Last request for help! Sorry for long post...

The dear old Series let me down big time last weekend on an event, so this
weekend I am trying to sort it out but with no success.

2.25 Petrol. Carburettor - BM Parts (Bearmach?) Zenith pattern, replaced
original carb about 6 months ago, has run fine up to now, idled at +/- 500
rpm like a sewing machine, although has always popped back a lot through the
exhaust on long downhills. Slight blow at manifold/exhaust joint after
fitting new exhaust. Carb has done about 2K miles, averaging 18-20 mpg.

Symptoms - engine hot with lots of slow driving & idling (temp gauge below
half as normal tho), suddenly refuses to idle and stalls. Only able to get
it running by increasing idle speed to silly amount, and even then it was
racing up and down and stalling without any intervention from me. I'm
suspecting a big air or internal fuel leak, so yesterday I -

* dismantled carb and did the "Zenith fix" - flatted the top/body mating
surfaces back to 100% flat and mirror finish (and boy did it need it - top
and body were badly warped and the surfaces apparently machined with a
chainsaw). Could get a 1mm feeler between top and straight edge at several
points before I started
* attempted to seal the redundant passage in the body as noted on several
"how-to" websites, only on this version of the carb there wasn't one
* set float height to 33mm as per book (this may need adjusting 1mm or so as
I have removed metal from the top and body, but it should be the basis for a
running engine I reckon)
* blew through all jets with airline
* checked fuel pump delivering - yes it was
* sealed air cleaner to carb flexible pipe with gaffer tape where it was
deteriorating
* cleaned and remade all joints on assembly with smear of orange Hermetite
(manifold/adaptor/carb) as well as correct gaskets
* broke and remade manifold/exhaust joint with Firegum - now no blowing at
all.

It now runs better (in that it will at least run unattended) but only with a
high idling speed, and the revs are still chasing up and down with a noisy
patter from the exhaust. If I try to reduce the idle to something normal,
it just waits a bit and then dies. It's still obviously VERY WRONG. Medium
and high speed running is (and always was) fine.

I have now totally run out of ideas. Can anyone suggest anything else
before I a) shell out 150 notes for a Weber, b) start looking for a diesel
transplant, or c) let the dog have a go on the basis that he can't do any
worse than I have?

All suggestions gratefully received. If you've read this far, thank you for
staying with me


--
Rich
==============================
Disco 300 Tdi auto
S2a 88" SW
Tiggrr (V8 trialler)

so Richard Brookman was, like...
> The dear old Series let me down big time last weekend on an event, so
> this weekend I am trying to sort it out but with no success.
>
> <snip sad story>

> All suggestions gratefully received. If you've read this far, thank
> you for staying with me

Forgot to say - also altering the idle air adjustment screw has no effect.
All the symptoms of an air leak, bit where?

--
Rich
==============================
Disco 300 Tdi auto
S2a 88" SW
Tiggrr (V8 trialler)

"Richard Brookman" <[email protected]> wrote in message
news:[email protected]...
> so Richard Brookman was, like...
>> The dear old Series let me down big time last weekend on an event, so
>> this weekend I am trying to sort it out but with no success.
>>
>> <snip sad story>
>
>> All suggestions gratefully received. If you've read this far, thank
>> you for staying with me
>
> Forgot to say - also altering the idle air adjustment screw has no effect.
> All the symptoms of an air leak, bit where?

Inlet manifold? Try squirting some wd40 around the inlet... though not too
much and beware of the risk of fire. The idea is that the WD40 will
momentairily plug any leak and it would run fine. Another trick is to stick
one end of a rubber hose in your ear hole and use the other stethascope
stylie to snif around the carb joints and inlet manifold joints for a leak.
To get the idea of what your listening for try it next to the intake. Any
leak will sound similar but lesser IYSWIM.

I had this on an Old sierra replacement engine. After 2 weeks of trying to
sort it I gave up and began to break the engine down into parts to sell. As
I removed the carb plate (after trying the head gasket twice on this
replacement engine) I saw a large tear in the inlet manifold where the guy
who I bought the engine from had clearly used the inlet as a point to hoist
the engine out of the donor. It was covered by an accelerator cable plate so
you couldn't see it.

