75 P6 V8 - Bye, this car

[forddeliveryboy]

Can you make this happen by revving the engine with no load, ie when stationary? 

 

I'd be trying a gravity fuel feed (jerry can above the level of the carbs) to see if anything changes. If that's not easily done, how much is involved to reconnect the mechanical fuel pump? Or has this been left inline, aided by the electric one?

[Conrad D. Conelrad]

Nah, that's part of the problem - stationary, it'll rev to redline without a hiccup. The problem only occurs under load. Makes it hard to troubleshoot.

 

Mechanical pump permanently blanked off, fuel lines to it removed and pump itself flogged on eBay!

 

There'll be no advance on this until I can swap the electric pump for a spare, tomorrow, I hope.

[forddeliveryboy]

Good job the weather's so fair. Eek!

[mat_the_cat]

I know that you have ruled out most of the ignition system, but the rev counter dipping suddenly is classic of an ignition fault and doesn't fit in with a fuelling problem. The distributor sensor might be a possible still - I can't see that you've tested it? - or HT insulation breaking down under load?

 

What you can do to prove beyond all doubt whether an ignition fault or not, is connect up a strobe timing light with a pickup on one of the HT leads. This will flicker as normal when sparking is taking place, but will momentarily pause if a misfire occurs under load. That's saved me a couple of times!

 

(I'd been so certain it was an ignition problem I hadn't even bothered mentioning this check before! Now there is some doubt, although I really can't see *how* a fuel problem could cause the exact symptoms).

[Conrad D. Conelrad]

I changed the fuel pump. 

 

Another hour of misery under the car. At least this job didn't spiral out of control. It nearly did - the bullet connectors on the pump tore off instead of coming undone, and the new pump's wires were significantly shorter than the old one's, so I had to solder on extensions. I marvelled at the inaccessible bolts holding the pump in place, because I was the one who installed it. My arms must have been different shapes a few months ago. Maybe I should stop bathing them in petrol.

 

I tried blowing through both pumps to gauge the difference. They were different - the new pump can be blown through easily, while the old one does offer a bit of resistance. Feeling positive at this point! 

 

One of the fittings on the new pump was rounded off. I decided it was best to leave it alone, even though as I bolted the pump into place I thought to myself "I bet this leaks profusely". Once everything was installed, I flicked the ignition on to make sure everything was sound. After I got the pump to stop leaking profusely, it was time to stick the wheel back on and hit the road.

 

How did it drive? Perfectly. Lots of go. Felt like its old self. Everything was great. I meandered about locally, with lots of acceleration where the opportunely arose. No issues. Once I was confident enough, I braved the motorway. It got onto the motorway just fine, but when I went to overtake someone, I felt it lose power again. Fudge. 

 

Some observations - the car is almost back to normal, it just still doesn't like the motorway. Previously when it lost power on the motorway, there was no way to recover. This time, I backed off and it was okay. I came off at the next exit and the car was fine again. 

 

I don't see how it can be ignition when changing the pump made such a huge difference. It's got to be something tiny, something which I'm now sure involves the fuel tank outlets somehow. 

[LC Torana]

Even now, after reading all that, I would still like to know what the timing and dwell readings are.

[forddeliveryboy]

Is there a restriction in the pump, possibly a filter mesh in the inlet side which is easily and mildly silting up, but sufficiently enough to hamper full flow? And which isn't allowing as much fuel as the V8 needs under full load? Although the volume the youtube vid you posted suugested it could supply to 4mpg - I wonder if full throttle is more than that?

 

Try a gravity feed with no restrictions, if poss. IBC on the roof with a drainpipe to the carbs.

[matty879]

ive not read all this thread,but have the needle valves and floats been checked,possible the float bowls aint filling up enough to sustain full throttle,ive had a car that was ace driven normally,same symptoms as yours when i gave it some welly.

[Asimo]

Do we now know where the Rover poltergeist of random doom has relocated to, following the destruction of her last home?

[alf892]

  On 08/11/2016 at 00:40, forddeliveryboy said:

Is there a restriction in the pump, possibly a filter mesh in the inlet side which is easily and mildly silting up, but sufficiently enough to hamper full flow? And which isn't allowing as much fuel as the V8 needs under full load? Although the volume the youtube vid you posted suugested it could supply to 4mpg - I wonder if full throttle is more than that?

 

Try a gravity feed with no restrictions, if poss. IBC on the roof with a drainpipe to the carbs.

This..........or given that the new pump had it going OK for awhile maybe there is a build up of crud at a pipe joint?

[Junkman]

  On 08/11/2016 at 06:47, Asimo said:

Do we now know where the Rover poltergeist of random doom has relocated to, following the destruction of her last home?

 

No!

