Possible injector fault

jc82 · 3rd January 2021, 12:54

Hello all.

2003 MG ZT-T+ CDT

I've just acquired the above car and am so far very happy with it. It's not perfect with a few bits of interior trim needing re-attached and I've already discovered the absolute joy of changing knackered projection headlamp bulbs!

One issue that's bugging me slightly and one I hope someone can help with is it's not a great starter. It turns over as normal and then gets quicker as if the fuel pressure is building up before it starts. Once going it idles sweetly and performs perfectly. It had a new battery and starter motor fitted just before I bought it and it does start better from cold. I'm assuming I can rule out a faulty preheat system with this being the case. I've changed the diesel filter and added a diesel cleaner, so far with very little improvement.

One thing I did notice whilst idling is that if I put my hands on the injector pipes, no.2 injector does not feels as strong as the other 3. Admittedly it is a pretty Heath Robinson way of checking something but usually the simplest tests are the best. Would it be worth performing a leak-off test on the injectors before carrying anything else out such as cam/crank/coolant sensor checks?

Any help is much appreciated.

TIA
John

AndyN01 · 3rd January 2021, 13:35

Hi John and welcome along.

My first thought was to get a full T4 diagnostics check but in the present situation that isn't so easy coupled with the fact that folks with a T4 are a fair distance from you.

My diesel and previous Rover 75/MG ZT diesels that I've owned have fired up pretty much straight away so it sounds like something is amiss.

New battery & starter motor pretty much rules that line of enquiry out.

If you can do a leak back test then that'll certainly move things forwards.

There's several threads on here about actually doing one. A search will get you everything you need to know.

Try a squirt of easy start and see if that helps. If it fires up instantly then that points to a lack of diesel/pressure for starting. Possibly a duff injector which the leak back test should confirm. Or possibly a duff pump not giving enough pressure? Or possibly a leaking "O" ring on the high pressure fuel regulator?

One suggestion, and apologies if I'm teaching granny to suck eggs - check things one at time. It's very easy to get carried away and then be lost as to what it was that actually sorted it out.

I'm sure some of the more knowledgeable guru's on here will be along shortly with more detailed and specific advice.

Good Luck

COLVERT · 4th January 2021, 20:38

Quote:

Originally Posted by jc82

Hello all.

2003 MG ZT-T+ CDT

I've just acquired the above car and am so far very happy with it. It's not perfect with a few bits of interior trim needing re-attached and I've already discovered the absolute joy of changing knackered projection headlamp bulbs!

One issue that's bugging me slightly and one I hope someone can help with is it's not a great starter. It turns over as normal and then gets quicker as if the fuel pressure is building up before it starts. Once going it idles sweetly and performs perfectly. It had a new battery and starter motor fitted just before I bought it and it does start better from cold. I'm assuming I can rule out a faulty preheat system with this being the case. I've changed the diesel filter and added a diesel cleaner, so far with very little improvement.

One thing I did notice whilst idling is that if I put my hands on the injector pipes, no.2 injector does not feels as strong as the other 3. Admittedly it is a pretty Heath Robinson way of checking something but usually the simplest tests are the best. Would it be worth performing a leak-off test on the injectors before carrying anything else out such as cam/crank/coolant sensor checks?

Any help is much appreciated.

TIA
John

It won't be the cam/crank/coolant sensor.---Nor the glow plugs. ( Pre-heat system. )

Sounds like an injector .-- Leak back test will soon tell you.

Jamiewelch · 5th January 2021, 07:07

Quote:

Originally Posted by jc82

Hello all.

2003 MG ZT-T+ CDT

I've just acquired the above car and am so far very happy with it. It's not perfect with a few bits of interior trim needing re-attached and I've already discovered the absolute joy of changing knackered projection headlamp bulbs!

One issue that's bugging me slightly and one I hope someone can help with is it's not a great starter. It turns over as normal and then gets quicker as if the fuel pressure is building up before it starts. Once going it idles sweetly and performs perfectly. It had a new battery and starter motor fitted just before I bought it and it does start better from cold. I'm assuming I can rule out a faulty preheat system with this being the case. I've changed the diesel filter and added a diesel cleaner, so far with very little improvement.

One thing I did notice whilst idling is that if I put my hands on the injector pipes, no.2 injector does not feels as strong as the other 3. Admittedly it is a pretty Heath Robinson way of checking something but usually the simplest tests are the best. Would it be worth performing a leak-off test on the injectors before carrying anything else out such as cam/crank/coolant sensor checks?

Any help is much appreciated.

TIA
John

Get it on live data and see if the high pressure hits 30000kpa within a second of cranking, if it doesn't it is most likely regulator related on the HPFP. If it does then it is most likely injector related.

jc82 · 6th January 2021, 20:00

Many thanks for the replies, particularly Andy and his experiences.

I'll aim to get a leak-off test done soon. I'll also see if I can find anyone local to me that might have a T4 to check the fuel pressure, would a generic device such as a Snap-On Solus or even TOAF software give the pressure readings?

Cheers
John

trikey · 7th January 2021, 09:56

Send Astraeus or cossie dunc a pm, they are both in your area.

stevestrat · 7th January 2021, 10:06

Quote:

Originally Posted by trikey

Send Astraeus or cossie dunc a pm, they are both in your area.

Dunc is closer out in Whitburn, about 30 miles away,

jc82 · 9th January 2021, 11:36

That's great. Whitburn is about 30 mins from me so I'll give Dunc a message.

One other thing I've noticed is the heater taking a while to heat up and even then it's not that hot, a classic sign of a stuck-open or even removed stat. The coolant also looks quite rusty so I'll do a flush and refill as a matter of course and I've ordered one of the inline stats that fit under the inlet manifold. I'm aware this could cause over-fuelling and may also be a cause of the hot starting issues.

