Poorly V8

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LEE ARGYLE

Guest
Some advice from the V8 genius's please.......

3.9i V8, every time you approach 2900/3000 revs accelerating with half
throttle the engine faulters........and continues to do so as the rev's
increase.
Upto 3k its perfect - power, torque whatever the load/throttle setting!

So I changed the cap, HT leads, rotor arm, ignition module, coil - no joy,
so popped a new complete distributor on and swapped the ECU - still the same
fault.

I also checked the vacuum pipe from the inlet manifold to the dizzy and that
seems fine (using strobe gun the timing changes with revving)


What am I missing (no tdi jokes please)

Thanks in advance


Lee






 

"LEE ARGYLE" <[email protected]> wrote in message
news:[email protected]...
> Some advice from the V8 genius's please.......
>
> 3.9i V8, every time you approach 2900/3000 revs accelerating with half
> throttle the engine faulters........and continues to do so as the rev's
> increase.
> Upto 3k its perfect - power, torque whatever the load/throttle setting!
>
> So I changed the cap, HT leads, rotor arm, ignition module, coil - no joy,
> so popped a new complete distributor on and swapped the ECU - still the
> same
> fault.
>
> I also checked the vacuum pipe from the inlet manifold to the dizzy and
> that
> seems fine (using strobe gun the timing changes with revving)
>
>
> What am I missing (no tdi jokes please)
>
> Thanks in advance
>
>
> Lee
>
>

Just as a quickie Lee, when was the fuel filters last replaced?
Badger.


 
Not checked filter/s yet - you think it might be a fuel pressure problem?

Regards


Lee
"Badger" <[email protected]> wrote in message
news:[email protected]...
>
> "LEE ARGYLE" <[email protected]> wrote in message
> news:[email protected]...
> > Some advice from the V8 genius's please.......
> >
> > 3.9i V8, every time you approach 2900/3000 revs accelerating with half
> > throttle the engine faulters........and continues to do so as the rev's
> > increase.
> > Upto 3k its perfect - power, torque whatever the load/throttle setting!
> >
> > So I changed the cap, HT leads, rotor arm, ignition module, coil - no

joy,
> > so popped a new complete distributor on and swapped the ECU - still the
> > same
> > fault.
> >
> > I also checked the vacuum pipe from the inlet manifold to the dizzy and
> > that
> > seems fine (using strobe gun the timing changes with revving)
> >
> >
> > What am I missing (no tdi jokes please)
> >
> > Thanks in advance
> >
> >
> > Lee
> >
> >

> Just as a quickie Lee, when was the fuel filters last replaced?
> Badger.
>
>



 
On or around Tue, 4 Jan 2005 21:57:55 +0000 (UTC), "LEE ARGYLE"
<[email protected]> enlightened us thusly:

>Some advice from the V8 genius's please.......
>
>3.9i V8, every time you approach 2900/3000 revs accelerating with half
>throttle the engine faulters........and continues to do so as the rev's
>increase.
>Upto 3k its perfect - power, torque whatever the load/throttle setting!
>
>So I changed the cap, HT leads, rotor arm, ignition module, coil - no joy,
>so popped a new complete distributor on and swapped the ECU - still the same
>fault.
>
>I also checked the vacuum pipe from the inlet manifold to the dizzy and that
>seems fine (using strobe gun the timing changes with revving)
>
>
>What am I missing (no tdi jokes please)


pipe from the AFM to the manifold OK?

but I have to say, Badger has a likely-sounding option in the fuel supply.

will it actually pull decently at higher revs, or does it run out of go?


--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
Soon shall thy arm, unconquered steam! afar Drag the slow barge, or
drive the rapid car; Or on wide-waving wings expanded bear the
flying chariot through the field of air.- Erasmus Darwin (1731-1802)
 
Hi Badger


Still struggling with the V8, fitted a new fuel pump - loads of pressure,
still the same fault......
Borrowed a airflow meter from a mates Range Rover and no change, get to 3k
and she starts faltering!!!!

