Car now starts but floods - where next?

I wrote a really long post out but scrapped it for this one which will be as to the point as I can be.

Following on from this thread: viewtopic.php?f=16&t=21561&start=0

I had a classic-sympathetic mechanic around today for a couple of hours and the news isn't great. He sorted the timing for me and the car now starts - however it floods itself after a short while and runs very badly. Someone's been at the carbs, they're set up differently (and badly).

So next step is to rebuild the carbs and renew the floats. Or could it just be a matter of adjusting or replacing floats?

Manifold is blowing - I can have that welded by a friend or replace it.

The fuel pump is one of these: ... B00HRLKATG and it's in the engine bay. I would look at replacing this with a more appropriate pump, with a regulator if necessary, at the rear of the car.

Carb rebuild - I have decent mechanical skills (I repair endoscopes for a living), so I would hope that I would be able to undertake this myself and then give them to the mechanic to install and set up. Am I being too optimistic?

My worry now is if I do all this, and it's still not right, I assume I'm then looking at a possible engine rebuild. I just don't have the space for this which is why I'm worried. I basically bought this car without having enough information which is my fault entirely, I was also too trusting. What I was told doesn't match up with what I now know which is the car at the moment is pretty broken and the previous owner apparently had a go at making good, and gave up. He was lucky enough that it ran well enough for a couple of test drives by myself and I took it off his hands like an idiot!

In all honesty I'm quite upset with myself and part of me wants to throw in the towel but the bigger part of me doesn't and wants to stay optimistic.

Any guidance would be of huge help. Mainly I am wondering (hoping) if the carbs, fuel pump, manifold are likely to be the end of my worries or not.




Well-Known Member
pardonthewait said:
My worry now is if I do all this, and it's still not right, I assume I'm then looking at a possible engine rebuild.
Why would you assume that? If it runs, albeit badly, and flooding, you should still be able to tell whether it's in need of a rebuild before you spend any more money on it.
Honestly because the car's just turning into a bit of a nightmare and this minute it's really getting to me.

Without wanting to sound like an idiot.. how?


Well-Known Member
pardonthewait said:
Without wanting to sound like an idiot.. how?
I don't think that makes you sound like an idiot, but if it's something that you think is beyond your knowledge, then as you had previously said:

pardonthewait said:
I had a classic-sympathetic mechanic around today
Then if you asked him he should be able to tell you whether the big ends are knocking, the mains are rumbling, or the rings are worn, whether it's running on all 8, even if it is running badly. In all the years of working on cars I can only remember once hearing an engine run and thinking it was OK only to find out later that it wasn't, and that was a 4 cyl engine with siamesed exhaust ports running without an exhaust manifold and exhaust system fitted, and the reason for that was it was so damn loud that I couldn't hear a thing, then, or for about a month afterwards, and there's no way yours should be as bad as that. If I had fitted a manifold and exhaust system I would have heard the problems, but there wasn't one available, so I took a chance and got caught out.
I wasn't available when the gent was round but he spoke to my dad - who will be around later this evening and I'll be grilling him.

All I can glean so far is that it was running very badly but the carbs were very poorly set up and set up differently to each other - and that he said carb rebuild/tune is obvious next step as well as sorting the manifold but he couldn't promise that that would make everything ok - which sounds reasonable to me.

With regards the fuel pump, I gather I have the option of replacing the one in the engine bay with a pull pump like a Huco, or fitting a push-type pump like a Facet in the rear. The Huco is lower pressure and shouldn't cause flooding (it says 'ere) and will be an easier job to fit - should pretty much drop in.

If I can't get the info I need from dad, I'll give the mechanic a call tomorrow.


Staff member
Yes to the fuel pump :)

A carb rebuild isnt that difficult. You can do them in about a day yourself if you're so minded.

The manifolds are cast iron so can crack. Best option is to look out for a second hand one. Try calling wins or mark gray in case they have any lying around....

I've ordered up a low pressure huco pump after searching on here to confirm which one, so will get that fitted as soon as I can. Even if it's what's overwhelming the carbs they'll still be well out of tune.

I guess it's a matter of finding out if it's just the floats, or a proper rebuild. There is a man about these parts who is well known for his carb expertise, so I will give him a ring tomorrow and find out what I might be looking at for an overhaul. Kind of of the opinion that the right way to do it may be to have them sorted and overhauled by an expert with the view of it being a long term thing. Pretty sure the car was laid up for quite some time so I feel it'll need more than just a quick tinker. Then I'll get them off and take a look. Who knows, they might be all sparkly and delightful inside... Yeah right! :roll: :LOL:

Shame about the manifold, won't be a matter of just having it welded then. I shall take a look around - in the meantime I should still be able to do the rest and get it running I hope.

Still, we're on the way. Progress! Feel a lot better than earlier.


Well-Known Member
Staff member
Floats that have taken on fuel and subsequently dropped sufficiently within the bowl will precipitate overflowing.

If the float/s have not taken on fuel, but the levels are excessive in terms of fuel volume within one or both bowls, again overflowing can occur.

