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Intermittent none start
Posted: Sun Apr 16, 2023 9:20 pm
by ng4xjs
This is an interesting one. Very occasionally I get into the car having driven somewhere without any issues only to find it won't start on my return. It's just that everything is "dead" no clicks or clunks. Walk around the car get back in and everything is okay

. I did tighten up the battery connection posts but can't for one moment believe it to be this. I'm running a Bosch battery some three years old so don't believe it to be that. Any ideas, suggestions warmly received.
Kind regards
Nick
Re: Intermittent none start
Posted: Mon Apr 17, 2023 12:10 am
by ptjs1
Nick,
Check the integrity of the wiring on the ignition switch.
Paul
Re: Intermittent none start
Posted: Mon Apr 17, 2023 6:27 pm
by andypryce
And earthing points.
Re: Intermittent none start
Posted: Tue Apr 18, 2023 11:19 am
by PaulGover
Do you have an immobilizer/alarm system? I had similar issues with an aftermarket immobilizer on my car. The problem turns out to be the electric door locks not always sending the right signals to the control gubbins.
Re: Intermittent none start
Posted: Tue Apr 18, 2023 9:07 pm
by ng4xjs
Thanks All - I'll take the steering Coolum cover off at the weekend and check the integrity of the wiring. I don't have an immobiliser so can rule that I hope. All I can say is it happened once about 12 months ago and again twice last week, all at the same shopping centre (close to where I live), coincidence? I did tighten the battery terminal posts connections but careful not to overtighten! Hasn't done it since.
I'm afraid I've let my care slip a little this last year, probably due to getting old and the car not getting much use. Jobs are mounting up. Top and bottom ball joints (due principally to torn gaiters). A bit knocky front suspension due I believe to shock absorber top mounts failing (I have a new set so an easy fix. I think I can just undo the header tank retaining bolts to give enough clearance on the off-side rather than draining it. Finally still need to isolate the short on the interior lights which without the fuse disconcerted remain on and lead to a dead battery. Apart from that all good.
The bottom line is that as we all do, I really love driving it. Such a special car.. At the moment I'm trying to persuade my wife that we do of course need to keep two cars (being an older person about to retire albeit well past NRA).
Happy days
Nick
Re: Intermittent none start
Posted: Mon Apr 24, 2023 11:43 am
by SimonR
At the moment I'm trying to persuade my wife that we do of course need to keep two cars (being an older person about to retire albeit well past NRA).
That's an easy one, Nick - my parents (in their mid 70s) have this one sorted out, I'll share in case it's of help.
Many years ago, my dad bought himself a 3.4L 1977 Daimler Sovereign XJ6 as a second car as he'd always wanted a Jag and could finally just about afford to run one. Times changed, and this got replaced by a 3.0L 2001 S-Type, which my mother then decided was far nicer than what she was driving so she adopted it. Dad felt hard done by and, with the help of a retirement lump sum, bought himself an XK8 to replace the Daimler about 10 years ago, but the problem was then that they then needed a run-about for trips to the tip and general shopping etc., so they also now have a no-frills Volvo estate...
What I'm saying is that if you and your wife have two Jags at the moment, the only logical step for you is to buy a third car

Re: Intermittent none start
Posted: Mon Apr 24, 2023 5:34 pm
by davidr
Some years ago my wife and daughter thought it was very amusing to call me "Two Jags". I think they thought that likening me to John Prescott would have the desired effect. It did indeed spur me to action - I added an X350 to the collection!!

