does anyone know on an,84 xjs can i get rid of the small expansion tank under battery tray or do i need that for some reason.is there a reason for it??

 

You have to keep it. Because the main tank is wide and flat, once it is less than about 1/4 full, on a briskly taken corner the fuel outlet to the pump will be starved and the car will miss, and the pump will be damaged. The less fuel, the more it happens. The tank is often called a "swirl tank" in other applications, and its purpose is to ensure the pump and thus the injectors, have a good source of fuel even when cornering fast or when fuel levels are low.

It can be replaced with a different design, but having the same function; but what is the point?

Greg

 

ok then ill keep it it makes sense to me know as to what its purpose is thanks..one more thing.i noticed a vacum line with what looks like a small plastic black filter of some kind in line.comming out under batter by small gas tank its not hooked up any ideas what and where it goes.thanks

 

Hmmmm.

Sounds like the vacuum hose that goes to the ECU. It has a black filter cannister.

The ECU is behind a panel near the RH trunk lid hinge, roughly speaking. If it doesn't have a vacuum hose attached, there's your answer!

How is the engine running? It'll run poorly if the ECU vacuum hose is off!

Cheers
DD

 

I bought the car not running.it turns over.car sat for 3 or 4 years so i drained fuel tank and cleaned small tank out bought new fuel pump.and fuel filter.chaned oil and filter.and new battery.i got car from orig owner.all electrical works.i want to get it running i hope.i see ecu in trunk hooked up.also another one loose in trunk. ill check the one alteady hooked up and see whats up with vacum hose not attached.thanks for info.

 

jagernut - Any updates ?

 

Battery tray should also have a drain tube.

 

Sorry,I forgot about this thread.Yes all issue's with tank are corrected.Thanks for the help.I have car running and sounds pretry good.
If i knew how to close thread I would
thanks again.