Any ideas or do you know who I can contact for help


Regards


Lee



"Badger" <[email protected]> wrote in message
news:[email protected]...
>
> "LEE ARGYLE" <[email protected]> wrote in message
> news:[email protected]...
> > Not checked filter/s yet - you think it might be a fuel pressure

problem?
> >

> It's a landrover product, anything is possible!!
> Badger.
>
>



 
Hi there LEE

Just a thought but if you have a defender (or any other i guess ) there is
the earth connection on the bulk head that all the EFI wiring earths
through. As i remember its approx three earth wires connected into one
crimp, this maybe loose and causing your problem. I've found this problem on
a few Landies now so worth a look! Connection is drivers side just off from
center.

Also another thought check your alternator is giving out the correct
voltage! 12-14.4v you could have one thats over voltage usually 17volts.

Then i guess a ring round any of the specialists i guess RPI or JE
developments.

JE developments seem good lads from what i've heard and experienced! Ask for
Richard or John on 01455 202909


"LEE ARGYLE" <[email protected]> wrote in message
news:[email protected]...
> Some advice from the V8 genius's please.......
>
> 3.9i V8, every time you approach 2900/3000 revs accelerating with half
> throttle the engine faulters........and continues to do so as the rev's
> increase.
> Upto 3k its perfect - power, torque whatever the load/throttle setting!
>
> So I changed the cap, HT leads, rotor arm, ignition module, coil - no joy,
> so popped a new complete distributor on and swapped the ECU - still the
> same
> fault.
>
> I also checked the vacuum pipe from the inlet manifold to the dizzy and
> that
> seems fine (using strobe gun the timing changes with revving)
>
>
> What am I missing (no tdi jokes please)
>
> Thanks in advance
>
>
> Lee
>
>
>
>
>
>



 
On or around Thu, 6 Jan 2005 21:39:29 +0000 (UTC), "LEE ARGYLE"
<[email protected]> enlightened us thusly:

>Hi Badger
>
>
>Still struggling with the V8, fitted a new fuel pump - loads of pressure,
>still the same fault......
>Borrowed a airflow meter from a mates Range Rover and no change, get to 3k
>and she starts faltering!!!!
>
>Any ideas or do you know who I can contact for help


You have got the correct coil, I assume, viz. one intended for an electronic
ignition system if you have an electronic distributor?

that can give some very funny faults.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"My centre is giving way, my right is in retreat; situation excellent.
I shall attack. - Marshal Foch (1851 - 1929)
 

"LEE ARGYLE" <[email protected]> wrote in message
news:[email protected]...
> Hi Badger
>
>
> Still struggling with the V8, fitted a new fuel pump - loads of pressure,
> still the same fault......
> Borrowed a airflow meter from a mates Range Rover and no change, get to 3k
> and she starts faltering!!!!
>
> Any ideas or do you know who I can contact for help
>
>

Next thing I'd want to try would be an ecu swap just to see if it made any
difference, but then you say that's been done already.
If it's getting enough fuel then I'd say that it has to be something
directly related to rpm, and it can't be throttle position or airflow if it
takes any ammount of throttle below the problem rpm threshold - so that
rules out the throttle pot and the afm.
My next move would have been the dizzy module, but that's been done also!
Just a thought, where does the ecu get it's rpm signal from on this model?
If it's the coil, (and most are, very rare to trigger an ecu from an
alternator rpm take-off) stick a meter (set to frequency) at the coil and
see if the frequency rises smoothly with rpm. If the readings go doo-lally
at 3000 then it's a low-tension ignition triggering issue. Hang on, here's a
thought; you could also fit a strobe gun and have an assistant raise the rpm
and see what happens. If the sparks go mad at 3000 then at least you've tied
it down to the ignition or fuel system - one way or another.
Good luck,
Badger.


 
Well, think I've fixed it.........
Spent the last three hours fiddling, testing, swapping and
praying.....................

Proved the ignition was to blame - strobe gun dieing when rev's reach
certain point (3k).
Checked and re-checked the HT & LT circuits, stripped the dizzy etc etc.
However with Mr Multi-Meter I found that although the coil live was 12v with
idling it dropped down to 9v when revved????? Took a new live straight from
the battery and onto the coil - didn't miss a beat and pulls like a
train!!!!

Big thankyou for the advice/tips!!!


