V6 Won't Start - Help - Page 4

wutang · 15th April 2012, 09:47

i would replace the crank sensor, if faulty the engine will turn over but as the ecu cant work out where in the cycle it is it wont allow any fuel flow. (into the cylinders should still be pressure at the rail.)

as pictured above there is a little valve near the throttle body, looks like a tyre valve, push in the middle pin with ignition on and fuel should come out.

Richard

Imm75 · 15th April 2012, 09:51

Apologies, my info on the temp sensor was for a V6, I just saw you have a diesel.

SD1too · 15th April 2012, 09:54

Quote:

Originally Posted by Imm75

I read somewhere that if the temp sensor reads wrong, the ecu goes into predetermined mode but if grounding to earth then will prevent the car from starting.

MG Rover says that the engine management substitiutes a default value reflecting a "part warm" condition to enable the engine to run. The cooling fan will run at fast speed when the ignition is switched on. It also says that the temperature gauge will display 'cold' and the temperature warning light will illuminate.

Stop Press: MG Rover also says that the V6 will not start if the "sensor earth is short circuit to 12 or 5 volts". That's a bit gobbledegook but seems to confirm what Imm75 remembered.

Simon.

SD1too · 15th April 2012, 09:55

Quote:

Originally Posted by Imm75

Apologies, my info on the temp sensor was for a V6, I just saw you have a diesel.

No, it's very confusing. He has a diesel, but he's just bought a V6 as well but not put it in his profile. I fell for that one too! Grrrr.

Simon.

MangoMan · 15th April 2012, 10:14

This is the last time I'm going to say this, and I'll eat my hat if I'm wrong, but wouldn't it be worth just putting in some more petrol to read just over 1/4 tank??? Whether you use it now or later, you will use it anyway........

If I'm wrong, I apologise. But if it was me, (which I know it isn't) it would be one of the first things I would do as it would elliminate that idea.

Jakg · 15th April 2012, 12:31

Quote:

Originally Posted by Imm75

Apologies, my info on the temp sensor was for a V6, I just saw you have a diesel.

To make this clear (and I apologize for not doing it before!), my car is a 2004 MG ZT CDTi. However, I've also bought a 2000 Rover 75 2.5 V6 to break, which I bought as a non-runner due to this fault. It would be nice to be able to get the car running to move it around the garden, and to be able to sell the engine

Quote:

Originally Posted by SD1too

No, it's very confusing. He has a diesel, but he's just bought a V6 as well but not put it in his profile. I fell for that one too! Grrrr.

Simon.

Sorry, I know this is annoying!

I don't really class the 75 as "mine" as soon it'll be broken, crushed and cubed and on it's way to the scrapyard in the sky!

Quote:

Originally Posted by SD1too

If test 7.0 displays 128, that means the coolant temperature is 12.8 degrees.

Simon.

I don't think so - my diesel will show 076, meaning 76 degrees... the ambient sensor is accurate to xx.0 or xx.5, but the coolant temp is to the nearest degree.

Either that or the hottest I've ever got my diesel was 9.8 degrees!

Quote:

Originally Posted by MangoMan

This is the last time I'm going to say this, and I'll eat my hat if I'm wrong, but wouldn't it be worth just putting in some more petrol to read just over 1/4 tank??? Whether you use it now or later, you will use it anyway........

Because I'm breaking the car, any fuel I put in is effectively "wasted" - plus, nobody in my house owns a petrol car (all diesel) so we have ~5L of petrol, but it's for the lawnmower... and getting more petrol involves driving 7 miles to the nearest town!

But it's one thing I may have to try soon...

wutang · 15th April 2012, 13:21

on my v6 i have run it for 35 miles with the range computer saying 0 miles and got over 64 litres in it at fill up so the v6 will run with fumes in the tank.

David3807 · 15th April 2012, 15:25

Quote:

Originally Posted by MangoMan

This is the last time I'm going to say this, and I'll eat my hat if I'm wrong, but wouldn't it be worth just putting in some more petrol to read just over 1/4 tank??? Whether you use it now or later, you will use it anyway........

