1.8T/260 Fuel Pump 4.5 BAR Suitable Alternatives WFX000290

[oxfordblue75]

I have just checked and the seller is away until the 16th of sept , so you won't see the listing til then . It was the electric pump that fits inside the in tank housing .

[The Mighty Quinn]

Ok, so I took into replacing the fuel pump today and after some extreme fiddling, it's all sat back in the tank (with the in-tank connections made).

However , is there a trick to getting the pump sitting correctly in its aperture? Mine is sitting about 15mm proud of the tank and I can't get the locking ring back on

Is there a moulding in the tank that the pumps sits into?

Any advice would be greatly appreciated.


Cheers,
Karl.

[The Mighty Quinn]

Legend!

Thanks very much, John. There was no way that I'd have figured that out - not today. And probably not ever

Very much a case of: "easy, when you know how".

So, for any others having difficulty with reseating a fuel pump, the black circular seal fits inside the tank aperture, with the edge of the tank aperture resting between the two flanges of the seal.

Thanks again

Changing the pump has not cleared the hesitation under throttle entirely (O2 sensors and ATF change next), but it seems to have cured the slow start-up issues that I've had the past couple of months.

Cheers,
Karl.

[Lovel]

To whom it may concern and perhaps will help someone trying to isolate if the fuel pump is indeed faulty or not. Further to my 1st post investigations regarding this thread, I recently carried out some tests on a new (pattern) and original fuel pumps, I also took readings at different positions on a 1.8T to clarify things in my mind. BTW, the engine on this 1.8T goes like a scalded cat and there is absolutely no hesitation with either pumps fitted.

Another thing that has always puzzled me was why does the 1.8T need a higher pressure system compared to the NASP. Well apparently its all to do with manifold pressure when on boost. If there was not enough pressure in the fuel rail there is potential for the injectors not to dump their atomised fuel into the manifold, hence the reason the higher pressure system is specified. I guess that a NASP fuel pump may work (perhaps changing the regulator on the filter housing to 1.8T 4.55bar rating) but at higher revs one may start to get fuel starvation issues.

Anyway. If one follows RAVE instructions to the letter the fuel test should be made with the engine running, 4.3bar should be seen, however given that there is a damper (regulator) at the end of the fuel rail which is rated at 3.5bar, I cannot understand how RAVE can obtain quote that value? This is where I believe RAVE is incorrect. Typically in a number of 1.8T models I have noted 2.8bar at idle, and with the vacuum hose removed from the damper (regulator) you get about 3.2bar with engine running. In my opinion testing with the damper (regulator) on the end of the fuel rail is flawed, and a fuel pump which has got marginal output of say 3bar would not be picked up in the pressure test from the shraeder valve on the fuel rail.

The correct way to establish if you fuel pump or indeed the filter housing is intact and not backed off is to disconnect the fuel line in the engine bay and run a pressure gauge directly bypassing the engine bay fuel rail damper (regulator).


Original pump reading engine at idle, vacuum fitted to regulator note 2.8bar reading, taken from the schraeder valve:



Original pump, reading 4.6bar taken as ignition is switched on before it cuts out, and directly from disconnected fuel hose. I don't know what the original MG Rover pump spec is when new, perhaps its higher? :




New pattern pump reading 5bar taken as ignition is switched on and before it cuts and directly from the disconnected fuel hose. (The fuel pump spec new is 6.55bar). Note the disconnected hose, the light blue plastic connector inserted straight into a made up pipe to the pressure gauge. I find it strange to obtain this higher reading of 5bar as there is a regulator fitted to the filter housing of 4.55bar, but perhaps the discrepancy is due to the high volume from the pump and the regulator not coping? I used an old fuel rail quick connect fitting to adapt to the pressure gauge:



Fuel rail damper (regulator) rated at 3.5bar:



System description
The filtered fuel passes though a 4.55bar regulator on the side of the filter housing on the near side of the vehicle it arrives at the fuel rail where the damper 3.5bar (regulator) irons out any spikes as each injector is opening to maintain a constant fuel pressure under all conditions at the injector, more so important for turbo models with high inlet manifold pressures.

[Lovel]

For anyone interested in changing the fuel pumps over here are some photos. Pretty straight forward as can be seen in the photos, just make sure the bottom of the pump engages with the bottom stub on the large gauze. I noticed that the pattern pump does not engage so well as the original, but there does not seem to be any detrimental effect.

The only issue you will encounter is removing the swaged on connection to the corrugated feed hose, as it is not reusable. Once you remove the clip, heat the hose up gently before trying to remove and fit a sturdy hose clip that evenly grips the circumference, I'm not so keen on jubilee clips as the tend to pinch too easy.

A tiny light smear of molykote silicone grease works wonders when fitting O-rings and makes assembly and alignment much easier

[Lovel]

Interesting scenario with my 1.8T these last few days. I noticed that the engine takes a fraction of a second more turn of the starter to fire. It starts on first turn of key but not as quickly as usual.

Upon turning on the ignition the initial prime does not seem to occur, this I think is leading to the minuscule sluggish start up. The car runs faultless otherwise right across the rev range. I somehow think it is relay based or the driver from the MEMS ECM perhaps at fault?

Any thoughts?

I have only once seen the MEMS ECM driver for the fuel relay fail, but that was jammed on even with the engine not running. I suppose it could also fail another way could it? Will check the fuel relay as a first port of call.

[The Mighty Quinn]

Originally Posted by Lovel

Interesting scenario with my 1.8T these last few days. I noticed that the engine takes a fraction of a second more turn of the starter to fire. It starts on first turn of key but not as quickly as usual.

Upon turning on the ignition the initial prime does not seem to occur, this I think is leading to the minuscule sluggish start up. The car runs faultless otherwise right across the rev range. I somehow think it is relay based or the driver from the MEMS ECM perhaps at fault?

Any thoughts?

I have only once seen the MEMS ECM driver for the fuel relay fail, but that was jammed on even with the engine not running. I suppose it could also fail another way could it? Will check the fuel relay as a first port of call.

Hi Gary,

No idea about the fuel pump relay, I'm afraid.

However, it might be worth checking your battery's state of charge.

My car had similar symptoms prior to changing the fuel pump way back, but I also noticed very similar symptoms just prior to my battery giving out earlier this year (just took an extra turn or two to get going) - replaced battery and all was well again.

Even young batteries can suffer in our cars during the cold weather, with courtesy lights sticking on etc.


Cheers,
Karl.

[Lovel]

Originally Posted by The Mighty Quinn

Hi Gary,

No idea about the fuel pump relay, I'm afraid.

However, it might be worth checking your battery's state of charge.

My car had similar symptoms prior to changing the fuel pump way back, but I also noticed very similar symptoms just prior to my battery giving out earlier this year (just took an extra turn or two to get going) - replaced battery and all was well again.

Even young batteries can suffer in our cars during the cold weather, with courtesy lights sticking on etc.


Cheers,
Karl.

Interesting you mention the battery though as the last couple of weeks there has been a subtle change in the turning over sound that made me think the battery is on the turn. The battery has had a remarkably long life. Perhaps this is a sign?