Regards


Lee
"Jinx" <[email protected]> wrote in message
news:[email protected]...
> Hi there LEE
>
> Just a thought but if you have a defender (or any other i guess ) there is
> the earth connection on the bulk head that all the EFI wiring earths
> through. As i remember its approx three earth wires connected into one
> crimp, this maybe loose and causing your problem. I've found this problem

on
> a few Landies now so worth a look! Connection is drivers side just off

from
> center.
>
> Also another thought check your alternator is giving out the correct
> voltage! 12-14.4v you could have one thats over voltage usually 17volts.
>
> Then i guess a ring round any of the specialists i guess RPI or JE
> developments.
>
> JE developments seem good lads from what i've heard and experienced! Ask

for
> Richard or John on 01455 202909
>
>
> "LEE ARGYLE" <[email protected]> wrote in message
> news:[email protected]...
> > Some advice from the V8 genius's please.......
> >
> > 3.9i V8, every time you approach 2900/3000 revs accelerating with half
> > throttle the engine faulters........and continues to do so as the rev's
> > increase.
> > Upto 3k its perfect - power, torque whatever the load/throttle setting!
> >
> > So I changed the cap, HT leads, rotor arm, ignition module, coil - no

joy,
> > so popped a new complete distributor on and swapped the ECU - still the
> > same
> > fault.
> >
> > I also checked the vacuum pipe from the inlet manifold to the dizzy and
> > that
> > seems fine (using strobe gun the timing changes with revving)
> >
> >
> > What am I missing (no tdi jokes please)
> >
> > Thanks in advance
> >
> >
> > Lee
> >
> >
> >
> >
> >
> >

>
>



 

"LEE ARGYLE" <[email protected]> wrote in message
news:[email protected]...
> Well, think I've fixed it.........
> Spent the last three hours fiddling, testing, swapping and
> praying.....................
>
> Proved the ignition was to blame - strobe gun dieing when rev's reach
> certain point (3k).
> Checked and re-checked the HT & LT circuits, stripped the dizzy etc etc.
> However with Mr Multi-Meter I found that although the coil live was 12v
> with
> idling it dropped down to 9v when revved????? Took a new live straight
> from
> the battery and onto the coil - didn't miss a beat and pulls like a
> train!!!!
>
> Big thankyou for the advice/tips!!!
>

Glad you got it fixed mate.
Badger.


 
> Well, think I've fixed it.........
> Spent the last three hours fiddling, testing, swapping and
> praying.....................
>
> Proved the ignition was to blame - strobe gun dieing when rev's reach
> certain point (3k).
> Checked and re-checked the HT & LT circuits, stripped the dizzy etc etc.
> However with Mr Multi-Meter I found that although the coil live was 12v with
> idling it dropped down to 9v when revved????? Took a new live straight from
> the battery and onto the coil - didn't miss a beat and pulls like a
> train!!!!


I'll admit to not having read the beginning of this thread but this is
beginning to sound familiar.

Some of the RR coils are normally fed through a resistive wire i.e. run
at less than 12v in normal use. When starting a 'full' 12v feed is
supplied direct to the coil from the a terminal usually on the starter
motor itself.

What if the original coil (which is effectively a 9v coil) had been
replaced by a normal 12v coil and was still being fed through the
resistive wire? Sounds a reasonable explanation for your ills.

But, well diagnosed. It's a very satisfying feeling isn't it?

David

 
On or around Sat, 08 Jan 2005 17:34:54 +0000, Dougal
<DougalAThiskennel.free-online.co.uk> enlightened us thusly:

>
>Some of the RR coils are normally fed through a resistive wire i.e. run
>at less than 12v in normal use. When starting a 'full' 12v feed is
>supplied direct to the coil from the a terminal usually on the starter
>motor itself.
>
>What if the original coil (which is effectively a 9v coil) had been
>replaced by a normal 12v coil and was still being fed through the
>resistive wire? Sounds a reasonable explanation for your ills.
>
>But, well diagnosed. It's a very satisfying feeling isn't it?


if it's a points-based one with ballast, then this is always a possibility.

not sure any of the electronic dizzys are like that. I do know that you
have to have the right coil, though - electronic coil on a points dizzy gets
very hot rather quickly IME.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"The great masses of the people ... will more easily fall victims to
a great lie than to a small one" Adolf Hitler (1889 - 1945)
from Mein Kampf, Ch 10
 
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