I filled up both tanks on Tuesday at a local filling station. On the way home the engine stuttered a bit then recovered. Didn’t use the car on Wednesday. On Thursday she wouldn’t start.

Went through the various checks and eventually discovered that there is water contamination in the petrol. Looks like the filling station has water ingress into their storage tanks.

Today I drained both tanks of the Jag. Using a clear 10L container, I could then suck the water out from below the fuel with a suction pump. From a total of about 70L I have removed about 2L of water.

Now the car still won’t start. Tries a bit but won’t catch. My plan for tomorrow is to check the injectors. I am wondering if they might have problems with passing the water-contaminated fuel? Although I have drained all the fuel, the injectors sit lower than the fuel rail so will still have some of the suspect fuel in the short feed pipes until I disconnect them.

Any comments gladly received if other forum members have experienced similar problems. Incidentally I have checked that the drain tubes next to the fuel fillers are not blocked on the car, so I am confident the water has not got in that way. It is too much of a coincidence for both tanks to have water in immediately after filling up too.

 

Water can enter the tanks from the area around the filler cap. This is especially the case if the rubber seals are tired and the drain tubes are blocked. They have to be checked regularly if the car lives outside in heavy rain. In addition, water condenses on the walls of the tank, particularly in humid environments; it's best to keep the tanks full.

If rain water has entered the tanks, it will have taken some dirt with it that can block the fuel filters. Some gets past the filter (I know it shouldn't) and causes problems elsewhere. Change the filter and flush the system as best you can.

 

Andy,
Up here in the cold country we use a product called "Heet". It is a fuel additive that is added to the fuel tank to mix with and allow the water to pass through an injector (or carb) with the fuel. When used as a preventative measure, any water that gets into the fuel will be mixed (as opposed to the natural state of fuel/water separation) and flow into the cylinders with the fuel. With small amounts of water from condensation, etc., the water passes through the system without notice. In your case the process is the same, but the engine won't run well until the remaining water in the low fuel lines and injectors is mixed and purged.

What I would do is add a full bottle (8oz I think) to 5gal of clean fuel in the tank, let the pump cycle several times without cranking, then crank normally for a couple of tries, then if it hasn't started, just let it set for maybe an hour and let the HEET mix with any water it's in contact with. Try to start the engine again, if no joy, repeat the procedure.

One caveat, there is alcohol in the product and it will have negative affects on the rubber parts of the fuel system if used on a steady basis. Because of that, they developed a friendlier version when fuel injection became the standard. Get HEET in the red container, not the yellow container. If you research and decide this will be a one-time use, either one will do the job, if you think your local fuel quality is suspect and plan to use it steadily, use the red stuff. Another possibility, because of the water emulsion being allowed to flow into the cylinders, intake, injectors, etc., if the engine is not run on a regular basis, rust can begin to develop. Very light rust, but rust non the less. I personally don't use HEET anymore because I keep the tanks full and our gas stations are very scrupulous in the care of their tanks. I used to add one bottle per winter back in the day, but I quit.

A water separator inline before the filters might be a good investment.

Dave

 

I am not sure what "Heet" is but for people who can't find it I suggest using methanol as a substitute.
It does the same thing as it mixes with water and will go through the system and mixes and burns with petrol (gasoline)
Methanol is used in drag racing "fuellers".
It is also used in some aviation jet engines (mixed with water around 50/50) to provide extra boost and cooling at high power settings.
For Australian users, methylated spirits which is a mix of ethyl and methyl alcohol will do the same job.

 

When I removed the hoses to the injectors, the fluid inside was mostly water, I would estimate more than 90%

Having fitted new hoses and clamps and a new fuel filter, the car started and ran normally again. So it seems the water settling to the low point in the feed was preventing it from starting before.

I returned to the fuel station and complained about the water contamination. They ran some tests on the storage tank using Kolor Kut water detecting paste but it was inconclusive. They said nobody else has complained. I don’t think I will hear any more from them but they took my number and said they would let me know if anyone else did report a problem. Fresh fuel dispensed from the same pump came out clear.

 

how much meths per gallon or litre please 🤙

 

re meths
You would be safe to go to 10%.-15%
100/150mils per litre or 1 pint per gallon.
Another way would be to use petrol with 10% ethanol.
cheers