I also had varying revs on a V8 at idel casused by a holed diaphram in the
advance retard unit. Try bolwing / sucking on this pipe to check if it's
holed.. If you go purple or suffocate then it's fine.

Other than that I'm stuffed for ideas too.

Lee D
--

www.lrproject.com

Workshop photos from Landrover repairs
& other such tinkerings.
Home of Percy the Jag powered Landrover

On or around Sun, 3 Jul 2005 13:48:25 +0100, "Richard Brookman"
<[email protected]> enlightened us thusly:

>The dear old Series let me down big time last weekend on an event, so this
>weekend I am trying to sort it out but with no success.
>

[snippage]

definitely sounds like an air leak. manifold-to-head joint,
manifold-to-carb joint... is the carb mounted on a plastic or other
insulating block?

as lee said, you can get air leaks in the dizzy unit.

Has it got a brake servo? if so, is the pipework and servo itself sound?

Check also that no plugs have unscrewed and disappeared from the manifold.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".

so Austin Shackles was, like...
>
> definitely sounds like an air leak. manifold-to-head joint,
> manifold-to-carb joint... is the carb mounted on a plastic or other
> insulating block?

Possibly manifold to head, although why that should suddenly start to leak I
can't think. Manifold to carb is belt-and-braces sound. Yes, the carb is
mounted on a plastic insulator, also in good condition.

>
> as lee said, you can get air leaks in the dizzy unit.

I've tried, honest, but I can't get my head far enough under the bonnet to
suck the pipe! However, I've run it with the vacuum advance disconnected
(very lumpy) and when you reconnect the pipe it perks up a couple of hundred
rpm, so the dizzy diaphragm would seem to be OK.
>
> Has it got a brake servo? if so, is the pipework and servo itself
> sound?

No servo.
>
> Check also that no plugs have unscrewed and disappeared from the
> manifold.

Visual check suggests everything OK - no cracks in manifold, and all plugs
present and correct. There is one empty screw hole in a raised boss just
behind the carb mounting, but there's no sign it's lost anything recently,
and blanking it with a finger makes no difference.

By process of elimination, it's got to be something with the manifold, or
else the almost-new carb is shot beyond redemption. I guess the manifold is
the next victim of my attentions.

Thanks for the help.



--
Rich
==============================
Disco 300 Tdi auto
S2a 88" SW
Tiggrr (V8 trialler)

so Lee_D was, like...
>
> Inlet manifold? Try squirting some wd40 around the inlet... though
> not too much and beware of the risk of fire. The idea is that the
> WD40 will momentairily plug any leak and it would run fine. Another
> trick is to stick one end of a rubber hose in your ear hole and use
> the other stethascope stylie to snif around the carb joints and inlet
> manifold joints for a leak. To get the idea of what your listening
> for try it next to the intake. Any leak will sound similar but lesser
> IYSWIM.

Good idea - I'll give that a go. I've tuned enough twin-carb setups on
bikes to know what I'm listening for.

> I had this on an Old sierra replacement engine. After 2 weeks of
> trying to sort it I gave up and began to break the engine down into
> parts to sell. As I removed the carb plate (after trying the head
> gasket twice on this replacement engine) I saw a large tear in the
> inlet manifold where the guy who I bought the engine from had clearly
> used the inlet as a point to hoist the engine out of the donor. It
> was covered by an accelerator cable plate so you couldn't see it.

This wouldn't account for a failure while running, though, or would it? I'm
more inclined to look for heat as the culprit (eg warping), hence the
lapping of the carb faces.

>
> I also had varying revs on a V8 at idel casused by a holed diaphram
> in the advance retard unit. Try bolwing / sucking on this pipe to
> check if it's holed.. If you go purple or suffocate then it's fine.

If I can work out a way to get my head between the carb and manifold I'll
give this a go.

> Other than that I'm stuffed for ideas too.

Glad it ain't just me then!
>
> Lee D

Cheers for this.

