Hellou, i was searching this forum for a while. and i got my first Jaguar last week XJS 1982 V12 HE. the car was standing in a garage for 7years . when i bring it to my garage i find some problems off course. after i start the engine first time it was running not so good and only on idle RPM, if i press the gas the engine die , i have checked injectors, spark plugs , distributor , all the wiring, also the TPS , and all seems good. but the pump is running all the time after i have the ignition on , so i found on the relay that somebody put in the bridge wire , after i changed the relay take the cable off nothing change. sou normally the pump is not working and its not running more than 600 RPM. only one thing to replace i am thinking of is the ECU. please guys does anybody had some troubles like this ? please help me , i want to be sure before i buy the ECU , thank you

 

Firstly welcome aboard.

When time permits please do an introduction in the "New Members Area".

Sitting for so long will have some serious things that need attention.

It runs, GOOD.

The fuel in the tank/s is highly suspect, even if you added fresh fuel, the "gunk" from whatever was in there will reek havoc. Drain the tank/s thru the drain spigot in the boot floor under the small sump tank. A rubber bung may need to be removed first, but it is there, and a little looking around will easily find it. Refill with some nice fresh fuel.

Change the fuel filter.

The pump should run for about 2 seconds when the ign is switched ON, and this is normal. The bridge wire is OK for the interim, whilst the sorting is carried out. Obviously a caution must be taken, as the fuel system is getting supplied whenever the ignition is ON.

What settings are you reading on the TPS at idle. Also is the TPS providing a nice smoooooooth rise in volts as the throttle is opened from idle to full. Any gaps in that rise is a dud TPS. You are looking for 0.34v to 4.8 approx. The high side is NOT critical, the low side IS.

Fuel pressure, AND flow is also on that list.

The ECU's give little trouble in the big scheme of things. That being said it may be faulty, but the fact the thing actually runs, I doubt it very much.

 

thank you, i have cleaned also that small sump tank. the TPS works perfectly like you write. and the car is not charging, the alternator is broken or some wiring, and i heard something about like it will not run without the charging. is it possible that the problem can be just that ?