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[Doctor Gollum]

What happens if you slap the tank whilst cranking?

Is effective enough on the Omega to prove a point, if only to confirm that the pump is a couple of stickings from dying completely

[JamesV6CDX]

I changed the pump in the tank today, the whole assembly, with the sender unit, etc. £60 from eBay, arrived next day, two year guarantee. Dead easy to do, from above.

One of these:



Bring on the slating, for that pattern part. But It's a very rapid, and very cheap way of getting mobile again.

Tomorrow, I'm going to wire in a switch, so that the pump only runs for the initial start up, prior to the switch to LPG.

So, chances are, in those conditions, it'll last for ages

As an aside, it's one of the best LPG installs I've ever seen. And no, regrettably, it wasn't mine.

I took a real gamble with this car, which paid off... but that's for another thread, with piccies

[JamesV6CDX]

I changed the pump in the tank today, the whole assembly, with the sender unit, etc. £60 from eBay, arrived next day, two year guarantee. Dead easy to do, from above.

One of these:



Fired up first time after that

Bring on the slating, for that pattern part. But It's a very rapid, and very cheap way of getting mobile again.

Tomorrow, I'm going to wire in a switch, so that the pump only runs for the initial start up, prior to the switch to LPG.

So, chances are, in those conditions, it'll last for ages

As an aside, it's one of the best LPG installs I've ever seen. And no, regrettably, it wasn't mine.

I took a real gamble with this car, which paid off... but that's for another thread, with piccies

[JamesV6CDX]

Sorry for the double post 

[Nick W]

Sorry for the double post 

That's alright, it's what most of the forum expect from using pattern parts.........

[Entwood]

Sorry for the double post 

Not a problem to me !

Glad to hear a) you are keeping well and active, b) problem is solved quickly and cheaply !!

IMHO with the ages of all the cars we try and keep going, pattern parts are going to become the only option on may occasions !!

[Viral_Jim]

James, before you go ahead with you switch, do you know if there is any kind of ECU learning on the fuel pump run time relative to fuel rail pressure (that DTM bloke might know). 

The reason I ask is that I remember reading in a Saab forum about people trying to lpg the GM 2.8T V6. One of the issues is that the Saab learns fuel pressure relative to fuel pump effort. So running on Lpg would cause the ECU to back off the fuel pump (as the rail pressure doesn't drop on Lpg) until Ultimtely the car would no longer run on petrol.

Just wondering if cutting off the fuel pump (so presumably 0v draw) could give you a similar issue. 

[JamesV6CDX]

Sorry for the double post 

Not a problem to me !

Glad to hear a) you are keeping well and active, b) problem is solved quickly and cheaply !!

IMHO with the ages of all the cars we try and keep going, pattern parts are going to become the only option on may occasions !!

Cheers, Nige

If it were an under-car job, I'd have likely sent it to Serek....but thankfully, just had to fold up the seats, remove some carpet and tie it up... and the pump is accessible from the top, via an access hatch! A little fiddly, but by no means difficult...  a novice to intermediate DIYer like me could take that on no problem

[JamesV6CDX]

James, before you go ahead with you switch, do you know if there is any kind of ECU learning on the fuel pump run time relative to fuel rail pressure (that DTM bloke might know). 

The reason I ask is that I remember reading in a Saab forum about people trying to lpg the GM 2.8T V6. One of the issues is that the Saab learns fuel pressure relative to fuel pump effort. So running on Lpg would cause the ECU to back off the fuel pump (as the rail pressure doesn't drop on Lpg) until Ultimtely the car would no longer run on petrol.

Just wondering if cutting off the fuel pump (so presumably 0v draw) could give you a similar issue. 

You raise a good point, and I'll check - thank you! i expect it will be fine, I did a long way with the fuel pump disconnected, and no ill effects, but I'll definitely look into it.

In all honesty, the fuel pump should be ok to run all the time, I was just considering ways to save / prolong it's life, given it's a pattern one, and to my knowledge, doesn't need to run when the car is on LPG

[Nick W]

In all honesty, the fuel pump should be ok to run all the time, I was just considering ways to save / prolong it's life,

It IS fine to run all the time, as it does when running on petrol.


BUT, it must be sitting in fuel, and pumping fuel. That's what keeps it cool.


As lots of LPG users rarely have more than a dribble of fuel in the tank, that often doesn't happen.

[Viral_Jim]

You raise a good point, and I'll check - thank you! i expect it will be fine, I did a long way with the fuel pump disconnected, and no ill effects, but I'll definitely look into it.

In all honesty, the fuel pump should be ok to run all the time, I was just considering ways to save / prolong it's life, given it's a pattern one, and to my knowledge, doesn't need to run when the car is on LPG

No worries, James - as you say I'm sure it will be fine.

Tbh I'm just glad to see you back on here and to hear you're well and obviously getting about the place 

[JamesV6CDX]

As lots of LPG users rarely have more than a dribble of fuel in the tank, that often doesn't happen.

Lesson learned  - the hard way 

[Marks DTM Calib]

James, before you go ahead with you switch, do you know if there is any kind of ECU learning on the fuel pump run time relative to fuel rail pressure (that DTM bloke might know). 

The reason I ask is that I remember reading in a Saab forum about people trying to lpg the GM 2.8T V6. One of the issues is that the Saab learns fuel pressure relative to fuel pump effort. So running on Lpg would cause the ECU to back off the fuel pump (as the rail pressure doesn't drop on Lpg) until Ultimtely the car would no longer run on petrol.

Just wondering if cutting off the fuel pump (so presumably 0v draw) could give you a similar issue. 

Looking at the fuel system schematics, its similar to the GM setups of the 90s.

So pump raises the pressure, this is controlled by the fuel pressure regulating valve which returns excess to the tank.

The systems that modulate the fuel pressure are usually direct injection setups 

[Doctor Gollum]

Sounds like the same set up as the Monaro