--
Rich
==============================
Disco 300 Tdi auto
S2a 88" SW
Tiggrr (V8 trialler)

On or around Sun, 3 Jul 2005 20:12:09 +0100, "Richard Brookman"
<[email protected]> enlightened us thusly:

>so Austin Shackles was, like...
>>
>> definitely sounds like an air leak. manifold-to-head joint,
>> manifold-to-carb joint... is the carb mounted on a plastic or other
>> insulating block?
>
>Possibly manifold to head, although why that should suddenly start to leak I
>can't think. Manifold to carb is belt-and-braces sound. Yes, the carb is
>mounted on a plastic insulator, also in good condition.
>
>>
>> as lee said, you can get air leaks in the dizzy unit.
>
>I've tried, honest, but I can't get my head far enough under the bonnet to
>suck the pipe! However, I've run it with the vacuum advance disconnected
>(very lumpy) and when you reconnect the pipe it perks up a couple of hundred
>rpm, so the dizzy diaphragm would seem to be OK.
>>
>> Has it got a brake servo? if so, is the pipework and servo itself
>> sound?
>
>No servo.
>>
>> Check also that no plugs have unscrewed and disappeared from the
>> manifold.
>
>Visual check suggests everything OK - no cracks in manifold, and all plugs
>present and correct. There is one empty screw hole in a raised boss just
>behind the carb mounting, but there's no sign it's lost anything recently,
>and blanking it with a finger makes no difference.
>
>By process of elimination, it's got to be something with the manifold, or
>else the almost-new carb is shot beyond redemption. I guess the manifold is
>the next victim of my attentions.

gasket can fail, and generally they do this relatively suddenly. consider
how an exhaust can be fine one minute and noisy the next...

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".

On Sun, 3 Jul 2005 15:05:27 +0100, "Lee_D"
<[email protected]> wrote:

>"Richard Brookman" <[email protected]> wrote in message
>news:[email protected]...
>> so Richard Brookman was, like...
>>> The dear old Series let me down big time last weekend on an event, so
>>> this weekend I am trying to sort it out but with no success.
>>>
>>> <snip sad story>
>>
>>> All suggestions gratefully received. If you've read this far, thank
>>> you for staying with me
>>
>> Forgot to say - also altering the idle air adjustment screw has no effect.
>> All the symptoms of an air leak, bit where?
>
>Inlet manifold? Try squirting some wd40 around the inlet... though not too
>much and beware of the risk of fire. The idea is that the WD40 will
>momentairily plug any leak and it would run fine. Another trick is to stick
>one end of a rubber hose in your ear hole and use the other stethascope
>stylie to snif around the carb joints and inlet manifold joints for a leak.
>To get the idea of what your listening for try it next to the intake. Any
>leak will sound similar but lesser IYSWIM.
>

Inlet manifold occurred to me too, as this was the cause of the
undiagnosable problem on the 101. But the symptoms seem wrong - it
runs well at higher revs / loads. The 101 would idle fine off load,
but as soon as you tried to rev it it would die - just ran too lean
and stalled.

Is compression even across the pots?

Are all the ignition bits in good fettle?


--

Tim Hobbs

'58 Series 2 88" aka "Stig"
'77 101FC Ambulance aka "Burrt"
'03 Volvo V70

so Tim Hobbs was, like...

> Inlet manifold occurred to me too, as this was the cause of the
> undiagnosable problem on the 101. But the symptoms seem wrong - it
> runs well at higher revs / loads. The 101 would idle fine off load,
> but as soon as you tried to rev it it would die - just ran too lean
> and stalled.
>
> Is compression even across the pots?
>
> Are all the ignition bits in good fettle?

Haven't done a compression test, no - would uneven cylinders give these
symptoms?

All ignition parts were renewed and set correctly a few months ago, and it
has run fine since then - until last weekend! I also checked/adjusted the
tappets as part of the exercise yesterday.

I took it for a decent run this afternoon and it drives like a nightmare!
Pulling up a steep hill is the only time it feels right. In top gear, with
no throttle (on a straight and empty road, natch) it was doing 30mph on one
occasion - ulp - and then 200 yards later, same trick, it would slow to
walking pace and then die.

