prob wont start...that's ok for a petrol but not diesel...the compression ration on a diesel is about 25 to 1, a petrol is about 10 to 1....so not sure where all that leaves, can you get the compression's tested.....if your cleaver you can calculate it with an amp meter on the battery lead...if it only uses about 100 amp cranking you have low compression's...prob not much help but i tried lol....Fred in Essex.

car starts great when warm, just after you've left it for over an hour or so
I've just bought a corsa d 18kw starter for £20, apparently the original starter has been found to be the issue on some corsa diesels as it wasn't up to spinning the dual mass flywheel fast enough? Thought for 20 quid I'd give it a try, bet it's a swine to fit though, everything else has been so far! 😂 thanks for the advise so far!