MG Zt-t 1.8T Non-start. - Page 2

T-Cut · 23rd September 2020, 15:41

Quote:

Originally Posted by KillerKilane

After fitting the filter, I added 3 liters of fuel, as I understood this was recommended after having done the change).

The reasoning for this is as follows. The fuel tank is divided into two sections by a 'ridge'. The left side has the fuel filter and the right side is where the pump is located. When the fuel level drops lower than the ridge, the fuel level in each side is kept more or less equal by a simple 'recirculation' system. As the pump empties the RHS, it's fed into the filter module where part of the flow operates the recycle of fuel in the LHS. This keeps the pump inlet submerged in fuel. IF you get FFS, the fuel leaks from the filter case and it can't operate the recycle. So, fuel is transfered from right to left in the tank. If you persistantly try to start the engine, the pump will eventually be starved of because all the fuel is in the LHS. So, after fixing the filter using a new o-ring/orange clip, you may have to add fuel to the RHS so the pump will operate and start the car. I suspect that the gurgling sound you report is air being drawn into the pump. Adding just three litres of fuel may not be enough to ensure the pump inlet is fully submerged (it sits in a pickup cup.) I suggest to add another 5 litres.

Quote:

I'm also gonna check the fuel pressure at the rail today (think I found the Schroder valve), but not sure if I could check the pressure by myself, or if I need someone to crank the engine while I measure?

If you're planning to use a tyre pressure gauge, it is a 2-man job. If you attach a proper dial gauge to the valve, you can do it alone as described by vitesse.

Note that a non-electrical tyre gauge is essential for fire safety and that there is a distinct possibilty that fuel might be sprayed out as you press it onto the Schrader valve.

TC

KillerKilane · 23rd September 2020, 23:20

T-Cut and Yorkshire GOC, thanks for even more useful pointers and info!
I'm happy to tell that you were right from the start:
"From everything you've described, my gut feel is there's still a problem with the fuel filter. Did you replace all the o-rings exactly as they were? I ask because mine had the same problem after renewing the filter. I'd not replaced the large ring correctly before fitting the orange clip."
Spot on!
I was just so reluctant to go through the whole ordeal again, but luckily I did follow your suggestion. Thanks!
The larger O-ring that is inside the filter capsule, sealing the two parts, was not in position. The first time I struggled a bit to twist the cap and the bottom together, so the ring must have moved then. This explains the gurgling sound (air in the system).
I struggled even more the second time around, trying to lock/twist the parts together. It was terribly tight, although I had used quite a lot of lube.
But I finally fitted the parts, and the car started the second I started cranking. No delay! Right on!

I am very grateful for all help and pointers!

23rd September 2020, 23:20	#12
KillerKilane Newbie MG ZT-T Join Date: Apr 2019 Location: Erfjord Posts: 6 Thanks: 0 Thanked 1 Time in 1 Post	T-Cut and Yorkshire GOC, thanks for even more useful pointers and info! I'm happy to tell that you were right from the start: "From everything you've described, my gut feel is there's still a problem with the fuel filter. Did you replace all the o-rings exactly as they were? I ask because mine had the same problem after renewing the filter. I'd not replaced the large ring correctly before fitting the orange clip." Spot on! I was just so reluctant to go through the whole ordeal again, but luckily I did follow your suggestion. Thanks! The larger O-ring that is inside the filter capsule, sealing the two parts, was not in position. The first time I struggled a bit to twist the cap and the bottom together, so the ring must have moved then. This explains the gurgling sound (air in the system). I struggled even more the second time around, trying to lock/twist the parts together. It was terribly tight, although I had used quite a lot of lube. But I finally fitted the parts, and the car started the second I started cranking. No delay! Right on! I am very grateful for all help and pointers!