Since buying my XJS several months ago it has an intermittent fault where the engine occasionally stalls, although the engine runs nicely.
Also on my to do list I have a couple of leaks, a bit of engine oil and I think Power steering fluid as the bottle was empty.

Anyway I have now noticed that this stalling problem is a fault I can create myself because I realise it's when I'm parking in tight spaces and turning the steering wheel on to say full lock and then trying to reverse. The tickover will drop and engine stalls. If the engine doesn't stall and then I turn the steering wheel the other way and try and move then it probably will stall then.

I'm now wondering if this stalling problem is to do with the power steering and the leak or is it coincidental but as I can now make this happen myself and looking on the internet I'm beginning to think the problems are related.

Any advice is gratefully appreciated.

 

My 1st suggestion would be to raise the HOT idle speed. If that is an unknown procedure, NO problems, ask, and I and/or others will give you the quick, and I mean quick way of doing it.

BUT

This may , and may not open up other issues, mainly a dicky AAV unit.

The steer pump, very OLD school thing, will put a HUGE load on that engine at FULL lock, especially when trying to get "that little bit more" wheel turn, which of course cannot happen, so the pump loads up, and stalls the engine.

Stale steer fluid also puts extra load on that system, but since you have a leak, I doubt the fluid is stale anymore.

 

Thanks for your reply. I think idle is fine. I did have it adjusted and the mechanic said the engine was fine but at that time I didn't discover the stalling only really happens when parking etc.

I think the AAV is ok because when cold it ticks over high and then adjusts but please let me know how to adjust the hot idle just so I know.

I do think though it's steering pump or fluid leak related.

 

Youhave done well with diagnosing the issue, congratulations.

The HOT idle is adjusted with the 13mm hex headed bolt looking thing on the side of the AAV. Easily seen and accessed.

With the engine at normal temp, or very close, turn that Hex ONE flat at a time, wait about 15 seconds before moving it some more, just to let the engine settle in.

I aim for 750 in P or N, without A/C etc on. Mine all drop to about 650 in D, and then 600ish with the A/C on.

Another very common cause of stalling is teh notorious V12 Black Goo that gathers inside the throttle bodies.

Again, an easy fix.

Pop the air filter elements, engine OFF, open the throttle by hand and with a solvent (gasoline if nothing else) soaked rag, wipe out the inside of each throttle body, and the Brass disc.
If this the first time, it may be thick and crusty, DO NOT scrape in there, just keep at it until nice and clean.
I do all my V12's at each oil change, and it takes seconds now the crusty stuff is no more.

Good luck.

 

Thanks

The AAV was already tweaked but will check again and will certainly check throttle bodies.

No A/C at moment as when I bought the car there was no belt on it and we removed the compressor to fix a water leak and haven't bothered putting it back yet as probably will change plugs.

I assume the A/C probably doesn't even work and when it does might even pull the engine down even more.