Re: Engine Problem with 3.5EFI Rangie

Hi

I have a similar problem - 1987 RRC Vogue 3.5EFI

Driven 'around town' and on light throttle openings = excellent driving.
Fuel consumption = 17.5mph (round-town) - which I thought was generally OK.
BUT - on the open road perhaps with a gentle up-incline - push on the
accelerator
and power falls off - engine 'popping' 'mis-firing'
power drops until it is necessary to change down!!!!
Then get to back to 'light' throttle openings.
Done all the obvious things including spark plugs of 1 higher in heat range.
My analysis so far is that on light throttle the vacuum advance is keeping
the spark when/where it wants to be.
OR some problem with the air-flap thing which causes excess fuel injection.
Any hints/clues would be appreciated as I don't believe it taking things
apart on a 'just-in-case' basis.

David
Christchurch, New Zealand.

"Paul S. Brown" <[email protected]> wrote in message
news:[email protected]...
> A friend of my wifes has asked me to take a look at their 1986 RRC which
has
> a problem which is that intermittantly it loses power and dumps large
> amounts of black smoke out the back end of the car and occasionally stalls
> at idle.
>
>
> P.

On Sat, 7 Aug 2004 11:19:06 +1200, "David Grant" <[email protected]>
wrote:

>Hi
>
>I have a similar problem - 1987 RRC Vogue 3.5EFI
>
>Driven 'around town' and on light throttle openings = excellent driving.
>Fuel consumption = 17.5mph (round-town) - which I thought was generally OK.
>BUT - on the open road perhaps with a gentle up-incline - push on the
>accelerator
>and power falls off - engine 'popping' 'mis-firing'
>power drops until it is necessary to change down!!!!
>Then get to back to 'light' throttle openings.
>Done all the obvious things including spark plugs of 1 higher in heat range.
>My analysis so far is that on light throttle the vacuum advance is keeping
>the spark when/where it wants to be.
>OR some problem with the air-flap thing which causes excess fuel injection.
>Any hints/clues would be appreciated as I don't believe it taking things
>apart on a 'just-in-case' basis.
>
>David
>Christchurch, New Zealand.
>

It also sounds similar to the problem I had with the 101, which turned
out to be an inlet manifold leak. What is it like when cold - does
the problem get worse as the engine warms up?

Could also be fuel starvation - if you are getting a backfire that
would suggest it is running too lean at higher throttle. Possible
causes there would be dicky fuel pump, blocked line, blocked filter
etc etc.
--

Tim Hobbs

'58 Series 2 88" aka "Stig"
'77 101FC Ambulance aka "Burrt"
'95 Discovery V8i aka "The Disco" (FOR SALE)
'03 Volvo V70

My Landies? http://www.seriesii.co.uk
Barcoding? http://www.bartec-systems.com
Tony Luckwill web archive at http://www.luckwill.com

Tim Hobbs wrote:
> On Sat, 7 Aug 2004 11:19:06 +1200, "David Grant" <[email protected]>
> wrote:
>
>
>>Hi
>>
>>I have a similar problem - 1987 RRC Vogue 3.5EFI
>>
>>Driven 'around town' and on light throttle openings = excellent driving.
>>Fuel consumption = 17.5mph (round-town) - which I thought was generally OK.
>>BUT - on the open road perhaps with a gentle up-incline - push on the
>>accelerator
>>and power falls off - engine 'popping' 'mis-firing'
>>power drops until it is necessary to change down!!!!
>>Then get to back to 'light' throttle openings.
>>Done all the obvious things including spark plugs of 1 higher in heat range.
>>My analysis so far is that on light throttle the vacuum advance is keeping
>>the spark when/where it wants to be.
>>OR some problem with the air-flap thing which causes excess fuel injection.
>>Any hints/clues would be appreciated as I don't believe it taking things
>>apart on a 'just-in-case' basis.
>>
>>David
>>Christchurch, New Zealand.
>>
>
>
> It also sounds similar to the problem I had with the 101, which turned
> out to be an inlet manifold leak. What is it like when cold - does
> the problem get worse as the engine warms up?
>
> Could also be fuel starvation - if you are getting a backfire that
> would suggest it is running too lean at higher throttle. Possible
> causes there would be dicky fuel pump, blocked line, blocked filter
> etc etc.

Agreed. Could also be (lean wise) faulty PCV valve or leaky diaphragm
in the brake booster. If you want help/opinion a bit closer to home
(Auckland, and get to Chch from time to time) email me (unmunge as per
sig) or phone me on (027) 473-2631 during sociable daylight hours.


--
EMB
change two to number to reply

In <[email protected]> David Grant wrote:
> Hi
>
> I have a similar problem - 1987 RRC Vogue 3.5EFI
>
> Driven 'around town' and on light throttle openings = excellent
> driving. Fuel consumption = 17.5mph (round-town) - which I thought was
> generally OK. BUT - on the open road perhaps with a gentle up-incline -
> push on the accelerator and power falls off - engine 'popping' 'mis-
> firing' power drops until it is necessary to change down!!!! Then get
> to back to 'light' throttle openings. Done all the obvious things
> including spark plugs of 1 higher in heat range. My analysis so far is
> that on light throttle the vacuum advance is keeping the spark when/
> where it wants to be. OR some problem with the air-flap thing which
> causes excess fuel injection. Any hints/clues would be appreciated as
> I don't believe it taking things apart on a 'just-in-case' basis.
>
> David
> Christchurch, New Zealand.

My first candidate would be the fuel pump/system. This sounds like
classic fuel starvation problems. When was the fuel filter last changed ?
If you don't have a suitable pressure gauge to measure the fuel rail
pressure this can be difficult to diagnose without changing the pump.
You could divert the fuel return pipe and see if fuel is still being
returned when the engine starts missing. If the fuel return dries up
then the pump isn't delivering enough pressure/fuel.

