Good morning, All.

I got back to messing around with the ol lady yesterday. Just to put it in the mix - this is a car that spent some time underwater in a fresh water flood.

Question is to do with the starter , cranking, and a good earth ground for engine to chassis.

After about 2 weeks I was able to get back over and do some work on the car. I connected the battery (new) and turned her over. She fired right up. Warmed up and idle went to normal. Turned off and restarted maybe 2 or 3 more times in messing around,, then suddenly no go. She wouldn't crank again. Many many key turns since, and no go. This has happened before.

Quick question. If I can use the relay, bridge it, and without fail get the starter to engage,,, everytime without fail, can that happen and there STILL be a no crank situation due to a poor or incomplete earth ground? Earth strap? Will bridging the relay work WHILE normal crank on key turn fails due to failed grounding?

If the started is bad,,, will bridging still work? Does bridging negate or bypass the use of the regular internal starter switch/solenoid?

I should add that in that first day back after a while, I did a LOT of manipulation of the roof, rear windows, rams and the roof latch at the top of the windshield. I have done several hard resets since - top up, latched,,, rear quarter windows up - but still she will not crank. CAN issue, maybe? Did I confuse the car,,, again?

Anyways,,, yup, my crazy *** again...
Any help is much much appreciated.

I am again haunted by issues with this car...

ps.... I​​​ did although get and relate/replace all of the butchered parts of the roof. Thanks to Jaguar Heaven!!! Great guys over there! Just needing a pump now.

 

I'm confused and I suspect it's just a matter of terminology. Many of us refer to cranking as the starter causing the engine to turn over, but not actually run, or fire. So does the engine turn over when you turn the key to the start position?

You say you did a lot of things with the roof, windows, etc. Did the battery voltage get to low? The ignition will be disabled if voltage gets too low.

 

Hey RJ... Thanks. Battery has enough charge and I have a good jumper just in case. Yes, in my fiddling, I have run the battery down before. With the battery as it is now, if jumper the starter relay, she will crank, turn over, the starter will spin the engine,,, nicely. Reliably.

On key turn she will NOT crank as described above. Starter seems to go right up to that point where she will crank and then no,,, Starter doesn't turn over or crank the motor at all with key turn,,, yes with jumped relay.

If there was a GROUND issue,,, would that ALSO show up and not crank, spin, turn the engine over when jumpering the relay?

 

How are you jumping the starter, external power or from a bulkhead connection? It's possible that the ground connection at the bell housing or the ground strap for the battery are faulty, but also the starter solenoid could be the problem.

 

I use a short stretch of wire (a jumper) placed between two of the slots that the relay uses to route voltage to the starter once activated. I bypass the starter.

What I'm wondering is (with an engine ground or grounding problem) whether or not jumping the starter WILL work to spin the starter motor while using the key switch WILL NOT?

The engine, hence the starter, is grounded via an earth strap found right under the area of the starter.

 

I don't think it's a ground problem. It may be that the ignition switch is defective. Does the instrument panel light up?

 

+1 with RJ. FWIW dont all starters ground themselves to / through the engine block? This would say ground strap is ok since the starter spins with you shorting across relay sending battery to starter.

 

Hi John

Yes. Starters and other things do,,, BUT,,, the engine block itself has to have a good solid ground itself. Hence the engine strap... If not, all kinds of things can happen, including no start no crank... Where you can actually light a test light if it's grounded to the battery and the probe end is touching the engine. Can make problems with the alternator too, from what I understand...

Like I was saying,,, sometimes the starter will fire right off and she'll start right up... Other times, turn the key and it just fails to turn over...

Of course I haven't ruled out other possible and worse problems. Nothing can hurt from me running a strap at this point. I was just feeling all BEFUTTLED with a somewhat disappointing run at working on the mean *** girl.

 

Hi Jay, no problem.

I was just saying that if you can get the starter to spin jumping the relay, it will be using the same grounding circuit as using your key, so I just wanted to directly answer your question about a possibility faulty ground strap so you can cross that off the list.

John

 

Hey Man, How ya been...?

Yeah, I get ya. And I was and am thinking the same. Things can be funny tho... I was thinking that because there is basically a shorter and straighter shot,,, direct line to the starter at the relay, that maybe had something to do with the difference... I think you might be right but you know me. Sometimes in denial...

I'm sure I get the "ok to start" because the relay clicks with 11 or 12 volts to the trigger side, but then the starter doesn't turn. If I bypass the trigger it will. And, some days/sometimes she just starts right up. I've swapped relays, still, nothing.