[mat_the_cat]

  On 07/11/2016 at 23:15, Conrad D. Conelrad said:

I don't see how it can be ignition when changing the pump made such a huge difference.

 

I stand corrected then! Although I still don't see how the symptoms fitted the cause. The only thing I can think of which could explain is something marginal in the ignition system, the effect of which is magnified with a weak mixture caused by a failing fuel pump. That seems rather unlikely though, so like you would be thinking along the lines of insufficient fuelling under load.

 

Is there a return line to the tank? Does this have a restrictor fitted?

[Junkman]

Well, there is a return pipe to the tank and the restrictor is - well - the standard one. I was also thinking fuel pressure lately, since there certainly is no issue with fuel quantity.

However, the system is currently severely bodged. The fuel pump is in the back and it is connected to the reserve outlet, because the reserve tab in the engine compartment is disabled.

If it was my car, I'd reconnect all fuel lines the way God and Spen King did in the first place and put a proper suction pump like a Hüco aft of the reserve tab in the engine compartment.

I ran this setup successfully in the haunted car for Months, until it burned away a section of a piston...

I guess the ideal setup would be a Hüco style pump aft the reserve cock, but with a check valve between it and the carbs. Which I never fitted, despite it worked well on my car without.

But I always wanted to, honestly.

 

My car currently has the bog standard fuel supply system, mechanical fuel pump and all. It does tend to vapourise as usual, but only after I brimmed it with Shell V-Power.

As long as I used Tesco 99, it didn't happen as far as I can remember. So I will refill with that stuff and see what happens. If it vapurises with that as well, I'll fit a Hüco in addition to the

original pump and wire it in with the Kenlowe, i.e., only when the Kenlowe kicks in, the Hüco acts as a booster. Fan and thus fuel pump can be overriden with a dahboard mounted switch

on demand.

 

However, this is only partially relevant for Conelrad's car and many other P6 V8s, since his is a later reduced compression example running on 95.

Mine is an early high compression type, so I have to do some tedious petrol alchemy all the time anyway.

In France, they all run their P6 V8s on e85 with electric pumps and Land Rover spec SU needles. They just laugh at us.

[Conrad D. Conelrad]

  On 09/11/2016 at 02:17, Junkman said:

However, the system is currently severely bodged.

 

creatively re-imagined

[Junkman]

Severely bodged. It bears little to no resemblence to what Spen King devised.

[Conrad D. Conelrad]

  On 09/11/2016 at 02:49, Junkman said:

Severely bodged. It bears little to no resemblence to what Spen King devised.

 

 

PATENT No. 267419 - A DEVICE FOR BOILING PETROLEUM

[Ghosty]

  On 08/11/2016 at 10:43, Junkman said:

Yes, and I'm not saying anything.

 FTFY

[Conrad D. Conelrad]

Alright, back under the car. Today's plan: return the fuel lines to near standard and install a completely different fuel pump in the engine bay. 

 

Last time I was surprised by how much fuel came out of the tank, so I drove until the needle was on the 'empty' stop, and then drove some more. I'd also learned that it is better to let the tank drain itself slowly, rather than removing the inlet so it all comes out at once. I'm now so practiced at this miserable job, I didn't spill a drop.

 

 

Replacing Unbranded Chinese Fuel Pump #2 is this nice Huco pump, on loan from the Junkman collection. Unlike the cube clones, it's designed to pull fuel from the engine bay, so it can be mounted in a more convenient place and also retain the Rover's original fuel reserve setup. It's got a wonderful high quality feel to it, and really nifty re-positionable inlet/outlet pipes. 

 

 

Look at it go!

 

 

But has it fixed the problem? 

 

Unreservedly, yes. The car immediately felt better. On Tuesday I'd abandoned it in a sidestreet because it was faltering, today I took it on the motorway and blazed up and down the slip roads with not so much as a hiccup. It's as happy on reserve as main petrol supply.

 

So, it looks like the fuel pump had started to die. The spare fuel pump I fitted was also dying, in the same way, but not quite as much. 

 

[LC Torana]

Now you have full fuel pressure you'll soon find out whether your carb needles & seats are worn.

 

Keep checking the dipstick for a while.

[billyboy406v6]

  On 24/11/2016 at 22:42, LC Torana said:

Now you have full fuel pressure you'll soon find out whether your carb needles & seats are worn.

 

Keep checking the dipstick for a while.[/quo

 

 

Sent from my iPhone using Tapatalk

[billyboy406v6]

Excellent result, would have bridged it ages ago !

 

 

Sent from my iPhone using Tapatalk

[Conrad D. Conelrad]

A fun coincidence this week:

 

 

It's been all fun actually. It's been driving so well. It's got a new fuel pump all of its own (the fifth fuel pump fitted to this car in two years!) which is silent to the point of being unsettling when I turn the ignition on. I can drain my tank down to the last drop thanks to the re-instatement of my reserve tap. 