Re: Intermittent none start
Posted: Thu May 18, 2023 6:38 pm
by ng4xjs
Still trying to get to the bottom of this. Starts perfectly all week and then refuses to turn over. replace the key and try again and usually bursts into life after third or fourth attempt. Wiring integrity is okay. It feels like a "flat battery" and sometime notice charging above it's normal 13 volts. It seems like a current draw somewhere? Battery is good. I'm sort of inclined to a "starter-motor/starter solenoid issue.
On a slightly more positive note did replace the front shock absorber isolator bushes earlier with the up-rated ones.
Happy days
Nick
Re: Intermittent none start
Posted: Fri May 19, 2023 8:21 am
by andypryce
If ignition and everything else lights up ok then agree likely starter motor or solenoid.
Re: Intermittent none start
Posted: Thu May 25, 2023 8:52 pm
by tommad
For me, what sounds like a similar problem seemed to be the starter relay. Cleaning the contacts of this helped and then I had it replaced and that problem seemed to have been resolved.
Tom
Re: Intermittent none start
Posted: Sat Jun 24, 2023 7:24 pm
by ng4xjs
I cleaned but haven't replaced the starter relay. I do have a spare and will try that tomorrow. Car had been performing well for the last few days and then today and embarrassingly refused at my local petrol station

I had to resort to the old crocodile jump lead from the bulkhead live feed (the one to the starter motor) to the exciter wire on the solenoid, but at least it gets me going.
I do have a new replacement "starter switch" (SNG) but looks a bit messy to swap over. That said I'm thinking it is the starter solenoid after all because of the intermittent nature of the fault. I think I take the view that were it the switch it would be most of the time. I also came across some damage to the white/red wire sheath from the low voltage solenoid back to the relay although no damage to the integrity of the wire. Whether by coincidence, but the first start of the day from a relatively cool garage is (so far) 100%. I do have some serious motoring coming up so would like to find a proper fix.
Nick
Re: Intermittent none start
Posted: Tue Jul 18, 2023 7:51 pm
by ng4xjs
Finally sorted. The issues turned out to be a faulty ignition switch not helped by a slightly corroded starter relay. Incidentally the starter relay is the middle one of the three under the cover on the right side (RHD) drives side and not the one nearest the bulkhead (various wiring diagrams etc.), that is for the horn. Job done (fingers crossed).
That just leaves the drivers side heater blower motor to sort. Would be good if this climate change global warming is going to be with us.
Nick
Re: Intermittent none start
Posted: Tue Sep 12, 2023 7:29 pm
by ng4xjs
Oh dear not finally sorted after all and continues to be an incredible annoyance. So far I have replaced the ignition switch, starter relay and Starter motor. All wiring checks out as far as I can tell. First start of the day, absolutely okay, starts instantly and then it might again if the engine has not warmed up. Then, not a hope.... and back to the solenoid to live terminal on the bulkhead trick. Sort of amusing in the supermarket car-park with on lookers wondering.
But I cannot for the life of me work this out. I think the bit I'm stumbling with it is that it starts no problem from cold and then doesn't. It surely must be a continuity issue between the relay and solenoid? Or is there an ECU I'm not aware of perhaps. Help!!!!
The car is just generally fighting back at the moment. Today the central locking failed. Boot and passenger door unlock on the key but drivers door just will not lock. Thought fuse and sure enough. Replaced and all fine but then notice fuse was glowing like a bulb so pulled. I'm guessing a failed actuator in the drivers door. Key just wont turn to lock (or the inside catch).
Happy days
Nick
Re: Intermittent none start
Posted: Wed Sep 13, 2023 7:38 am
by ptjs1
Nick,
A couple of thoughts:
Have you fully checked the starter relay holder and linked wiring? It does sound like a continuity breakdown when hot. Also check the bulkhead earth and positive terminals. Maybe undo and thoroughly clean them.
As regards the locks, the drivers lock can be prone to gumming up and needs multiple sprays to clean it out. When it gets gummed up, it can tend to overload the solenoid actuator which burns out. Also check the tension of the link rod from the internal lever rod as that can cause the same problem.
Cheers
Paul
Re: Intermittent none start
Posted: Wed Sep 13, 2023 7:19 pm
by ng4xjs
Thanks Paul - That's my weekend sorted then
Best wishes
Nick