Really, this and the fuel pump PWM issues are the only thing holding me back. Got to get it figured out.

 

Jay, is it definitely the starter relay that clicks when you turn the key to crank position iii?

Reason I ask is that at position iii, the auxiliary circuit relay is de-energised, which might be what you're hearing? Do things sound the same if you remove the starter relay?

If the car always starts by jumping the relay output, it's not a security issue: could be ignition switch/wiring problem.

 

HellO Michael.

I could be wrong in calling it iii position... If I leave the DMM probes in the slots and turn the key, I get 12v (roughly) to the trigger side of the relay... Now you've got me thinking. I'm dumb, and did not (I was doing a lot of stuff) put the probes in the high amp side and test there. Honestly,,, I get boggled when it comes to electrical, and I am really feeling out of my depth - have from the beginning. I can't slow down and think and be methodical. I will make that check!

I also get a click at that relay in the driver's door fuse box on key turn,,, the aux circut,,, dash and cabin lights go out for a sec...everything seems right but, no crank.

And good point. The reason I haven't gone and gotten a starter,,, or even spent $$$$ on a damn ground strap, is because it will not start when I jump the relay. Only spin/crank. The starter picks right up and sounds healthy/strong when I bridge the relay. But, no start.

Crazy thing is, as much as it won't, it has and will start with key turn in the past. Usually if I leave the battery disconnected for a good period and in the past if I connected the negative cable to the positive for a "hard" reset...

It seems like there may be a few things going on with the CAN system that has got the car confused. I'm getting to the point where I am a getting a bit exasperated by this whole thing.

Between the damn PWM issue and now this. Sheeeeesh!

​​​​​​

 

Not clear what you mean by the trigger side? The B+ to the starter relay pin 1 comes from the TCM, and only in P or N - is that power consistently present with the shift in those positions? The relay is actuated by the ECM grounding pin 2. Presumably it only does so if the security checks out.

OK so you've clearly differentiated between the start & aux power relays.

I think for the moment the starter motor is exhonorated as it seems to respond whenever asked. The scenario you describe is a no crank no start which may be a security issue.

Totally get the frustration: it was always going to be a challenge. Perhaps park it for a while and come back to it?

 

Head in ME hands today... At this point I don't even KNOW if I'm looking forward to Saturday,,, XKR day, lol... OMG

 

By now I suspect you may have a bore wash problem unless the injectors are disabled.

 

I would like to hear and learn more about this... But I promise,,, I have not been turning the engine a lot with jumping the relay, or much at all if at all with the key OR turning the key and getting no result... It's like I know I won't get the desired result so I don't turn the key, much. Tired with it.

If it is cylinder wash,,, what do you suggest? Oil down a few cylinders?

I don't think I'm getting ignition/spark,,, fuel, or both...? the way I should.

Thing is, I know the "trigger" (meaning the signal or activate side of the relay from the ECU) lights up when I turn the key. My two last problems (known ) are tough ones. I say known because I know there will be more.

Bollocks!

 

JayJagJay,

The only thing I can say is....Keep at it. Don’t give up!

Far more knowledgable people than me on your problems. One thing to check is the inertia kill switch in the driver’s side dash fuse box.

 

Thanks Dave... Finally, I did. Seems right and reset. Lol,,, I was a little disappointed. It's just a matter of depressing the red but to reset, correct?

 

Hey 3Jay, yes that's right. Now inertia switches have gone defective [OMG - I was about to type "but you can always listen for the fuel pump" - you would have shot me! I'm Laughing at myself after your months of work trying to get the bloody pumps to work! That's probably the last thing you want to hear! Oops]

Better idea grab your multimeter & measure continuity.
John

 

Hahahaha... Cuz of the way I have it rigged UP,,, that pumps running full blast 24,7 even with the battery disconnected, lol. Sheeesh, this thing.

I'm doing, missing, not seeing something - that right in front of me... I'm going to go back over (yes, multi meter and maybe a members osilloscope, maybe) and give it another go. I can feel good about something... Shoot. The XJS work has been going beautifully! Rebuilding my injector wiring (don't laugh) now. Exhaust, suspension and some new sneakers, too. Beautiful...

I'm going to focus a little on voltage to relays. I hate when I have these epiphanies, kinda, but - for the issues I'm having at the moment, the no crank, and when jumping the relay and it does crank but not start - could it just be that the associated relays (ignition and fueling AND crank) just aren't getting what they need from a low battery??? Crazy maker. I mean, will a relay associated with those system actuate at LESS than 12+volts?

Then there's the PWM - whole other story...

I'll get it! In time! Just hope booooze doesn't get involved.