I'm absolutely certain it's an air leak (what else can it be FGS?) but I've
done everything I know. I spose the next step is to take off the manifold
and start checking the solid bits.

Thanks for the post.

--
Rich
==============================
Disco 300 Tdi auto
S2a 88" SW
Tiggrr (V8 trialler)

On Sun, 3 Jul 2005 22:11:39 +0100, "Richard Brookman"
<[email protected]> wrote:

>I'm absolutely certain it's an air leak (what else can it be FGS?) but I've
>done everything I know. I spose the next step is to take off the manifold
>and start checking the solid bits.


Have you checked with a dwell meter? If it was an air leak it would be
ropy all the time and certainly not pull well under load. The dizzy
shaft wobbling about can cause your sort of problems. As can a closed
contact breaker gap.

AJH

so [email protected] was, like...
> On Sun, 3 Jul 2005 22:11:39 +0100, "Richard Brookman"
> <[email protected]> wrote:
>
>> I'm absolutely certain it's an air leak (what else can it be FGS?)
>> but I've done everything I know. I spose the next step is to take
>> off the manifold and start checking the solid bits.
>
>
> Have you checked with a dwell meter? If it was an air leak it would be
> ropy all the time and certainly not pull well under load. The dizzy
> shaft wobbling about can cause your sort of problems. As can a closed
> contact breaker gap.
>
> AJH

Another line of enquiry! Thanks for this. Too dark now, but I'll have a
look tomorrow. I know I should have checked these, but...

--
Rich
==============================
Disco 300 Tdi auto
S2a 88" SW
Tiggrr (V8 trialler)

>I took it for a decent run this afternoon and it drives like a nightmare!
>Pulling up a steep hill is the only time it feels right. In top gear, with
>no throttle (on a straight and empty road, natch) it was doing 30mph on one
>occasion - ulp - and then 200 yards later, same trick, it would slow to
>walking pace and then die.
>

That sounds very much like an inlet leak. Runs progressively leaner,
and your natural instinct is to press the pedal harder which makes the
problem worse.


--

Tim Hobbs

'58 Series 2 88" aka "Stig"
'77 101FC Ambulance aka "Burrt"
'03 Volvo V70

On Sun, 03 Jul 2005 22:24:38 +0100, [email protected] wrote:

>On Sun, 3 Jul 2005 22:11:39 +0100, "Richard Brookman"
><[email protected]> wrote:
>
>>I'm absolutely certain it's an air leak (what else can it be FGS?) but I've
>>done everything I know. I spose the next step is to take off the manifold
>>and start checking the solid bits.
>
>
>Have you checked with a dwell meter? If it was an air leak it would be
>ropy all the time and certainly not pull well under load. The dizzy
>shaft wobbling about can cause your sort of problems. As can a closed
>contact breaker gap.
>
>AJH

In theory yes, although the 101 would run really well for about 20-30
minutes, then it would slowly die away. Stop for 10 minutes and it
would cure itself. Then run fine for 5 minutes, then stop for 10
minutes. Then run for 2 minutes and so on, until give up and call
RAC. All the whlie it would idle absolutely fine and even.

In fixing the 101 we found a badly knackered dizzy and thought we'd
cracked it. Then a split diagphragm, thought we'd cracked it. Claggy
fuel filter sock - thought we'd cracked it. Every time, no better...

Richard - you'll have the best sorted broken down Landy in Britain
before you finish! Good luck.
--

Tim Hobbs

'58 Series 2 88" aka "Stig"
'77 101FC Ambulance aka "Burrt"
'03 Volvo V70

In message <[email protected]>
"Richard Brookman" <[email protected]> wrote:

