Well, the saga continues with not much done to the old cat this week except...

Had to pop out and get James the Siamese cat some cat food, his hungry wailing could be heard whilst I was outside tidying up my workshop, so what better to take than the X300.

The Jag had been sitting for a day and took what seemed like an age to start even with the 4 second wait, started very fluffy but then drove off with no issues. Got to the village shop and locked the car and the central locking bounced three times....been here before when the battery was getting low and put that down to lack of use.

She started OK though for the return journey....I thought but could not be sure that I heard a alarm beeping coming from the area my car as parked but this stopped before I got to the car....????

On getting home (and feeding James...) I checked the charging on the battery at idle with headlights on mainbeam, heater blower on full, heated front and rear screens on and she came back with 14.3 volts at idle. I then checked the battery for 'residual' charge and it was again low....it seems the battery is loosing charge.

Battery left overnight to charge.

Went to start her this morning and she started straight up on a fully charged battery, and I do mean faultlessly!

I think it was hinted by Sparkenzap (sorry if I got that wrong) in another post that maybe the battery could be at fault for causing the bouncing locks and that X300's need a 100% perfect battery or strange wizardry can occur....possibly a poor start?
It's a decent Exide quality battery, the correct rated battery, looks fairly recent although the vendor made no claim to have fitted an new battery so could be over 1 year old..... unless I have a battery drain going on I beginning to think the cause could be the battery just starting to fail in some way internally....the batteries cranking power can't be faulted though.

Not much to do other than fit a new battery and go from there and I'll chime back.

cheers guys

 

One of the problems with the battery being in the boot is that being isolated from the engine bay, it always tends to look like new, and is very difficult to assess visually. (there are positives arising from not being in the engine bay too) You will see a number of threads on here where the solution to a wide range of faults has been traced back to a battery being below par, and in the case of the X300, below par would seem to be anything below about 95% of perfect!
The engine is harder to crank when the oil is cold, and your scenario could be explained by the battery voltage initially falling below threshold for the various electrical systems until the starting load reduces after the initial cranking of the engine.
Whether this is the cause, and whether the battery is faulty or being drained is difficult to determine at this point, but it might be worth leaving it on a battery conditioner overnight for a while to establish whether it does continue to start faultlessly.

 

Arrgh, just started her this evening with topped up battery, took ages to start very fluffy and have an off-idle single cylinder misfire now ....I'm gonna have to pull those injectors for a looky see I think?

....excellent quick 'n dirty fuel injector test, this is the guy you need in a 'Flight Of The Pheonix' situation!

 

The X300 can be very fussy about batteries that are not giving full voltage, do you have another you can try? If it's more than 4 years old I'd just replace it.

 

Quick update in case anyone has the same issues....she has been consistantly bad at starting from cold being fluffy when she first fires.

OK, fitted a Noid light today to number 1. Now being a Jaguar this isn't as straight forward as could be as the whole cable to injector connector block for all six injectors needs to be lifted to gain enough access for the Noid light, I used the Bosch light in my kit.

Connected the fibre optic extension cable and then turned the engine over....pulsing LED light showed straight away but also the car started and ran for just a moment, only a fleeting moment but it did fire...spookey!

Connected the injector cable block back up and she fired instantly again.

...its always great fun to speculate on a forum so here goes...

...I think I may need to pull my injectors, possibly I have the opposite of what I thought maybe happening, being a lack of fuel in the fuel rail, its maybe too much. It could a leaking injector (s) hosing into the manifold over down time, its the only way I can explain a momentary cold start when a very rich fuel mixture is required with only the plugs firing at the moment? Strangely, though possibly not, no black smoke when she starts eventually starts.

There is no 7th cold start injector in these systems.

 

The X300 is fairly rich upon starting, that's quite usual. if you do a series of starts and stops, i.e. start the car, back it out of the garage and park on the driveway and shut it off, of do a pair of short starts and stops like that I have had it flood and not restart until I pulled the plugs and dried them.

As mentioned, the ECU is also very fussy about low voltage in the battery. It may test ok, and seem alright, but if there is a significant voltage drop on cranking you can get all sorts of weirdness. Many X300 problems have been cured by a fresh battery.

Your door lock problem is caused by a sticking microswitch in the drivers door lock actuator assembly. Replacement is the only cure I'm afraid. Been there, done that...

