The V8 Owners Forum -

Good morning everyone

Just found this forum, what a great resource! I've recently bought 'Big Red', a 1968 Land Rover Series 2a long wheelbase, with a Rover V8 in it. No doubt lots of work ahead, but it's basically my dream vehicle, in great shape for a 50 year old workhorse, and maybe the most beautiful sound ever!

Got a bit of a problem with loss of power at high (50ish) speeds - sputters and loses all power - til you pull over to a stop and then fine again, but otherwise dead happy with it so far!

I would guess

Not enough fuel being delivered by the pump to feed the carburettors, and when you slow down it all catches up and works as it should.

Check fuel filters and pipes to see the fuel flows through with no restrictions

Ian

Thanks Ian - good suggestion I'll have a look. I should probably explain it a bit better as well, that was hardly descriptive! Might see if I can get a video of it happening! Only intermittent, it's not a guaranteed 'get to 50ish and this will happen' - we did a 250 mile trip collecting it and it did that about 8-10 times throughout, always seemed to be the same circumstances though rather than totally random. I wondered whether it might be sucking up crud from the tank then dropping it back in when the fuel flow drops but good idea about the filters and pump...

N

Odd thing is that letting off the gas or putting the clutch in seems to fix it, but as soon as you put the load back on it sputters again. Never actually dies, but sounds like chitty-chitty-bang-bang without the backfiring. And once it's started doing it, slowing down a bit, or even a lot, doesn't help.

Only coming to basically a dead stop (or near as dammit) fixes it, but it does so immediately. Soon as you've done that, can get right back on the road and it's like it never happened.

No smoke of any kind at any stage.

Take the top of the carbs off - just 4 small screws on each carb and check the rubber diaphragm inside - if perforated this can cause symptoms like you describe. Cheap and easy to replace and you should carry some in your spares.

Garry

Thanks Gary - haven't tried taking them apart just yet (been working away) but the diagrams I can find of SU carbs don't seem to show a rubber diaphragm there (although Strombergs do) ... I'm going to go out and have a better look tomorrow though so will hope it's that easy a fix!

Oh ok - don't know about SUs - just assumed the engine was fitted with the usual Zenith CD175s.

garry

Just checked and they're SU HIF6's (part no AUD521 L and R) which is good in that it's what it should have as a P6 engine so I haven't been fibbed to at least! Haven't had the chance to test the fuel pump properly, but I notice that the inline fuel filter that's installed looks pretty filthy from the outside, and it's been installed after the pump, rather than before it, which is what I understood you were supposed to do - could be the pump's full of crap then.

Can't make out any identifying marks on the pump itself either but it's pretty high up on the wing which probably won't be helping matters generally either. Bit more exploring tomorrow...

It it an SU pump? The P6 cars had an AC mechanical one with fuel return line.
SU pumps can wear and not pump as much a when new. But are also easy to overhaul. You could also check is actually big enough for the job.
You can check the flow by feeding the pump into a litre bottle etc and timing how long it takes to fill.

It's not a mechanical anyway, but can't see any ID marks on it anywhere. I pulled the pipe off the carb and the flow seems pretty piddly to me - but then I'm not sure what it should look like yet. I've asked my local garage to have a look as I've been a bit snowed under at work, interesting to see what they reckon.