It appears that the fuel pump in my 1992 XJ-6 Sovereign failed again last night. This would be the 3rd fuel pump failure in a year, 2 by previous owner and one for me. I purchased the car after the 2nd failure for the previous owner, so this will be the 2nd fuel pump that I have to install.

My question is; what should I check as a contributing factor to numerous fuel pump failures? I have my doubts that the pumps are just failing, but I'm not sure what to check.

Thanks in advance for any and allow advice and/or help.

 

These cars were notorius for eating fuel pumps and it seems there were a bad batch of fuel pumps manufactured for these cars. I remember having to replace some fuel pumps in XJ40's and eating the labor because they wouldn't last a year.

One thing is don't try and let the fuel tank go below a 1/4 full. These pumps rely on the gas in the tank to keep them cool.

 

Are you replacing the entire pump unit or just the insert that drops into the white container? If the o-ring in the bottom does not seal properly, it won't work. Even the slightest nick or tear can render a "good" pump useless. The reason folks do the insert instead of the entire unit is about an $800 price difference. (yikes!)

 

Does anybody know what the voltage to the fuel pump is supposed to be?

If I disconnect the electrical connection in the trunk I don't get any reading at that point which means the fuel pump isn't getting any voltage. Only problem I don't know what the reading should be and if it only reads for a few seconds when the car (ignition) is turned on or if it is a consistent voltage reading.

All of the fuses and the fuel pump relay appear to be OK, so if it's not get voltage and it should be I'm not sure where else to check for a point of failure.

I'm hoping it turns out to be a simple fuse or relay I don't know about and that the fuel pump hasn't actually failed again, afer only 6 months of service with a new pump.

Thanks.

 

OK, so I got the "bad" fuel pump out and if I put 12V directly to it it runs like a champ. So just for S&G I reinstalled it and closed everything up like it's supposed to and I get nothing when I turn the key on.

Power Issue?

As I stated in my previous post I was having trouble getting any readings with my meter, but I made up some wires wrapped around my meter leads that would fit into the connections and pins on the car and was finally able to get some readings.

Voltage up to the fusible link is 11.75 approximate average.

Voltage after the fusible link is .62 approximate average.

If the voltage is supposed to remain 12V approximate all the way to the fuel pump I would say I discovered my problem.

Or is it supposed to step down to less than 1 volt at or after the fusible link?

Is my test and reasoning flawed?

The fuel relay and all fuses are good.

I've never seen a bad fusible link; what does one look like?

Can I buy a new fusible link and splice it in? Or do I have to buy that 3-4 foot section of wire/s that have a the correct connection on both end?

All other fuel system connections. wires, seals, gaskets, filters look good.

What would cause the fusible link to go bad? Should I check something else to make sure I don't have an issue that caused the fusible link to fuse and will cause the problem again in the future.

Or the fact that the fuel pump ran like a champ when it was out of the tank with 12V applied directly to the leads doesn't really prove anything and I should still replace the fuel pump (again).

All opinions, help, advice welcomed.

As a side note I bought the manuals for my car on CD and can't get to play on either my MAC or my PC running Vista.

But while I am sleeping to night I'll be downloading the free manuals from Cristo(SP?). Many thanks for that!