mgzt 190 Cam sensor & fuel pressure

Parnek1 · 28th October 2018, 12:44

Yesterday I replaced the thermostat and today it drove for 10 miles without fault, then the car lost power and will not start. I did have a leaking injector of which I fixed, I am now wondering if the fuel is now under pressure even though it was running today??

Also I hear the Cam sensor could be the issue, due to me not knowing where it is I may have knocked it when working on it yesterday, can someone please tell me where it is so I can investigate?

Also any ideas of what the issue could be after knowing that I replaced the Thermostat 10 miles ago.

Any help appreciated.

T-Cut · 28th October 2018, 14:05

The fuel delivered at the rail should be around 50psi or it won't start. You can check the pressure using a mechanical tyre gauge on the Schrader valve. This is will be seen at the end of the rear fuel rail and has a blue cap. Get an assistant to turn on the ignition while you handle the tyre gauge. It must be a mechanical gauge for fire safety. Avoid spraying petrol obviously, so have plenty of rags ready.

If the pressure is much less than 50 psi then check the fuel filter for slackening (FFS) of the module/cap.This is located in the fuel tank on the nearside/left. There are HowTos on doing this. You should have the orange clip fitted. if not, fit one. This will elminate possibility of fuel leakage/pressure drop/related non-statring issues.

Parnek1 · 28th October 2018, 14:17

As I am in my own can i test the fuel pressure with the ignition on or do u have to turn the engine over for the pressure to be at 50psi. I did put an allen key in the gauge just to check to see if there was pressure and run the risk of getting covered in petrol but absolutely nothing came out at all?

SD1too · 28th October 2018, 17:51

Quote:

Originally Posted by Parnek1

As I am in my own can i test the fuel pressure with the ignition on ...

Yes Kev. When you turn on the ignition the pump runs for a few seconds to pressurise the system. If you turn the engine over the pump will run continuously.

Simon

T-Cut · 28th October 2018, 21:23

Quote:

Originally Posted by Parnek1

As I am in my own can i test the fuel pressure with the ignition on or do u have to turn the engine over for the pressure to be at 50psi.

Maybe read through this thread: https://www.the75andztclub.co.uk/for...bar+fuel+gauge

and check out post 20. That reduces risk of petrol spray and flattening the battery.

TC

Parnek1 · 29th October 2018, 16:48

Today I checked for pressure in the fuel rail and nothing was there as all this as a friend was turning the engine over, I checked the fuel filter and it has an orange clip already, I could hear the fuel pump working and checked the fuse all good. Why would there no fuel pressure at all and what do I need to do to get it back?

Any help appreciated...

Ched · 29th October 2018, 17:18

Have you pushed the fuel line on firmly till it clicks on the manifold?

T-Cut · 29th October 2018, 18:06

I'll assume there's no leakage from any of the fuel rail joints or any obvious reason for lack of pressure. However, there are reports starting to come in of petrol pumps failing. They are generally regarded as very robust, but everything has a lifetime I guess. If there's no or little fuel coming from the Schrader valve when the pump is running, then either the pump has failed or the fuel pressure is bleeding out of the filter module. The orange clip is a good sign, but the o-ring seal that holds the pressure could be fatigued or broken. The only way to eliminate that is to replace the seal and refit the orange clip.
After doing that and there's still little or no fuel pressure at the Schrader valve, it looks like pump failure.

TC

SD1too · 30th October 2018, 07:35

Quote:

Originally Posted by Parnek1

Why would there no fuel pressure at all ...

I'm with Ched on this. It would be an incredible coincidence that your fuel pump has chosen to fail so soon after you've disconnected the fuel lines, particularly as you say that you can hear the pump operating.

Quote:

.... and what do I need to do to get it back?

Retrace your steps and examine every part of the fuel line which you disconnected. You could start at the very beginning by locating the supply hose rising up behind the battery box. This terminates in a plastic connector which mates with the fuel pipe running parallel with the throttle body. Is this secure? You could detach it, place the end in a large container and be prepared for a powerful jet of fuel. Switch on the ignition and the pump should operate for a few seconds only. Do you get a burst of fuel out of the supply hose? That should confirm whether there's a problem at the tank end or at the engine.

