2000 Sovereign V8 - Will not start??
Discussion
Can any one give me some pointers, my Sov has suddenly failed to start? previously running 100% no errors on scanner when plugged in, cranks over and fires with easy start but will not continue to run, been told you need neither fuel or ignition for 'easy start' to do this.
Any ideas??
Cheers
Danny
Any ideas??
Cheers
Danny
How does it crank over? At the usual speed with discernable whump whump whump compression strokes or at much higher speed and sounding like a washing machine on it's final spin?
If it's the former then you probrably have a fuel or ignition issue which should show up with a scan and the latter suggests a loss of engine compression which won't.
Loss of compression may be due to flooding and subsequent bore wash or Nicasil bore lining failure. V8s can flood if started from cold and then stopped again before they have been allowed to warm up. Nicasil failure on an V8 is very unlikley now but might just become apparent on a already affected engine with a combination of extremely cold temperatures and flooding.
There are two methods of starting a flooded engine. The first involves heavy duty jump leads and a substantial spare battery and continuous cranking for several minuites whilst modulating the throttle. You need to remove the fuel pump fuse and have an assistant put it back in when the engine shows signs of developing compression. I wouldn't do this as IMO it's a bit barbaric and puts tremendous strain on the starter motor and electricial system.
Ths second involves removing the spark plugs and drying them off, putting a squirt of engine oil down each plug hole to restore the oil film on the bores, replacing the plugs and starting normally. This is what I'd do.
BTW - Up to you of course but I'd never use Easy Start on a petrol engine. It'll just make any loss of compression issue due to bore wash even worse and you're running a significant risk of causing a crankcase or induction system explosion if any concentration of flamable gas builds up inside the engine.
If it's the former then you probrably have a fuel or ignition issue which should show up with a scan and the latter suggests a loss of engine compression which won't.
Loss of compression may be due to flooding and subsequent bore wash or Nicasil bore lining failure. V8s can flood if started from cold and then stopped again before they have been allowed to warm up. Nicasil failure on an V8 is very unlikley now but might just become apparent on a already affected engine with a combination of extremely cold temperatures and flooding.
There are two methods of starting a flooded engine. The first involves heavy duty jump leads and a substantial spare battery and continuous cranking for several minuites whilst modulating the throttle. You need to remove the fuel pump fuse and have an assistant put it back in when the engine shows signs of developing compression. I wouldn't do this as IMO it's a bit barbaric and puts tremendous strain on the starter motor and electricial system.
Ths second involves removing the spark plugs and drying them off, putting a squirt of engine oil down each plug hole to restore the oil film on the bores, replacing the plugs and starting normally. This is what I'd do.
BTW - Up to you of course but I'd never use Easy Start on a petrol engine. It'll just make any loss of compression issue due to bore wash even worse and you're running a significant risk of causing a crankcase or induction system explosion if any concentration of flamable gas builds up inside the engine.
Turn ignition off and PUT THE KEYS IN YOUR POCKET. Don't leave them in the ignition incase you trigger the central locking 
or fry some module whilst faffing about with fuses...
Check all the fuses in the smaller of the two (engine management) fuse box under the bonnet.
Swap relay 7 in the larger of the two fuse boxes under the bonnet round with another brown one from the same fuse box
In the boot fuse box by the battery check fuse 7 - fuel pump.
Go right through all the car systems and make sure evrything else works - often you'll find another random fault that gives you a clue to where the original one lies.
ETA Check the fuel cut off inertia switch as well - just to rule it out. it's behind the carpet in the drivers footwell on the right hand side. There's a button under the flexible cover on the top. Push down to reset
or fry some module whilst faffing about with fuses...Check all the fuses in the smaller of the two (engine management) fuse box under the bonnet.
Swap relay 7 in the larger of the two fuse boxes under the bonnet round with another brown one from the same fuse box
In the boot fuse box by the battery check fuse 7 - fuel pump.
Go right through all the car systems and make sure evrything else works - often you'll find another random fault that gives you a clue to where the original one lies.
ETA Check the fuel cut off inertia switch as well - just to rule it out. it's behind the carpet in the drivers footwell on the right hand side. There's a button under the flexible cover on the top. Push down to reset
Edited by Jaguar steve on Monday 11th February 09:09
You can't think of anything you might have done or anything that's changed over the 4 days? Not using a different key, or flattened the battery and disconnected it to recharge perhaps or has it got wet or flooded and now dried out?
Intermitents are the worst of all and I can't think of anything else to suggest atm - you could throw lots of time and money at it chasing imigainary problems but if you do that you still won't know if it's actually fixed unless you really do find something wrong. And even if you do you don't know for sure that's the only thing.
The one advantage you have compared to taking it a garage is time to observe and think about possible causes and effects. You could usefully spend a couple of hours checking all the fuses and electricial connections you can see and making sure everything else works as it should. You also have a scanner which may help find the cause if it happens again.
If you can I'd drive it in a "safe" way. If it's not always starting but runs fine once it does then just do round trips and only switch off where it's OK to leave it. That way you'll buy some time to gather more clues about how intermitent the problem really is and put you in a position where you can rule out things like a blocked fuel filter without the massive grief of a dead car miles away from home.
It could be a faulty crank sensor perhaps - quite common on the earlier X300, or failing immobiliser or fuel pump or a bad connection somewhere - finding the fault is the tricky bit, fixing it is a doddle by comparison.
Intermitents are the worst of all and I can't think of anything else to suggest atm - you could throw lots of time and money at it chasing imigainary problems but if you do that you still won't know if it's actually fixed unless you really do find something wrong. And even if you do you don't know for sure that's the only thing.
The one advantage you have compared to taking it a garage is time to observe and think about possible causes and effects. You could usefully spend a couple of hours checking all the fuses and electricial connections you can see and making sure everything else works as it should. You also have a scanner which may help find the cause if it happens again.
If you can I'd drive it in a "safe" way. If it's not always starting but runs fine once it does then just do round trips and only switch off where it's OK to leave it. That way you'll buy some time to gather more clues about how intermitent the problem really is and put you in a position where you can rule out things like a blocked fuel filter without the massive grief of a dead car miles away from home.
It could be a faulty crank sensor perhaps - quite common on the earlier X300, or failing immobiliser or fuel pump or a bad connection somewhere - finding the fault is the tricky bit, fixing it is a doddle by comparison.
Edited by Jaguar steve on Monday 11th February 11:22
That's what I have it listed as to. Did you clear all the faults and then have this one come back since you got it started? Clear it again and keep checking if to see if it comes back.
I'm not clear about exactly what that means but it might be worthwhile having the fuel rail pressure checked. If I had to guess I'd suggest it may be the fuel pump is drawing too much current either because it's failing or there is a restriction somewhere in the fuel system. There is a Schrader valve on the fuel rail on the left front side of the engine you can plug a gauge into. IIRC somebody has posted a Utube video showing how this is done and how to replace the pumps on an XJR. As an outside guess it could just be you have a partially blocked fuel filter, these are cheap enough and not difficult to change so it might be worth doing just so you can rule this out.
Think it's worth rechecking all the fuses and relays I suggested earlier too - sometimes just removing and refitting will clear corrosion on the contacts that may be causing a problem.
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