'99 Fuel pump query

Hi all,

Firstly I ought to introduce myself; my name's Andy, I live in the UK and drive a '99 XJ with an LPG (propane) conversion. Although I've been a member on here for two years or so I've never actually posted as I've always found the answers to my questions. Until now that is....

My fuel pump packed up today and after a bit of diagnosis I'm convinced that the pump is dead as there's still power to it when the ign is turned on.

A new pump module is over $450 in the UK but there are loads of replacement pumps advertised in the US which I can get shipped to the UK for less than $100 all in.

My question is can the pump be changed out of the module or do I have to replace the whole module? There's nothing wrong with the float gauge.

I've tried searching the forum but can't find a specific answer to this.

Great forum by the way.

You can purchase the pump separate from the assembly at rockauto.com so it would appear that you can just replace the pump.

Don't forget to get a new filter and strainer to go in there.

if your 99 runs on propane i think you are going to need anther type of fuel pump, other than the stock one? mike

x99j said:

if your 99 runs on propane i think you are going to need anther type of fuel pump, other than the stock one? mike

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No, it's ok Mike. When the LPG system was installed a half-size petrol (gas) tank was fitted but the original fuel pump was used.

With the LPG system, the Jeep starts on petrol and then when the coolant reaches 40 deg C the system automatically switches over to LPG.

When It switched over to LPG mode, does it just cut off voltage to the regular (petrol) pump, or is it a mechanical ball valve type? Just curious.

RenoXJ said:

When It switched over to LPG mode, does it just cut off voltage to the regular (petrol) pump, or is it a mechanical ball valve type? Just curious.

Click to expand...

The LPG has it's own ECU which fools the original ECU into shutting off the petrol injectors whilst maintaining all existing parameters. It doesn't shut the fuel pump off though so it is recommended that you keep at least a quarter of a tank of petrol to keep the pump lubricated. In this respect its therefore no different to running on petrol

With the price of petrol over here at the moment, using LPG is the only way I can afford to run a 4.0L XJ!

More info on the Prins VSI LPG system I have is here: http://www.prinsautogasuk.co.uk/

Thats what I was thinking. It maybe "dead headed" the stock pump and burnt it out?

Just a thought. but its a return style syetem.. Hmm.

You can replace just the pump if you want but I'd seriously consider replacing the entire assembly when you have the gas tank out.

When you buy, stay away from "el-cheapo". Fuel pump hardware is definitely buyer beware. There have been a number of threads on this forum and others with people having trouble with ebay and no-name fuel pump assemblies.

Buy a reputable brand and you should be okay.