 

I still wouldn't mind figuring out exactly what went wrong though - one theory is that my subtle alteration of the fuel return line removed fuel pressure at the carbs when they were at their most demanding, but I'm not sure. 

 

 

 

Also this week the radio stopped working, and the heater, while still working, has lost its 'hot'. 

[Junkman]

The problem is very obvious.

The "defunct reserve fuel line", aka original main fuel line, does not have the restrictor for the return line, that the original reserve fuel line has.

Thus no fuel pressure was created.

 

We remember: The fuel pressure is created by a restrictor where the return line meets the reserve fuel line.

[Conrad D. Conelrad]

The defunct reserve fuel line is the original fuel reserve line. The fuel return line is also unchanged. The excess fuel was still being pumped down the same return line, through the same restrictor. 

 

I did not change the fuel lines at all. I only swapped them at the tank end. 

 

 

The car was always drawing fuel through the original main fuel line. 

[Junkman]

Yes, you connected the return line to the main line, instead of the reserve line, where it belongs.

 

In the original configuration, as long as the car gets fuel from the main line, the return is fed into the reserve line.

The weight of the petrol before reserve is met adds to the build up of fuel pressure in addition to the restrictor.

Once it is switched to reserve, it gets petrol from the reserve line, and the return line.

 

After you swapped them around, the return started to terminate 4 inches from the bottom in the tank.

The weight of the petrol was thus less, thus reducing the fuel pressure and once the petrol level became low,

the return didn't feed back into the line you were drawing petrol from, because liquids always go the way of the

least resistance, which in your case was up into the tank.

 

I bet your configuration would have worked perfectly well with a fully brimmed tank until about the half full mark.

[Conrad D. Conelrad]

Yes, I know - that's what I said I worried would happen when I did it. We're talking about the same thing but using the same terms differently. 

[Conrad D. Conelrad]

Wow, I'd forgotten about all that fuelling rubbish. Glad that's behind me. No problems to report since. 

 

Oh, except all my brake fluid went missing. 

 

 

I hadn't noticed anything untoward with the brakes, but sudden fluid loss should probably be investigated. I refilled the reservoir, parked the car on a large sheet of card and pumped the pedal for a while. Then I combed the system for leaks, even used my cool new boroscope to peek at the inaccessible bits of pipes and calipers. But not a sign of fluid loss anywhere. Not a speck on the cardboard. 

 

Then the strange thing - with me checking the fluid daily, the level didn't fall a single millimetre for a fortnight. Then suddenly:

 

RECONSTRUCTION

 

Okay, shit. Where's it going? At this point I'd have been over the moon to find a cracked pipe or damaged flexi, because fluid vanishing with no trace means either the servo is filling up or the rear calipers are filling up. Neither is good. Let's poke a dipstick into the servo first, since it's the more accessible of the two. 

 

 

 

 

There is some evidence of brake fluid in the servo. More brake servo problems, wow, who'd have thought? I'm happy it's not the rear calipers, although the brake servo kept this car off the road for months in 2014, so... maybe I'm not happy at all?

 

OTHER THINGS WHICH HAPPENED

 

It suddenly got loud at a set of traffic lights. I couldn't remember seeing this hole before, so it was a key suspect.

 

 

Sometimes you just have to accept a component has had its day. This long suffering back box has already been patched twice, and a lot of the stuffing has fallen out this time. When new ones are available off the shelf, you'd have to be a real cheap piece of shit to bodge this rotten one back together with welded on bits of tin and exhaust putty. 

 

 

But it came out okay, so... maybe I am happy?

 

ALSO

 

It's not all being a cheapskate here! I also changed the oil for some new high quality stuff with a bottle of ZDDP additive. Amazingly, this has made the tappet noise almost vanish (still a little when it's very cold) and, even more amazingly, taken my oil pressure higher than it's ever been. 

 

 

That's astounding oil pressure for warm idle! ASTOUNDING. Best of all, there can't be any downside to improved oil pressure, can there?

 

What's that smell?

 

 

Oh, ffs. I'm not happy at all. 

 

[320touring]

I think you should take a similar approach to e30 owners with the old m20 engine..

 

If its leaking, no need to worry as there's still fluid in it.

 

Worry when it runs out;)

 

Oil leak looks a pita, as does brake servo- I can hear Junkman's harrumphs from here

[Jim Bell]

Do not like.

[Conrad D. Conelrad]

Servo rebuild kit ordered. I can fit the new seals myself, no hassle - but I can't bleed the brakes afterwards. That's the sticking point.