Thanks again
John

bl52krz · 9th January 2021, 19:39

I don’t know if you are aware, but the diesel will take about 6/9 miles to get to the proper working temperature in this freezing weather. If you have a fbh it will be only a round 2/3 miles. Because they are more efficient than petrol engines, they take longer to warm up. Use the obd to check what temp it is getting to. You can run with it in the correct program, (7) and it shows the running temp.

hogweed · 10th January 2021, 16:01

Quote:

Originally Posted by bl52krz

I don’t know if you are aware, but the diesel will take about 6/9 miles to get to the proper working temperature in this freezing weather.

In the frozen wastelands known as N Ireland, this is a real pain - even on a 10 or 15 mile journey, the heater can only be really getting going as you arrive

Limitation of this endearing model, I'm afraid...

And yes, my stat is running at about 85

3rd January 2021, 12:54	#1
jc82 Newbie MG ZT-T Join Date: Jan 2021 Location: Musselburgh Posts: 8 Thanks: 0 Thanked 2 Times in 2 Posts	Possible injector fault Hello all. 2003 MG ZT-T+ CDT I've just acquired the above car and am so far very happy with it. It's not perfect with a few bits of interior trim needing re-attached and I've already discovered the absolute joy of changing knackered projection headlamp bulbs! One issue that's bugging me slightly and one I hope someone can help with is it's not a great starter. It turns over as normal and then gets quicker as if the fuel pressure is building up before it starts. Once going it idles sweetly and performs perfectly. It had a new battery and starter motor fitted just before I bought it and it does start better from cold. I'm assuming I can rule out a faulty preheat system with this being the case. I've changed the diesel filter and added a diesel cleaner, so far with very little improvement. One thing I did notice whilst idling is that if I put my hands on the injector pipes, no.2 injector does not feels as strong as the other 3. Admittedly it is a pretty Heath Robinson way of checking something but usually the simplest tests are the best. Would it be worth performing a leak-off test on the injectors before carrying anything else out such as cam/crank/coolant sensor checks? Any help is much appreciated. TIA John

3rd January 2021, 13:35	#2
AndyN01 This is my second home Toyota RAV4 Join Date: Jun 2017 Location: Tamworth Posts: 3,070 Thanks: 2,478 Thanked 1,579 Times in 968 Posts	Hi John and welcome along. My first thought was to get a full T4 diagnostics check but in the present situation that isn't so easy coupled with the fact that folks with a T4 are a fair distance from you. My diesel and previous Rover 75/MG ZT diesels that I've owned have fired up pretty much straight away so it sounds like something is amiss. New battery & starter motor pretty much rules that line of enquiry out. If you can do a leak back test then that'll certainly move things forwards. There's several threads on here about actually doing one. A search will get you everything you need to know. Try a squirt of easy start and see if that helps. If it fires up instantly then that points to a lack of diesel/pressure for starting. Possibly a duff injector which the leak back test should confirm. Or possibly a duff pump not giving enough pressure? Or possibly a leaking "O" ring on the high pressure fuel regulator? One suggestion, and apologies if I'm teaching granny to suck eggs - check things one at time. It's very easy to get carried away and then be lost as to what it was that actually sorted it out. I'm sure some of the more knowledgeable guru's on here will be along shortly with more detailed and specific advice. Good Luck __________________ Andy. http://www.midlandsnanomeets.co.uk/ Last edited by AndyN01; 3rd January 2021 at 13:39..

7th January 2021, 09:56	#6
trikey Premium Trader Rover 75 Join Date: Nov 2010 Location: Devon Posts: 33,764 Thanks: 8,837 Thanked 14,831 Times in 8,030 Posts	Possible injector fault Send Astraeus or cossie dunc a pm, they are both in your area. __________________ Lest we forget..

9th January 2021, 19:39	#9
bl52krz This is my second home Rover 75 cdt club + Rover 2.5 KV6 Conni SE Join Date: May 2008 Location: Birmingham Posts: 11,387 Thanks: 6,587 Thanked 2,262 Times in 1,729 Posts	I don’t know if you are aware, but the diesel will take about 6/9 miles to get to the proper working temperature in this freezing weather. If you have a fbh it will be only a round 2/3 miles. Because they are more efficient than petrol engines, they take longer to warm up. Use the obd to check what temp it is getting to. You can run with it in the correct program, (7) and it shows the running temp. __________________ Great Barr, Birmingham.

6th January 2021, 20:00	#5
jc82 Newbie MG ZT-T Join Date: Jan 2021 Location: Musselburgh Posts: 8 Thanks: 0 Thanked 2 Times in 2 Posts	Many thanks for the replies, particularly Andy and his experiences. I'll aim to get a leak-off test done soon. I'll also see if I can find anyone local to me that might have a T4 to check the fuel pressure, would a generic device such as a Snap-On Solus or even TOAF software give the pressure readings? Cheers John

9th January 2021, 11:36	#8
jc82 Newbie MG ZT-T Join Date: Jan 2021 Location: Musselburgh Posts: 8 Thanks: 0 Thanked 2 Times in 2 Posts	That's great. Whitburn is about 30 mins from me so I'll give Dunc a message. One other thing I've noticed is the heater taking a while to heat up and even then it's not that hot, a classic sign of a stuck-open or even removed stat. The coolant also looks quite rusty so I'll do a flush and refill as a matter of course and I've ordered one of the inline stats that fit under the inlet manifold. I'm aware this could cause over-fuelling and may also be a cause of the hot starting issues. Thanks again John