> The dear old Series let me down big time last weekend on an event, so this
> weekend I am trying to sort it out but with no success.
>
> 2.25 Petrol. Carburettor - BM Parts (Bearmach?) Zenith pattern, replaced
> original carb about 6 months ago, has run fine up to now, idled at +/- 500
> rpm like a sewing machine, although has always popped back a lot through the
> exhaust on long downhills. Slight blow at manifold/exhaust joint after
> fitting new exhaust. Carb has done about 2K miles, averaging 18-20 mpg.
>
> Symptoms - engine hot with lots of slow driving & idling (temp gauge below
> half as normal tho), suddenly refuses to idle and stalls. Only able to get
> it running by increasing idle speed to silly amount, and even then it was
> racing up and down and stalling without any intervention from me. I'm
> suspecting a big air or internal fuel leak, so yesterday I -
>
> * dismantled carb and did the "Zenith fix" - flatted the top/body mating
> surfaces back to 100% flat and mirror finish (and boy did it need it - top
> and body were badly warped and the surfaces apparently machined with a
> chainsaw). Could get a 1mm feeler between top and straight edge at several
> points before I started
> * attempted to seal the redundant passage in the body as noted on several
> "how-to" websites, only on this version of the carb there wasn't one
> * set float height to 33mm as per book (this may need adjusting 1mm or so as
> I have removed metal from the top and body, but it should be the basis for a
> running engine I reckon)
> * blew through all jets with airline
> * checked fuel pump delivering - yes it was
> * sealed air cleaner to carb flexible pipe with gaffer tape where it was
> deteriorating
> * cleaned and remade all joints on assembly with smear of orange Hermetite
> (manifold/adaptor/carb) as well as correct gaskets
> * broke and remade manifold/exhaust joint with Firegum - now no blowing at
> all.
>
> It now runs better (in that it will at least run unattended) but only with a
> high idling speed, and the revs are still chasing up and down with a noisy
> patter from the exhaust. If I try to reduce the idle to something normal,
> it just waits a bit and then dies. It's still obviously VERY WRONG. Medium
> and high speed running is (and always was) fine.
>
> I have now totally run out of ideas. Can anyone suggest anything else
> before I a) shell out 150 notes for a Weber, b) start looking for a diesel
> transplant, or c) let the dog have a go on the basis that he can't do any
> worse than I have?
>
> All suggestions gratefully received. If you've read this far, thank you for
> staying with me
>
>

Have you tried running it with the air cleaner hose off? An internally
collpased hose can do this, as can a silted-up air cleaner (give it
a damed good clean-out, the silt in the bottom can do a very good
impression of looking like its meant to be there).

Richard
--
www.beamends-lrspares.co.uk [email protected]
Running a business in a Microsoft free environment - it can be done
Powered by Risc-OS - you won't get a virus from us!!
Helping keep Land Rovers on and off the road to annoy the Lib Dems

On or around Sun, 03 Jul 2005 22:24:38 +0100, [email protected]
enlightened us thusly:

>On Sun, 3 Jul 2005 22:11:39 +0100, "Richard Brookman"
><[email protected]> wrote:
>
>>I'm absolutely certain it's an air leak (what else can it be FGS?) but I've
>>done everything I know. I spose the next step is to take off the manifold
>>and start checking the solid bits.
>
>
>Have you checked with a dwell meter? If it was an air leak it would be
>ropy all the time and certainly not pull well under load. The dizzy
>shaft wobbling about can cause your sort of problems. As can a closed
>contact breaker gap.

I've had engines with air leaks that run OK at higher throttle openings,
mind. depends on the carb and how much fuel it delivers, also, the inlet
leak is worse under over-run or idle conditions when the inlet depression is
greater. Put a vacuum gauge on it; that's what identified the fault on
mine.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".

so Tim Hobbs was, like...
>> I took it for a decent run this afternoon and it drives like a
>> nightmare! Pulling up a steep hill is the only time it feels right.
>> In top gear, with no throttle (on a straight and empty road, natch)
>> it was doing 30mph on one occasion - ulp - and then 200 yards later,
>> same trick, it would slow to walking pace and then die.
>>
>
> That sounds very much like an inlet leak. Runs progressively leaner,
> and your natural instinct is to press the pedal harder which makes the
> problem worse.

No, pressing the throttle makes it run as normal - from about 1/3 throttle
upwards it's fine. It's the idle (and the driving around at or near zero
throttle - which is quite a lot in town and on slowish roads) that's the
problem.

