Here is the quick story. Found a one owner BRG 89 XJS with power sunroof ! The cars owner was now 94 years old and the car had been left sitting in the garage for several years.

I did manage to get the car started briefly once I got it home. It ran poorly AAV was stuck so it was idling high. I did not run it long since I was just verifying it would run before changing fluids and so on.

So I changed the plugs NGK new wires cap and rotor where just cleaned up as they looked good and I can’t seem to find good mareli replacements.
changed the oils and filter as well. Repaired the Aav and replaced it’s hose and gasket.

well unfortunately I put it all back together and it started but still didn’t run well. High idle followed by low to high idle. After fiddling with it checking for vacuum leaks and so on eventually it refused to even start.
pulled a plug and it was black and fouled.

so tonight I pulled all the plugs cleaned them out them back in. FUN stuff !

this isn’t my first car resurrection so I’m familiar with the obstacles here but looking for tips as I have only owned one xjs and not for very long.

I am thinking I need to drain the old fuel. I have had old fuel foul plugs like this and give me endless issues.

any other thoughts ?

 

When the AAV is stuck and it revs high enough ( 1500 I think) the ECU cuts fuel until the revs drop, then it picks back up because there is too much air and the cycle repeats.

There used to be AAV rebuild kits available, but not any more I think. New ones are still available from Jaguar, but are very expensive.

I would start by getting fresh fuel in it and then change all the other fluids and go from there. Probably tires too.

 

Yes on draining old fuel.

Also pull the fuel filter and empty the contents in a clean jar. What you see (or don't see) might dictate your next steps.

A crudded-up fuel system is a distinct possibility.

Cheers
DD

 

A few bottles of Chevron Techron will help with that.

 

Second.

That stuff is paint stripper for fuel systems, be prepared to replace both filters shortly after use, your injectors themselves may have the filter basket clogged... Your position sensors will be highly suspect at that age.

Your 89 so likely marelli if so ensure high octane timing map is selected, and your using the maximum available high octane gas.

Come to think lf it the list could be extensive, but all relatively minor items.

 

high octane timing map is selected ?

where is the filter basket located ?

 

Welcome and good luck. My 88 sat for 4 years so maybe not as long as you, tank was basically empty. all I did to get it started was change oil and put in 5 gallons of 91 octane (thats here in Canada) with some octane booster to make it 105 , fuel injector cleaner and fuel stabilizer. Surprisingly once it fired up and ran for 10 minutes it actually ran pretty well. Not perfect but enough for now until I tear into it.

How much fuel was in it? If more than 1/8 tank get rid of it. Then as recommended cleaners etc. The injector filters are inside the injectors. I think living with a classic on youtube did a rebuild video. If he didn't there is some. I plane on rebuilding it. There are kits out there that comes with everything you need.

I have a lucas system as mine was built march 1988 so can't help with that stuff.

Any more pics of the car?

 

Might help.

Jaguar Auxiliary Air Valve

 

Check the coolant temp sensor. If it goes bad the engine will not run. You can jump it to test it but it's cheap and easy to replace. My '89 is not the Marelli ignition system system so I guess that it's an early model. Best of luck.

 

Success she is running pretty well. It was a combination of things. Aav stuck was one. Fixed that. Some vac leaks. Bad gas fouled my new plugs so had to pull them all and clean them. Drained gas and so on. Any way I’m pretty happy with the result so far.

 

 

Great work !

Cheers
DD