It would be advantageous to rebuild both carbs completely, then set the jet heights at 2.5 turns down from the top of the bridge. This will enable the engine to start and run whilst they are balanced in terms of suction. You can then fine tune the jet height if necessary, but that initial setting is pretty close to the mark.


unstable load

Well-Known Member
I'd go about this one thing at a time if I were you....
1. check the carbs for holed floats and if found, rectify. ALSO, check for all-round condition while you are in there and clean it all nicely.
2. set float levels.
3.The manifolds do blow, sometimes. Check all the bolts are nipped up before you rip it all apart.
4.Does the system have the return line to the tank still connected and is it unblocked? I am not sure of the required pressure, but that pump could work.
5.Rebuild the carbs if needed, but it should be able to run well enough to determine if that is needed once you get the basics set-up vis-a-vis the basics.


Staff member
I think these are pretty normal teething troubles for a car that hasn't been used much.... Keep going and when it works you'll love it.
I'll stick the pump on then inspect the floats and the rest of the carbs, see where it takes me. If the carbs look Ok inside, I will just reset them to standard at first.

Thanks for advice all, I'll work my way down that list.
Good advice from everyone as usual.

Its easy to jump to terrible conclusions when something is not running right - I know because I have been there, my advice would be always to check the easy/cheap things first and when you are certain that the fundamentals are all correct but you still have a problem then its time to start getting more drastic with the troubleshooting.

Too often (on the internet in general) you see threads where people have changed literally every component all at once and still have a problem. Whilst having new stuff may sound like a great idea, often it just introduces new issues that confuse the original problem. For example pattern rotor arms and dizzy caps can be troublesome on the Rover V8.

SU's really are as simple as a carb gets - I rebuilt mine myself and it was straightforward enough to do. There are a few pdf's floating about on the interweb that cover overhauling them in detail, have a google and see what you can find.

Good luck! :D As Rockdemon says - when it works you will love it!
You're right, it is easy. The information was filtered through my mother who unfortunately does have a flair for the dramatic and a tendency to add her own spin to any information she passes on! Dad spoke to him also and was much more positive so we'll go with that!
I'm having similar issues with MVD307P, which had also been laid up for some time. Not wanting to hijack the thread at all, I'll throw my latest problem to you helpful guys.
Started her up on Sunday to take it back to my mums, ran sweet as a nut, very responsive with a lovely burble. Took it down the nearby bypass when it started popping and banging, total loss of power and then stopped. Coasted into a layby, left it a minute or two, got it started and headed for mums, packed up another 4-5 times in what was less than 2 miles, exactly the same symptoms. Carbs have been done, electronic ignition fitted, facet pump in engine bay (been there forever) with regulator fitted, am I right in thinking a lean mixture would make it run so bad? Or could it be a case of fuel vapourisation? I must admit I've been reading these posts with interest as my experiences with the car broadly match yours, when it runs well its the best car ever!
Just had a new shed delivered so hopefully from the weekend I'll be able to get her in the garage where I'll be more inclined to tinker, everyone's advice certainly gives me the confidence to have a go.

Machman - I once had very similar problems, caused by blocked tank venting.
It wasn't on a P6, in fact it was so long ago I can't remember which car it was and I don't know if the fuel system design on our Rovers would be prone to this, but it could be a possibility.
In my case, removing the well-sealed filler cap produced a rush of air into the tank and a muted 'bong' as the tank sprang back into shape, having been distorted by the low pressure! Running with the filler cap loosened as a test, got rid of the problem. Unblocking the tank vent pipe cured it permanently.
Huco pump fitted and working. Now need a real good tidy up of wiring and fuel pipes as I know the ignition system works.

To time the distributor correctly the mechanic removed the left hand (looking out from the cabin) stabiliser bar that attaches next to the distributor. I spoke to him tonight about this, and he reckons that it will be fine without it there as it's just a stabiliser for vibration etc.

In two minds about this.. I guess what he says makes sense but they presumably put it there for a reason!

Thoughts? Will it be ok without the stay bar?

Still won't start by the way but it's as cold as buggery out there and if it's still overfuelling I guess it wouldn't. My starter motor is now making a lovely squeal too :/ No idea if that was me the other day, or him, or it's just given up through so many attempts to start the car.



Well-Known Member
Staff member
pardonthewait wrote,...
To time the distributor correctly the mechanic removed the left hand (looking out from the cabin) stabiliser bar that attaches next to the distributor. I spoke to him tonight about this, and he reckons that it will be fine without it there as it's just a stabiliser for vibration etc.

In two minds about this.. I guess what he says makes sense but they presumably put it there for a reason!

Thoughts? Will it be ok without the stay bar?
The stabiliser bar is there for a very good reason, so I would find myself another mechanic.
It prevents the left hand engine mount from being subjected to constant tension whilst the engine is running, and even more when under acceleration.

Ultimately, the mount will fail, so I would advise refitting the bar before starting the engine.

As you surmised, the bar must be there for a reason, and Rover would never have added a such a piece without a sound engineering reason.



Staff member
The stay bar is to keep the engine from moving - i'd keep it on!

If it's flooded you'll need to let the fuel evaporate. take the plugs out and remove the elbows from the carbs...