--
Rich
==============================
Disco 300 Tdi auto
S2a 88" SW
Tiggrr (V8 trialler)

so Tim Hobbs was, like...
> On Sun, 03 Jul 2005 22:24:38 +0100, [email protected] wrote:
>
>> On Sun, 3 Jul 2005 22:11:39 +0100, "Richard Brookman"
>> <[email protected]> wrote:
>>
>>> I'm absolutely certain it's an air leak (what else can it be FGS?)
>>> but I've done everything I know. I spose the next step is to take
>>> off the manifold and start checking the solid bits.
>>
>>
>> Have you checked with a dwell meter? If it was an air leak it would
>> be ropy all the time and certainly not pull well under load. The
>> dizzy shaft wobbling about can cause your sort of problems. As can a
>> closed contact breaker gap.
>>
>> AJH
>
> In theory yes, although the 101 would run really well for about 20-30
> minutes, then it would slowly die away. Stop for 10 minutes and it
> would cure itself. Then run fine for 5 minutes, then stop for 10
> minutes. Then run for 2 minutes and so on, until give up and call
> RAC. All the whlie it would idle absolutely fine and even.

Ah - that's the very thing mine *won't* do.

>
> In fixing the 101 we found a badly knackered dizzy and thought we'd
> cracked it. Then a split diagphragm, thought we'd cracked it. Claggy
> fuel filter sock - thought we'd cracked it. Every time, no better...
>
> Richard - you'll have the best sorted broken down Landy in Britain
> before you finish! Good luck.

Thanks, Tim - we aim high here.



--
Rich
==============================
Disco 300 Tdi auto
S2a 88" SW
Tiggrr (V8 trialler)

so beamendsltd was, like...
> >> All suggestions gratefully received. If you've read this far, thank
>> you for staying with me
>>
>>
>
> Have you tried running it with the air cleaner hose off?

Yes

> An internally
> collpased hose can do this, as can a silted-up air cleaner (give it
> a damed good clean-out, the silt in the bottom can do a very good
> impression of looking like its meant to be there).

When the problem first arose, taking the air cleaner hose off the carb
killed it stone dead. After my attentions at the weekend it will run with
it on or off - no difference. The hose was full of holes anyway (hence my
email to you), but I gaffered it up to be on the safe side.

--
Rich
==============================
Disco 300 Tdi auto
S2a 88" SW
Tiggrr (V8 trialler)

On or around Mon, 4 Jul 2005 19:09:44 +0100, "Richard Brookman"
<[email protected]> enlightened us thusly:

>so Tim Hobbs was, like...
>>> I took it for a decent run this afternoon and it drives like a
>>> nightmare! Pulling up a steep hill is the only time it feels right.
>>> In top gear, with no throttle (on a straight and empty road, natch)
>>> it was doing 30mph on one occasion - ulp - and then 200 yards later,
>>> same trick, it would slow to walking pace and then die.
>>>
>>
>> That sounds very much like an inlet leak. Runs progressively leaner,
>> and your natural instinct is to press the pedal harder which makes the
>> problem worse.
>
>No, pressing the throttle makes it run as normal - from about 1/3 throttle
>upwards it's fine. It's the idle (and the driving around at or near zero
>throttle - which is quite a lot in town and on slowish roads) that's the
>problem.

opening the throttle makes less inlet manifold vacuum, thereby sucking
proportionally less air through the leak, and at the same time delivers more
fuel.

On the engine I had with inlet manifold problems (1500 ford), it had an
aftermarket manifold which had thinner flanges than the standard exhaust
manifold. This manifold, though, allowed of mounting the twin-choke carb
from the GT version. However, the manifold had half-holes and shared half
it's mounting bolts with the half-holes on the exhaust manifold. Which was
fine if using the original manifold. addition of some spacers once I'd
eventually worked out what was wrong made it seal fine and solved the
problems.


--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".

Hi Richard,

Had a similar problem before, after a lot of trial and error I replaced the
condenser - sorted mine out, funny thing was it had only been replaced three
weeks before!

Cheers

Mac