Help needed starting issue MG Zt diesel Mk2

mgzrjake · 16th February 2021, 09:23

Mgzt cdti auto. Mother went to start it and it turned over for fun, nothing. Remove fuel pipe running into top low pressure pump fuel arrives after a few cranks. Replaced it car starts drive it about park up and left for 30 minutes try again and it’s not starting just as before ? So what’s the issue fellow Zt diesel owners.

Thank you
Jt

Rick-sta · 16th February 2021, 10:37

Non starting on a diesel can be a few different things, but I always start with the basics checking the fuel pressures are ok. If you have toaf then fuel pressures are much easier to check.

How much fuel is there in the tank?

Assuming you have the 3 pump system (in tank pump, under bonnet low pressure pump next to the battery and high pressure pump) when the in tank pump fails and your fuel level drops below 1/4 mark it can struggle to start or run. Eventually once the fuel drops low enough it'll cut out completely and not start again.

If the fuel pressure from the in tank pump is fine then a weak under bonnet pump can cause starting and running issues. Giving the under bonnet pump a few taps with something metal can get it going again. Wonder if removing the fuel line from the under bonnet pump may have got it going again hence why it started.

mgzrjake · 16th February 2021, 12:26

Hi Rick the car has a full tank of fuel. Not sure on 3 pumps thought they had just 2 tank and in between battery and engine. This is where I removed fuel pipe from the back one, crank it and after a few moments fuel appears replaced it and it started 1st turn. 1/2 hour later back to square one cranking not starting.

bandayho · 16th February 2021, 13:09

starting problems can be a cam sensor, i just bought a new one and it all worked only paid £13.99 from ebay

MacRob · 16th February 2021, 23:35

Quote:

Originally Posted by mgzrjake

Hi Rick the car has a full tank of fuel. Not sure on 3 pumps thought they had just 2 tank and in between battery and engine. This is where I removed fuel pipe from the back one, crank it and after a few moments fuel appears replaced it and it started 1st turn. 1/2 hour later back to square one cranking not starting.

When the key is turned to position 2 the pumps should prime the system so fuel should be coming out of the line without cranking the engine. It sounds like either 1 of the pumps are failing(more likely to be the in tank pump) or there is a pressure leak or air blockage in the system. This could be in the fuel filter depending on how old it is and can be checked by simply removing the exit pipe from the filter and priming the system. If no blockage then the fuel should run out straight away. If it doesn't then the problem is in the filter and it needs changing.
Of cause I could be totally wrong about everything.

Mike Noc · 17th February 2021, 06:15

Yes fuel should start pumping around the LP circuit as soon as you turn the key to position 2, and should keep pumping for 30 seconds to 1 minute depending on which ECM is fitted, if you don't start the engine.

So there is a fault on the LP fuel delivery side.

16th February 2021, 09:23	#1
mgzrjake Loves to post MG ZTT 135+ diesel, MGZS 180 saloon MK2 Join Date: Mar 2016 Location: stockport Posts: 435 Thanks: 137 Thanked 72 Times in 53 Posts	Help needed starting issue MG Zt diesel Mk2 Mgzt cdti auto. Mother went to start it and it turned over for fun, nothing. Remove fuel pipe running into top low pressure pump fuel arrives after a few cranks. Replaced it car starts drive it about park up and left for 30 minutes try again and it’s not starting just as before ? So what’s the issue fellow Zt diesel owners. Thank you Jt

16th February 2021, 10:37	#2
Rick-sta This is my second home MG ZT 2.0 CDTI+ in Typhoon, MG TF 135 in Typhoon & Rover 75 Connoisseur CDTI SE in Pearl Black Join Date: Oct 2012 Location: Norfolk Posts: 7,532 Thanks: 2,718 Thanked 2,827 Times in 1,462 Posts	Non starting on a diesel can be a few different things, but I always start with the basics checking the fuel pressures are ok. If you have toaf then fuel pressures are much easier to check. How much fuel is there in the tank? Assuming you have the 3 pump system (in tank pump, under bonnet low pressure pump next to the battery and high pressure pump) when the in tank pump fails and your fuel level drops below 1/4 mark it can struggle to start or run. Eventually once the fuel drops low enough it'll cut out completely and not start again. If the fuel pressure from the in tank pump is fine then a weak under bonnet pump can cause starting and running issues. Giving the under bonnet pump a few taps with something metal can get it going again. Wonder if removing the fuel line from the under bonnet pump may have got it going again hence why it started. __________________ How to retrofit Cruise Control on a diesel with no OEM wiring in place: Link How to retrofit heated electric memory seats with no OEM wiring in place: Link How to operate FBH and ATC via text Link How to restore cloudy projector headlights Link

16th February 2021, 12:26	#3
mgzrjake Loves to post MG ZTT 135+ diesel, MGZS 180 saloon MK2 Join Date: Mar 2016 Location: stockport Posts: 435 Thanks: 137 Thanked 72 Times in 53 Posts	Re reply Hi Rick the car has a full tank of fuel. Not sure on 3 pumps thought they had just 2 tank and in between battery and engine. This is where I removed fuel pipe from the back one, crank it and after a few moments fuel appears replaced it and it started 1st turn. 1/2 hour later back to square one cranking not starting.

16th February 2021, 13:09	#4
bandayho Newbie rover 75 Join Date: Dec 2018 Location: Hythe Posts: 7 Thanks: 0 Thanked 2 Times in 1 Post	had a similar issue starting problems can be a cam sensor, i just bought a new one and it all worked only paid £13.99 from ebay

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17th February 2021, 06:15	#6
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,547 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	Yes fuel should start pumping around the LP circuit as soon as you turn the key to position 2, and should keep pumping for 30 seconds to 1 minute depending on which ECM is fitted, if you don't start the engine. So there is a fault on the LP fuel delivery side.