Fuel tank inspection and filter replacements.

If you recall this blog:

http://erwinxjs.blogspot.nl/2016/09/engine-shutting-off-stalling.html

It is still an outstanding problem to be solved. Now the car is not idling high anymore I can look into this issue. Of course I did search around a little already but nothing related could be found that described the problem I was experiencing. In any case it is likely to be a fuel related matter. The following was very usefull and learning material:

http://www.jag-lovers.org/books/xj-s/07-FuelEFI.html

And the following document was even better in explaining the complete setup:

http://www.jagrepair.com/images/Electrical/Elect-Tech%20All/81%20-%2088%20XJS%20Engine%20Performance%20S58.pdf

(now available in the download folder).

This diagram gave a good basic overview of the fuel flow:

From this I learned there are two fuel tanks, one main and one sump tank. And also I now noticed there is another fuel filter in the sump tank next to the normal fuel filter.

As said, the car is starting and running fine. It was just that after a longer drive (about 20 - 30 min drive) it would shut off. The car itself is running at normal temperature and is definately not overheated. So I don't think it's caused by some kind protection mechanism that cuts it off. I also don't think it's caused by the fuel pump (why would it only manifest after 20-30 min). It looks like this one has been replaced in the past though. Also the fuel filter looks ok - not sure if or when was that replaced. But I'm pretty sure the filter in the sump tank has not been replaced. Given the fact it has been parked for a very long time I suspect there must be some kind of dirt or other polution in the main tank. Nevertheless the previous owner has been driving about 2.500 km last year. I wonder if he never ran into problems. Perhaps he has been making small trips only? I know he told me that he once ended up the emergency lane on the highway due to a lack of gas. Or perhaps he encountered the same problem as I did? 

When replacing the fuel sender unit it was clearly heavy corroded. I now suspect the gas is not flowing well from the main fuel tank to the sump tank due to contamination (slush) and likely also having a dirty sump tank filter. My guess is that gas is running out from the sump tank due to limited gas flowing from the main tank in combination with a dirty filter. Or else the latter might cause a pressure issue. This is something I'm going to check tomorrow. I did order both fuel filters from SNG Barratt but unfortunately they have not arrived yet. Nevertheless I will have a look.