Engine Problem with 3.5EFI Rangie

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.

They had the coil changed and this helped for 2 days before the problem came
back again. The plugs have all been changed and one garage it was into
removed the cold start injector which seemed to help a little.

I've never played with an EFI and so don't know the "normal" problems they
suffer from.

Given that this problem sounds like massive overfuelling or a major ignition
problem I'm leaning towards something being up with the distributor -
either the advance/retard doing stupid things and throwing the timing badly
off or the spark being particularly poor.

Any other ideas? The last resort is obviously to rip the whole EFI shooting
match off and fit carburettors, but that's a big job and it means getting
large chunks of carburetted V8 engine which will probably cost more than
it's worth by the time labour is factored in (I am *not* replacing the top
of a V8 again - once is enough)

P.

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.

Paul S. Brown wrote:

> 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.

Had a similar prob. with my '86 RR a few weeks ago. (Well, if finally died
and needed fixing...)

I'd been chasing the problem for months - changed throttle pot, dizzy, temp
sensors, etc.) with little improvement.

The culprit? The ECU!, oh yes, that little silver box under the drivers
seat.

Have you access to a known 'good' one? - most independant dealers have one
squirreled away for diagnostic use. When I replaced mine, the car ran
better than it'd ever done!

Cost me £350 for a genuine Lucas re-manufactured one. I've heard some pretty
dire stories (from several sources) about having them repaired, so I went
with a genuine one.

Hope this helps.

Horse

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/

> The culprit? The ECU!, oh yes, that little silver box under the drivers
> seat.

Had my ECU from the EFi RRC I once owned repaird by the company below,
the engine was overfuling all the time, black smoke and running rough,
sotty plugs etc. This cured the fault, but can't remember how much
they charged. http://www.carelect.demon.co.uk/rrp1.html

Alan C

Paul S. Brown wrote:

><SNIP A LOAD OF WAFFLE>

Took this rangie to my local Nationwide autocentre who took a look and said
"We think it's the air mass sensor, but we can't test it"

Took it to my local Franchised Non Franchise Specialist (go figure - owned
by a franchise, staffed by the same guys, doesn't actually have a franchise
itself and costs half as much)

They took it to bits, bridged out various sensors under the bonnet which
made no difference to the running and suggested it was probably an ECU
fault, but they didn't have a good 4CU to test against.

So, I go prodding around to figure out how difficult the ECU would be to
replace (not very as it turns out) and accidentally dislodge the multiplug
from it. Plug it back in and get in the car.

It's not misfiring. It's not hunting, it's not blowing vast clouds of smoke.

Could it really all have just been a connector fault into the ECU? Would be
nice if it was, but I'd have hoped that somebody else would have checked
that.

P.