Simon

Parnek1 · 30th October 2018, 16:25

guys I very much appreciate all of your help I found the root cause of the issue and ultimately stems from having no petrol in the tank whatsoever. I now have petrol I have no leaks. I gained a lot of experience from this situation for example I now know that I already have an orange clip fitted to the fuel filter.. before you laugh too hard petrol gauge light was on but it was saying that was enough petrol in the tank 2 at least go a few more miles than it did.

28th October 2018, 12:44	#1
Parnek1 Regular poster mg zt Join Date: Sep 2015 Location: Peterborough Posts: 33 Thanks: 17 Thanked 4 Times in 3 Posts	mgzt 190 Cam sensor & fuel pressure Yesterday I replaced the thermostat and today it drove for 10 miles without fault, then the car lost power and will not start. I did have a leaking injector of which I fixed, I am now wondering if the fuel is now under pressure even though it was running today?? Also I hear the Cam sensor could be the issue, due to me not knowing where it is I may have knocked it when working on it yesterday, can someone please tell me where it is so I can investigate? Also any ideas of what the issue could be after knowing that I replaced the Thermostat 10 miles ago. Any help appreciated.

28th October 2018, 14:05	#2
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	The fuel delivered at the rail should be around 50psi or it won't start. You can check the pressure using a mechanical tyre gauge on the Schrader valve. This is will be seen at the end of the rear fuel rail and has a blue cap. Get an assistant to turn on the ignition while you handle the tyre gauge. It must be a mechanical gauge for fire safety. Avoid spraying petrol obviously, so have plenty of rags ready. If the pressure is much less than 50 psi then check the fuel filter for slackening (FFS) of the module/cap.This is located in the fuel tank on the nearside/left. There are HowTos on doing this. You should have the orange clip fitted. if not, fit one. This will elminate possibility of fuel leakage/pressure drop/related non-statring issues. Last edited by T-Cut; 28th October 2018 at 14:08..

29th October 2018, 16:48	#6
Parnek1 Regular poster mg zt Join Date: Sep 2015 Location: Peterborough Posts: 33 Thanks: 17 Thanked 4 Times in 3 Posts	fuel pressure. Today I checked for pressure in the fuel rail and nothing was there as all this as a friend was turning the engine over, I checked the fuel filter and it has an orange clip already, I could hear the fuel pump working and checked the fuse all good. Why would there no fuel pressure at all and what do I need to do to get it back? Any help appreciated...

28th October 2018, 14:17	#3
Parnek1 Regular poster mg zt Join Date: Sep 2015 Location: Peterborough Posts: 33 Thanks: 17 Thanked 4 Times in 3 Posts	As I am in my own can i test the fuel pressure with the ignition on or do u have to turn the engine over for the pressure to be at 50psi. I did put an allen key in the gauge just to check to see if there was pressure and run the risk of getting covered in petrol but absolutely nothing came out at all?

29th October 2018, 17:18	#7
Ched I really should get out more....... MG ZT V8, MGZT 135 derv ,MG TF 135 Join Date: Dec 2011 Location: Romsey Posts: 2,293 Thanks: 553 Thanked 573 Times in 385 Posts	Have you pushed the fuel line on firmly till it clicks on the manifold?

29th October 2018, 18:06	#8
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	I'll assume there's no leakage from any of the fuel rail joints or any obvious reason for lack of pressure. However, there are reports starting to come in of petrol pumps failing. They are generally regarded as very robust, but everything has a lifetime I guess. If there's no or little fuel coming from the Schrader valve when the pump is running, then either the pump has failed or the fuel pressure is bleeding out of the filter module. The orange clip is a good sign, but the o-ring seal that holds the pressure could be fatigued or broken. The only way to eliminate that is to replace the seal and refit the orange clip. After doing that and there's still little or no fuel pressure at the Schrader valve, it looks like pump failure. TC

30th October 2018, 16:25	#10
Parnek1 Regular poster mg zt Join Date: Sep 2015 Location: Peterborough Posts: 33 Thanks: 17 Thanked 4 Times in 3 Posts	guys I very much appreciate all of your help I found the root cause of the issue and ultimately stems from having no petrol in the tank whatsoever. I now have petrol I have no leaks. I gained a lot of experience from this situation for example I now know that I already have an orange clip fitted to the fuel filter.. before you laugh too hard petrol gauge light was on but it was saying that was enough petrol in the tank 2 at least go a few more miles than it did.