Hello all. I have a 1989 XJS convertible with 69K miles. I am having a problem with the engine (v-12) dying after about 20 min. drive time. I have read every post on this site related to this problem. I see that there are several others that are having or have had this problem. The car acts as if it were out of gas. You can keep the engine running by just slightly feathering the throttle. But it will eventually die and will not refire. After about 10-15 minuets of cranking the engine will fire up and run perfect. From reading past posts I understand that the fuel filter could be the problem. Or the fuel pump. Or the screen in the fuel sump tank. Or the fuel circulating from the engine back to the fuel tank could be to warm causing a vapor lock. Or it could be a combination of some of the above. I have also read Kirby Palm's book concerning fuel delivery. Today I started investigating the problem. My intention was to replace the fuel filter and clean the screen in the surge tank. Do the simplest cheapest things first. I removed the spare tire the battery and the battery box and found a surprise ! Someone in the past has bypassed the surge tank ! The fuel line comes out of the main tank goes to the fuel pump then to the fuel filter then to the engine. There is one small line still connected from the main tank to the surge tank. I assume this to be a vent line. Now what should I do ? Should I leave it like it is and change the filter and maybe the pump ( it whines very loudly)? Or should I re-plumb everything back thru the surge pump and clean the screen replace the filter and maybe the pump ? One other thing, the air conditioner belt has been removed from the compressor so I am assuming the fuel is not being cooled before it is returned to the tank. Thanks for any help/advice. This is my daily driver and I need it to be dependable. Driving this car makes one look forward to going to work ! Thanks again.

 

It sounds like the fuel pump needs to be replaced.

You can try the filter first since you will want to replace that anyway, especially if you do not know the last time it was replaced.

Your injectors may also need cleaning but given the age of the vehicle and you relying on it I would start with the fuel pump, the filter attached to it, and clean the tank if it has the fuel pump in the tank like my 94 xjs. ...the tank will have to be removed in this case. Not a difficult job but get some beers and expect to spend a half a day on it.

I'm doing this job right now and found a Bosch fuel pump on Amazon for less than $80.