Shut Down while in Motion - Again

[txfromwi]

It's the 2013 V8, LR4, about 93K miles.
About a month ago it shut down several times in quick succession without warning, but re-started each time, each re-start required a quick bit of cranking, which I noted but did not report earlier.
We determined at that time that it was an old battery and I replaced it.
It has been fine since until this morning.

Today:
Shutdown while in motion, dashboard lit up like a Christmas tree.
Re-starts no issues, but needs a bit of cranking - not much.
Drove home no issues.
It's in the garage (whew!), but is failing intermittently.

If I give it a gentle rev up to maybe 1000 or 1500 rpm, it shuts down as the rpm returns to idle, sometimes.
It also shuts down while sitting at idle, sometimes.
When it shuts down it's a clean smooth action, RPM falls quickly to zero, no sputtering or trying to run.

No idiot lights and no codes on the IID.
(except the key fob has a low battery)

Clue - requires a bit of cranking for each re-start, less than a second, but it's definitely repeatable.
The cranking reminds me of when I did the crossover project and it took a bit of cranking to re-fill the fuel supply lines.
Crossover project was almost 5 years and about 3K miles ago.

Not to start down the wrong path...
I wonder if it's a fuel supply issue?


Thanks!
Dan

 

[Shaggy]

When it shuts down it's a clean smooth action, RPM falls quickly to zero, no sputtering or trying to run.

Dan, running out of fuel usually stumbles and sputters on the way out, so a clean instant shutdown makes me lean electrical, like power dropping to the ECM or the fuel pump driver for a split second. The extra cranking fits that too, since fuel pressure bleeds down the moment the pump cuts out. Since it'll do it in the garage, I'd hook up the IID, watch low side fuel pressure and battery voltage live, and wiggle the battery cables and main grounds while it idles. When you swapped the battery, did the old terminal clamps go back on?

 

[BBLR3]

Sounds like low pressure fuel sensor. Mine did this exact same thing when it went bad, just died randomly while driving. There's a few threads here about it.

 

[txfromwi]

Thanks for the hints.

I did check the battery connections when this first occurred - they were fine, but it was a quick shake.
However, this morning I did a firm shake and the negative connection was indeed loose.
So loose indeed that it easily comes right off the battery.
The nut was totally tight and the clamp is closed down absolutely as much as possible - but it still slips on the battery terminal and can come off easily.

I pried it apart and took a Dremel tool to it, but after one treatment there is no real change.

In your experience do I just buy a new cable assy, or do I keep going at it with the Dremel?

Thanks
Dan

 

[jlglr4]

They make battery post shims. Like a lead thimble with a split in it. Never used one, but seems like they’d work.

 

[txfromwi]

I was considering that as well.
Especially as the replacement cable is $266, out of stock pretty much everywhere except for FCP Euro, and might take a while to arrive.

Ordered a small piece of lead sheeting and will make a shim.

 

[ftillier]

The other thing you might get away with is compressing the clamp while it's closed, if you can get it into a vice and gently squeeze it on various sides. Probably wouldn't take much.

 

[davidrosenbloom]

Ok lets slow down a bit; you can use a walmart battery cable from the earth or neg terminal to the post on the frame; body; there s nothing special about the LR part; additionally if I were you I'd run #6 AWG copper stranded wire with soldered ends to the alternator casing (body) using one of the three bolts (the bottom backmost one is the easiest; AND I'd run the same #6 with same ends from under engine ground strap to position on top of frame grounding strap and then up again right to the battery terminal; fi you go online you want the solid brass or solid brass with gold p[lating which will have room for the main #2 wire and then two additional posrts (at least) for the two #6 wires; these straps are notorious for V drop b ut often only at certain amperage values; so you cant always catch them with a simple voltage drop test. In case you are intent on keeping those known failure prone earth terminals (neg) from JLR; simply take a piece of copper plate or brass shim and make the post bigger (Im not a fan since now we have a three point connection between the earth and the terminal) the other way is to take the terminal itself off and then grind out both mating surfaces about 1/16" on each side thus making the connection tighter; this works; but really your problem sounds a lot like a connector, bad ground, or even a number of other things including the dreaded wet parking sensor or CAN BUS. THe 5.0's and moisture just dont mix. I dont disagree with the idea above re: fuel sensor but you should be able to pick that up with a GAP tool; if its been outdoors for extended periods Id cehck for mice and wire chewing. You need live data when this occurs but first you need to solve the neg battery terminal issue; please reject the JLR option.
Dave R
07 L322
09 L322
12 L322