If I'm wrong, I apologise. But if it was me, (which I know it isn't) it would be one of the first things I would do as it would elliminate that idea.

Agree with all that. Worth a try even if it just eliminates one possibility

chrissyboy · 15th April 2012, 16:27

i agree basic diagnosticsd is to see if you have fuel ,spark ,compression,if all are present the car will start . dont forget the fuel gauge can give false readings ,so it might not any fuel at al in the tank .i would put some fuel in just to rule a fuel issue out .them using an inline spark plug check for spark at plugs ,lso when turning engine over does it sound ike it has loads of compression. it may also be the belt has broken so engine not being turned over . have a look a the pulleys when someone turns the key to see if they turn ..can also e that the belt has slipped a tooth or two so timing is out so no fuel being supplied

SD1too · 15th April 2012, 16:40

Quote:

Originally Posted by Jakg

I don't think so - my diesel will show 076, meaning 76 degrees... the ambient sensor is accurate to xx.0 or xx.5, but the coolant temp is to the nearest degree.

I've just tried it in my car and you're right. An error seems to have crept into the information I copied from this forum a while ago.

Simon.

15th April 2012, 10:14	#35
MangoMan This is my second home Looking.... Join Date: Oct 2010 Location: England Posts: 10,911 Thanks: 862 Thanked 1,111 Times in 868 Posts	This is the last time I'm going to say this, and I'll eat my hat if I'm wrong, but wouldn't it be worth just putting in some more petrol to read just over 1/4 tank??? Whether you use it now or later, you will use it anyway........ If I'm wrong, I apologise. But if it was me, (which I know it isn't) it would be one of the first things I would do as it would elliminate that idea. __________________ *Regards, Bill - (MangoMan).* (Member 00854) http://i1110.photobucket.com/albums/...d.jpg~original

15th April 2012, 16:27	#39
chrissyboy This is my second home lovely little ford focus. Join Date: Jul 2009 Location: East Dulwich Posts: 7,877 Thanks: 2 Thanked 82 Times in 68 Posts	i agree basic diagnosticsd is to see if you have fuel ,spark ,compression,if all are present the car will start . dont forget the fuel gauge can give false readings ,so it might not any fuel at al in the tank .i would put some fuel in just to rule a fuel issue out .them using an inline spark plug check for spark at plugs ,lso when turning engine over does it sound ike it has loads of compression. it may also be the belt has broken so engine not being turned over . have a look a the pulleys when someone turns the key to see if they turn ..can also e that the belt has slipped a tooth or two so timing is out so no fuel being supplied __________________ [ I'm really confused. -I keep dreaming I'm an insomniac Last edited by chrissyboy; 15th April 2012 at 16:45..

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15th April 2012, 09:47	#31
wutang Posted a thing or two Rover 75 2.5 auto (LPG) & mg tf 160 Join Date: Nov 2006 Location: Dartford Posts: 1,124 Thanks: 5 Thanked 39 Times in 36 Posts	i would replace the crank sensor, if faulty the engine will turn over but as the ecu cant work out where in the cycle it is it wont allow any fuel flow. (into the cylinders should still be pressure at the rail.) as pictured above there is a little valve near the throttle body, looks like a tyre valve, push in the middle pin with ignition on and fuel should come out. Richard

15th April 2012, 09:51	#32
Imm75 Regular poster Rover 75 Saloon Join Date: Apr 2012 Location: London Posts: 69 Thanks: 1 Thanked 7 Times in 3 Posts	Apologies, my info on the temp sensor was for a V6, I just saw you have a diesel.

15th April 2012, 13:21	#37
wutang Posted a thing or two Rover 75 2.5 auto (LPG) & mg tf 160 Join Date: Nov 2006 Location: Dartford Posts: 1,124 Thanks: 5 Thanked 39 Times in 36 Posts	on my v6 i have run it for 35 miles with the range computer saying 0 miles and got over 64 litres in it at fill up so the v6 will run with fumes in the tank.