well back out to you lot ... stalling
Discussion
right fixed the rev counter issue (fingers crossed... it was the ignition amp)..... BUT now back to the initial problem of it stalling cutting out at junctions....
recently replaced fuel relays, temp sensor, ignition amp... and hap plenum.butterfly enlarged
at times it pulls like a train, and is big smiles...... then something changes and engine spins up but delivering power as it should...... and then approaching junctions the revs die... and 9/10 engine cuts out
am I still heading towards junking lucas ?????
Part of me feels there is 300bhp in this engine, but I want running correct;y firts
recently replaced fuel relays, temp sensor, ignition amp... and hap plenum.butterfly enlarged
at times it pulls like a train, and is big smiles...... then something changes and engine spins up but delivering power as it should...... and then approaching junctions the revs die... and 9/10 engine cuts out
am I still heading towards junking lucas ?????
Part of me feels there is 300bhp in this engine, but I want running correct;y firts
Those symptoms are commonly bad air leaks, spray round the plenum and you'll like hear the engine note change. I'd just remove the plenum & rebuild carefully going on what you said about having the plenum Butterfly enlarged ~ particularly that the bypasses & hose connectors are all OK as well as resealing the joint twixt plenum & base.
TimJM said:
Stepper motor is my guess. Mine did the very same thing last year. Would run spot on but die at every junction. A new stepper motor and it was all fine again.
oh...and a lambda sensor looking at the invoice...and new plugs...Does your's also have sticky high revs? My revs used to stick at 2-2.5k and take 20-30 seconds to drop but this was when starting it up and backing it out of my drive. Once I was on a run the revs would either stick at 2-2.5k or drop to 0 and stall at every junction. But, 9/10 it was drop to 0 like you described.
A lazy stepper. A clean, including the base fitting and a WD40 spray on the plunger. Dismantle and clean see http://www.rv8r.co.uk/tickover.html
Hi Hoover, for what it's worth here's my advice:
GETTING THE BASICS RIGHT FIRST
I'd start by following the correct procedure for setting your base idle & throttle pot.
http://www.actproducts.co.uk/2011/lucas-14cux-fuel...
Getting your base idle right is an essential starting point before you move on to diagnosing the fault, ignore this step & you could be chasing your tail for ever!
THE MUCH MALIGNED STEPPER MOTOR
Many on here will tell you to clean your stepper motor.
http://www.parkersteve.dsl.pipex.com/stepper.html
While this can help in some cases, it's important to remember the stepper motor is essentially a dumb unit, it's very short sighted to blame this dumb unit for all idle & stalling issues.
What you need to consider is what controls the stepper motor, the ECU!
More than that, you need to understand what signals the ECU is using to make up it's mind what it wants to tell the dumb stepper motor to do.
OTHER THINGS TO CONSIDER
For example, is your speedo working correctly?
If not the ECU will not be getting the low speed signal it needs to reinstate fuel and adjust the bleed of air needed to stop the car stalling at junctions.
If the problem persists suspect the problematic TVR speed signal device under the dash.
I had this problem & traced it to a bad connection at the back of the speedo head, the speed signal box needs a signal from the speedo.
And the ECU needs the manipulated signal output produced by the speed signal box to know if you are approaching a junction.
If the ECU is not getting this lower than 5mph signal (for whatever reason) you will stall at junctions as it will be restricting air because it'll be instructing the stepper motor to operate in the "smoother gear change mode".
REMEMBER THE BASICS
But dont just jump straight the the speed signal idea.
It's essential to get the basics right first by correctly setting your base idle & throttle pot
THINK SMART
Like any system, you can only fix it if you properly understand how it works
Good luck, & dont forget to let us all know how you get on
GETTING THE BASICS RIGHT FIRST
I'd start by following the correct procedure for setting your base idle & throttle pot.
http://www.actproducts.co.uk/2011/lucas-14cux-fuel...
Getting your base idle right is an essential starting point before you move on to diagnosing the fault, ignore this step & you could be chasing your tail for ever!
THE MUCH MALIGNED STEPPER MOTOR
Many on here will tell you to clean your stepper motor.
http://www.parkersteve.dsl.pipex.com/stepper.html
While this can help in some cases, it's important to remember the stepper motor is essentially a dumb unit, it's very short sighted to blame this dumb unit for all idle & stalling issues.
What you need to consider is what controls the stepper motor, the ECU!
More than that, you need to understand what signals the ECU is using to make up it's mind what it wants to tell the dumb stepper motor to do.
OTHER THINGS TO CONSIDER
For example, is your speedo working correctly?
If not the ECU will not be getting the low speed signal it needs to reinstate fuel and adjust the bleed of air needed to stop the car stalling at junctions.
If the problem persists suspect the problematic TVR speed signal device under the dash.
I had this problem & traced it to a bad connection at the back of the speedo head, the speed signal box needs a signal from the speedo.
And the ECU needs the manipulated signal output produced by the speed signal box to know if you are approaching a junction.
If the ECU is not getting this lower than 5mph signal (for whatever reason) you will stall at junctions as it will be restricting air because it'll be instructing the stepper motor to operate in the "smoother gear change mode".
REMEMBER THE BASICS
But dont just jump straight the the speed signal idea.
It's essential to get the basics right first by correctly setting your base idle & throttle pot
THINK SMART
Like any system, you can only fix it if you properly understand how it works
Good luck, & dont forget to let us all know how you get on
Edited by ChimpOnGas on Wednesday 17th April 09:00
Hoover, dont you have a T5 box. In which case when the conversion was done from the LT77 they must have added the signal conversion box thingy for the ecu to get its road speed signal. The LT77 had its own which screws into the gearbox. You wouldnt be able to use this on your T5. Maybe something has gone astray with whatever they did to get the road speed signal. I would be looking for this.