Other than chacking for leaks, check the throttle position sensor (
throttle pot) and the air flow meter output. These are easy to check
with a multimeter. If you haven't got a manual that tells you how too
carry out the checks let me know and I'll p0ost a description.

On the ignition side, is it throttle position or rpm dependant ? If it's
rpm dependant then maybe the mechanical advance weights are seized.

cheers

Dave W.
http://www.yorkshireoffroadclub.net/

Tim Hobbs wrote:
> On Sat, 7 Aug 2004 11:19:06 +1200, "David Grant" <[email protected]>
> wrote:
>
>
>>Hi
>>
>>I have a similar problem - 1987 RRC Vogue 3.5EFI
>>
>>Driven 'around town' and on light throttle openings = excellent driving.
>>Fuel consumption = 17.5mph (round-town) - which I thought was generally OK.
>>BUT - on the open road perhaps with a gentle up-incline - push on the
>>accelerator
>>and power falls off - engine 'popping' 'mis-firing'
>>power drops until it is necessary to change down!!!!
>>Then get to back to 'light' throttle openings.
>>Done all the obvious things including spark plugs of 1 higher in heat range.
>>My analysis so far is that on light throttle the vacuum advance is keeping
>>the spark when/where it wants to be.
>>OR some problem with the air-flap thing which causes excess fuel injection.
>>Any hints/clues would be appreciated as I don't believe it taking things
>>apart on a 'just-in-case' basis.
>>
>>David
>>Christchurch, New Zealand.
>>
>
>
> It also sounds similar to the problem I had with the 101, which turned
> out to be an inlet manifold leak. What is it like when cold - does
> the problem get worse as the engine warms up?
>
> Could also be fuel starvation - if you are getting a backfire that
> would suggest it is running too lean at higher throttle. Possible
> causes there would be dicky fuel pump, blocked line, blocked filter
> etc etc.

Agreed. Could also be (lean wise) faulty PCV valve or leaky diaphragm
in the brake booster. If you want help/opinion a bit closer to home
(Auckland, and get to Chch from time to time) email me (unmunge as per
sig) or phone me on (027) 473-2631 during sociable daylight hours.


--
EMB
change two to number to reply

In <[email protected]> David Grant wrote:
> Hi
>
> I have a similar problem - 1987 RRC Vogue 3.5EFI
>
> Driven 'around town' and on light throttle openings = excellent
> driving. Fuel consumption = 17.5mph (round-town) - which I thought was
> generally OK. BUT - on the open road perhaps with a gentle up-incline -
> push on the accelerator and power falls off - engine 'popping' 'mis-
> firing' power drops until it is necessary to change down!!!! Then get
> to back to 'light' throttle openings. Done all the obvious things
> including spark plugs of 1 higher in heat range. My analysis so far is
> that on light throttle the vacuum advance is keeping the spark when/
> where it wants to be. OR some problem with the air-flap thing which
> causes excess fuel injection. Any hints/clues would be appreciated as
> I don't believe it taking things apart on a 'just-in-case' basis.
>
> David
> Christchurch, New Zealand.

My first candidate would be the fuel pump/system. This sounds like
classic fuel starvation problems. When was the fuel filter last changed ?
If you don't have a suitable pressure gauge to measure the fuel rail
pressure this can be difficult to diagnose without changing the pump.
You could divert the fuel return pipe and see if fuel is still being
returned when the engine starts missing. If the fuel return dries up
then the pump isn't delivering enough pressure/fuel.

Other than chacking for leaks, check the throttle position sensor (
throttle pot) and the air flow meter output. These are easy to check
with a multimeter. If you haven't got a manual that tells you how too
carry out the checks let me know and I'll p0ost a description.

On the ignition side, is it throttle position or rpm dependant ? If it's
rpm dependant then maybe the mechanical advance weights are seized.

cheers

Dave W.
http://www.yorkshireoffroadclub.net/

On Sat, 7 Aug 2004 11:19:06 +1200, "David Grant" <[email protected]>
wrote:

>Hi
>
>I have a similar problem - 1987 RRC Vogue 3.5EFI
>
>Driven 'around town' and on light throttle openings = excellent driving.
>Fuel consumption = 17.5mph (round-town) - which I thought was generally OK.
>BUT - on the open road perhaps with a gentle up-incline - push on the
>accelerator
>and power falls off - engine 'popping' 'mis-firing'
>power drops until it is necessary to change down!!!!
>Then get to back to 'light' throttle openings.
>Done all the obvious things including spark plugs of 1 higher in heat range.
>My analysis so far is that on light throttle the vacuum advance is keeping
>the spark when/where it wants to be.
>OR some problem with the air-flap thing which causes excess fuel injection.
>Any hints/clues would be appreciated as I don't believe it taking things
>apart on a 'just-in-case' basis.
>
>David
>Christchurch, New Zealand.
>

It also sounds similar to the problem I had with the 101, which turned
out to be an inlet manifold leak. What is it like when cold - does
the problem get worse as the engine warms up?

Could also be fuel starvation - if you are getting a backfire that
would suggest it is running too lean at higher throttle. Possible
causes there would be dicky fuel pump, blocked line, blocked filter
etc etc.
--

Tim Hobbs

'58 Series 2 88" aka "Stig"
'77 101FC Ambulance aka "Burrt"
'95 Discovery V8i aka "The Disco" (FOR SALE)
'03 Volvo V70

My Landies? http://www.seriesii.co.uk
Barcoding? http://www.bartec-systems.com
Tony Luckwill web archive at http://www.luckwill.com