 

New battery fitted, now have a great spare though still had door lock issues with new battery...
but the door locking issue (cental locking bumping 3 times) is now now resolved, I was lucky was just a WD-40 clean up of latches and fixings and a bit of use....but I'm sure something else will pop up to raise an interest

I'll chime back when I've pulled my injectors for a lookysee

 

It sounds very much like leaky fuel injectors, causing the plugs to get wet. I've seen many x300's and late XJ40's do this. Try taking the spark plugs out in the morning and see if they are wet or smell of petrol. The fuel pressure regulators have also been prone to failing, but I would be leaning more to the injectors. You can try to run some cleaner through or have them cleaned in an ultrasonic bath, but may have to replace with new. Hope this helps.

 

Yes that's my next job, but weather here is either..snowing...frosty....raining..delete as necessary.

..I hope you mean pull the plugs after cranking for a few seconds, not before cranking....if it was leaking that much fuel along and down inlet manifold and filling the combustion chamber I'd have hydraulic lock...just kidding.

You know I did once have a late XJ-40 with similar problem that I lived with. I also see mentions of poor cold starting and interesing that you have seen this before. These old Jags spend too much time sitting around and with modern fuels this can't be a good thing.

I had a Vectra recently with 'varnished' injectors, one was so bad it caused a low speed misfire.

....the plot thickens as they say in all the best mystery novels

thanks for the help

 

Well from my experience, I've taken them out before cranking. The fuel pressure should not completely die off overnight, so if the injector leaks, the plug will most likely be wet if the injectors are leaking. Maybe it's also that it takes a few cranks for the fuel pressure to build up? Have you checked fuel pressure while cranking?

 

There is a hole in the market for a an easy fit X-300 and XJ-40 fuel pressure take off port....

I may look into doing this, its frustrating having the pressure tester but nowhere to fit it, they are a very useful diagnostic tool.

.....you know thinking about it I can't think of another car I've owned without a fuel rail pressure test point/relief valve, when fuel injected?

cheers

 

I can't come up with another without a port on the fuel rail to check pressure either. I've seen a lot of guys make their own, might have to do that, don't think an adaptor is available in the tester kits.

 

Quick update on the bad cold starting, before I pulled my injectors as I'm still not convinced they could cause a bad start and then run fine when hot...of course I could be wrong but hey...so I took a 'tip'

1/ I took a 100% dead cert 'tip' from a Jag expert regarding my bad cold starting issue....and fitted a replacement camshaft position sensor

TDC on correct revolution found by looking at number 4 inlet valve lobe under the oil fillre cap in 'up' position, engine crankshaft sensor 'in' the gap of the 'timing wheel' ...camshaft sensor in the correct position and.......no different....or the replacement is faulty, I did go used so possibly.

Unless I had read it wrong, thinking about this the accepted 'form' is that even if the camshaft position sensor is fitted in the wrong position the engine will after turning over a number of times sort its self out with regards matching the crank position to the cam position....does it?

If the camshaft position sensor is timed incorrectly and the engine tries multiple firing order positions before it starts' then why doesn't it misfire when sorting its self out?

And why would this only effect a cold start....how could the ECU memorise the camshaft position only to loose it after 30 mins or so?

2/ I bought a spark tester, only a few quid and a useful tool in the armoury. So I fitted the tester to a cold engine thinking I look to see if I'm missing a spark when cranking and hey presto as usual the car started first time...healthy spark from the off....this car is taunting me!

3/ My mechanic had an interesting off beat thought....coolant temperature sensor failure...so I shot him down in flames telling him my real time data tells me it's working OK and if I pull the sensor I get -40c but....
....he likes to do technical courses and recently did a Snap-On diagnostic course and learnt that 'sometimes' the real time data for OBD isn't as real time as it could be for things like coolant temp'...he can't remember the car in case though...the lesson was to never assume and backprobe everything that can be.

so onwards and upwards we go with my coolant sensor in some hot water and a DVM

 

coolant temp sensor measures out OK....3.8k ohms at 10c sounds about right.

 

All injectors pulled today, tested using the carb cleaner, tyre valve and 12 volt source method....I gota say this car is Soooooooooooooo easy to work on compared to the modern stuff I work on.

No leaking injectors, all injectors spraying OK.

When keyed on no delay in fuel supply from tank.

All bolted back up and car started promptly.

search goes on.....CPS maybe next on the list....it's the original CPS by the looks of it and judging by the amount that go down on here maybe worth just keeping one in the boot for the day it fails!