Right, here's the story, maybe someone can come up with a possible suggestion ............. Please

The Jag was over at the Paragon workshop, to have the front end corrosion sorted out.
Prior to this, it would turn over and start every time.

Due to corroded hydraulic connections on the gearbox and the gearbox oil cooler, mounted besides the engine radiator the gearbox had to come out, to have it stripped down and the connectors changed.
The gearbox then went back in and the engine started, to allow the gearbox to reach temperature as per the filling procedures.
All well and good ..........

I then received a rather panicked phone call from Tony M yesterday (Friday) to say that the engine wouldn't crank over, just the solenoid 'click' and nothing else, plus he didn't have a spare starter motor. I did, so I shot over there with the spare motor, to assist with the starter motor swap and to see what was going on.
Once we had swapped it, the car still refused to crank. After a lot of thinking and head scratching, it transpired that the engine to gearbox earth strap hadn't been re-connected, after changing the starter motor.
Strap on and the car started fine and was taken on a 10 mile test run, stopping the car once and re-starting it ........ All OK.

This morning (Saturday) I went over to collect the car and you've guessed ........ It wouldn't crank over.
So the engine to gearbox earth strap was taken off completely, cleaned and replaced, but it still refused to crank over.

A lot more questioning went and head scratching took place and Tony M said that he had removed another pair of earth cables from inside the engine bay, so that the engine bay could be re-sprayed.
I then set about taking the bolt and earth cables off, to find some paint on the earth pad. this was cleaned back to bare metal and a 'star washer' put between the earth pad and the two earth cables, followed by the nut .......... Bingo it turned over and started.

Again, we took the car for a spin. stopped and re-started it again with no problems at all ............ Sorted .......... I thought .............
I then set off for home, stopped for some fuel along the way, started the car again and arrived home, where I started to clean it, in readiness for a weeks trip to France.
I even started it again, midway through the afternoon and it started fine.
Now, back at home from the pub for a pie and a pint or two for dinner (9:30 pm) I tried it again ......... No joy It just dimmed all the cabin lights and refused to crank over.

So, what the hell is going on.
Prior to removing the gearbox, and the majority of the components in the engine bay compartment all was fine, now I have an intermittent cranking problem and it's DRIVING ME CRAZY

Any suggestions please.

 

I've moved your post from General Tech Help to XK8/XKR forum. This is the place to post technical questions about your model.

Graham

 

Thanks Graham,


Sorry, I've had a bad couple of days, trying to sort out this problem and what with the trip to France coming up tomorrow, I've got a few things on my mind.


By the way, the battery connections are as clean as a whistle and snugly tight. The battery has been on charge for over 8 hours and is showing 'fully charged' on the CTEC charger.
It's not an inhibitor problem either, as is does energise the starter solenoid, it just won't crank the engine (sometimes)
I know this, as I tried with the gear lever in drive ....... Not even a click ........ It stops the whole starting circuit.





Tony

 

I had a similar problem with my 98 xj8. Sometimes it would start and other times it wouldn't. It turn out to be the false bulkhead. I replaced it with one from a donor car and haven't had a problem since then. I don't know where it is located on the xk8 but on the xj8 it is at the box in the engine compartment that has the computer modules. I'm not sure but if you follow the starter power cable it should take you to the bulkhead. I would check it now but it's midnight here. Wiring diagram attached.
https://www.jaguarforums.com/forum/a...main-power.pdf

 

Thanks RobRoy,


I'll certainly check into that one.

I've also just been informed that there's a gearbox to chassis earth strap on the driver's side (UK) of the car.
Another thing to check if it was replaced correctly ......... Is it accessible using a hydraulic jack, or is it a 2 post ramp job?




Many thanks
Tony

 

Tony,

Another one to check - High Power Protection Module (see item 5) connections.



The cable terminals are known to loosen and/or corrode leading to starting difficulties. The remainder of the electrics work but there's not sufficient juice to operate the starter.

Graham

 

There is only one èarth strap and it is located here in the US on the passenger side. I thought you said in your original post that you checked and cleaned the connection. It is accessible by jacking up the car.

 

Right, it looks to be sorted .......... I had a long chat with Tony M. and he gave me some extra pointers to check, none of which were the cause of the problem, but whilst I had the TB to air box induction pipe off, I came across another earth point, with a battery size earth cable and a smaller earth cable going to it ............ It was loose, with obvious arcing marks

Once tightened, the engine sprang into life ......... Although I will re-check the starting a few times this evening and also tomorrow morning, prior to the 24 hour cut off point to change vehicle details on Le Shuttle.
Also because I don't want to be stranded on the Shuttle or a hotel car park or even a fuel forecourt, with or without fuel

By the way, there isn't an engine to gearbox earth strap, so the strap I was describing earlier, was the gearbox to chassis strap and that has already ben inspected and is OK ... ish.
I've found a company on e-bay, who can manufacture a now one for me ....... Just in case, way cheaper than a Jag part.

Thank you for all your assistance .......

 

I have never seen a transmission to engine ground. With the transmission bolted to the engine it wouldn't need a ground strap.

 

It crossed my mind it was a brave decision to go to France this week!

Good to hear you found the loose connection.

Graham

 

Graham, I will look into Tony's solution to maybe solve my own. I just don't get squat with the key on.




Wayne

 

Quite correct RobRoy, as I said above, I was mistaken.
When I was laying on my back, in a very cramped position trying to change the starter motor, I quickly noticed the earth strap and it just looked like it went from the gearbox to engine, whereas it was actually connected to the body.

 

I've now started the car over 6 times this afternoon and each time it cranked and fired up immediately, so I'm gaining confidence by the hour.
A few more tries this evening and a few more tomorrow morning and I'll be ready to set off.


What did it for me, was a definite large earth cable, which had to be starter related and was loose, plus seeing arc marks on the connector was confirmation that I'd found the culprit.


Happy days, or should that be; Le happy days.

 

With yours Wayne, I'd say immobiliser, starter relay, fuse, faulty starter motor or broken wire to the solenoid.
Mine definitely was seeing some voltage; enough to energise the solenoid but not crank the motor .......... Good luck with your search.




Tony

 

You may already be aware of this and are taking steps to ensure it does not occur in the multiple start/stop cycles that you are putting your car through. But, are you taking into account the possibility of 'cylinder wash, or bore wash'? This could be a concern if you are starting the car and then immediately shutting it down, without letting it warm up sufficiently, and drop to a normal idle. Just and FYI, would hate for a new symptom to appear that is not at all related to the starting problem, but can be caused by starting/stopping the vehicle to check if it still starts.