New Ls400 Owner....with A Problem!

KevSeymour · September 14, 2014

Hi All,

About 3 weeks ago i bought home a 1992 LS400, 165k on the clock and still looking good!

However.... it's just started intermittently cutting out. From cold it'll run fine, but eventually (this could be ten miles or 100 miles later) it'll start to struggle to rev, then eventually the engine will die. It mostly start doing it when i'm slowing down for something, but again this could just be lifting off or canceling the cruise @ 70mph to allow for traffic, or it could be slowing to a stop at a junction in town.

I think it's temperature related, and is definitely electrical. Water temp stays constant and there's plenty of coolant in it.

Today, it got worse, i went to Silverstone which is about 45 miles from me, up the M1 then across country - not a problem.

Then coming home at 1pm i barely got out of the gate before it started to play up again, just before the slip road to the A43. We did get it going again, i think being able to run at a constant speed in clear air keeps it happy. But it threw a properly tantrum after about 20 miles.

I eventually got home an hour ago, 7.30. Via 2 AA patrol call outs then eventually a flat bed to bring me the last stretch.

The car cooled down waiting for the 1st AA patrol, so he followed me for about 10 miles just to check it would be alright. By then the ambient temperature had dropped so i was half confident of getting home. WRONG! 2 1/2hrs in a bus stop in Dunstable later and we got lifted.

Now what do i do?

It needs plugging in for a diagnostics check, i know (i wish the AA patrols could have had the right kit to do that!), but does this sound like a common problem?

First AA patrol chap reckoned on the crank sensor?

Thanks in advance, beers to anyone who can help me sort it out without spending £££. Virtual beers if you're not local, real ones if you are!

Cheers,

Kev

The-Acre · September 14, 2014

Hi Kev, welcome to the LOC. Sorry to hear your tale of woe, especially as you drive one of the most reliable cars in the world! I'm guessing that most replies will suggest you have a diagnostic check first. It sounds like fuel starvation but that wouldn't explain why it's OK sometimes. What sort of service history has it got?

KevSeymour · September 16, 2014

Hi Phil, and thanks for the welcome.

I got enough sevice history with the car to be happy that the car's been maintained well enough over the last 5 years, but not a lot of detail prior to that. Is there anything specific i should be looking for? I'm pretty confident this wasn't a problem the previous owners would have known about, we went on quite a lengthy test drive, it's just one of those things.

I've just found an online tutorial to read the fault codes myself so i'll be doing that in the next few days.

Cheers,

Kev

The-Acre · September 17, 2014

I think the fault code route is the first thing you need to do. The fuel filters can, I believe, be an issue if they're not changed. Being under the car at the rear makes them easy to overlook.