IF this is the problem a new ecu would however solve this as you would have a crank trigger wheel to give you your signal.
IF this is the problem a new ecu would however solve this as you would have a crank trigger wheel to give you your signal.
Sorry to hear you are having problems again Hoover. The Griff was certainly performing well on the drive down to Morgan on Monday.
I think Alex has cursed our Griffs as mine kept cutting out on the way home.
Sometimes it would just missifre and other times die completely, coast it into the hard shoulder, wait for a minute, restart and drive fine for another 30 odd miles. WTF. To make matters worse the left indicator has packed up so signalling to other motorists that I need to quickly go from lane 3 to the hard shoulder is challenging. I get back home and of course the indicator that has not worked for the last 150 miles now works fine. Bloody car!
I think Alex has cursed our Griffs as mine kept cutting out on the way home.
Sometimes it would just missifre and other times die completely, coast it into the hard shoulder, wait for a minute, restart and drive fine for another 30 odd miles. WTF. To make matters worse the left indicator has packed up so signalling to other motorists that I need to quickly go from lane 3 to the hard shoulder is challenging. I get back home and of course the indicator that has not worked for the last 150 miles now works fine. Bloody car!MPoxon said:
Sorry to hear you are having problems again Hoover. The Griff was certainly performing well on the drive down to Morgan on Monday.
I think Alex has cursed our Griffs as mine kept cutting out on the way home. Sometimes it would just missifre and other times die completely, coast it into the hard shoulder, wait for a minute, restart and drive fine for another 30 odd miles. WTF. To make matters worse the left indicator has packed up so signalling to other motorists that I need to quickly go from lane 3 to the hard shoulder is challenging. I get back home and of course the indicator that has not worked for the last 150 miles now works fine. Bloody car!
That's the dreaded immobiliser for sure MPoxon.I think Alex has cursed our Griffs as mine kept cutting out on the way home.
Sometimes it would just missifre and other times die completely, coast it into the hard shoulder, wait for a minute, restart and drive fine for another 30 odd miles. WTF. To make matters worse the left indicator has packed up so signalling to other motorists that I need to quickly go from lane 3 to the hard shoulder is challenging. I get back home and of course the indicator that has not worked for the last 150 miles now works fine. Bloody car!The fuel pump & other circuits are routed through the immobiliser, which TVR wired back to front
It sounds like your immobiliser is cutting your fuel, the immobiliser is also connected to the indicator circuits to flash them when you lock the car.
So indicator strangeness & cutting out together both clearly points to an immobiliser/alarm system issues.
PM me, I can help.
Replacing the lucas because you cant fix it ?- and expensive way of diagnostics. Bite the bullet and spend between £35 to £135 on some diagnostic gear.
Then you can:
1)Test the stepper operation open / close
2)Check the stepper postion at idle (this has relevence to the base idle setting)
2)Check for errant speed signals.
3)Check throttle pot operation.
All of the above affect the idle before you go and spend a Grand on an aftermarket ECU.
The base idle is supposed to be set at 525 +/- 25 rpm with the air feed to the stepper blocked- realistically a TVR motor wont idle that low, so just get it as low as you can. A good base idle seems to give a stepper reading between 30-40% open at idle.
The issue of the speed conversion box is due to the circuit design being prone to producing a speed signal if the earth pin has any residule voltages or spikes on it, which is quite likely when the earth wiring gets corroded- so check all the grounding straps. Mind you a faulty speed signal causes a raised idle, not a low one.
Then you can:
1)Test the stepper operation open / close
2)Check the stepper postion at idle (this has relevence to the base idle setting)
2)Check for errant speed signals.
3)Check throttle pot operation.
All of the above affect the idle before you go and spend a Grand on an aftermarket ECU.
The base idle is supposed to be set at 525 +/- 25 rpm with the air feed to the stepper blocked- realistically a TVR motor wont idle that low, so just get it as low as you can. A good base idle seems to give a stepper reading between 30-40% open at idle.
The issue of the speed conversion box is due to the circuit design being prone to producing a speed signal if the earth pin has any residule voltages or spikes on it, which is quite likely when the earth wiring gets corroded- so check all the grounding straps. Mind you a faulty speed signal causes a raised idle, not a low one.
blitzracing said:
Replacing the lucas because you cant fix it ?- and expensive way of diagnostics. Bite the bullet and spend between £35 to £135 on some diagnostic gear.
Then you can:
1)Test the stepper operation open / close
2)Check the stepper postion at idle (this has relevence to the base idle setting)
2)Check for errant speed signals.
3)Check throttle pot operation.
All of the above affect the idle before you go and spend a Grand on an aftermarket ECU.
The base idle is supposed to be set at 525 +/- 25 rpm with the air feed to the stepper blocked- realistically a TVR motor wont idle that low, so just get it as low as you can. A good base idle seems to give a stepper reading between 30-40% open at idle.
The issue of the speed conversion box is due to the circuit design being prone to producing a speed signal if the earth pin has any residule voltages or spikes on it, which is quite likely when the earth wiring gets corroded- so check all the grounding straps. Mind you a faulty speed signal causes a raised idle, not a low one.
You can adjust the base idle if you like ~ but if there are air leaks you will just be fThen you can:
1)Test the stepper operation open / close
2)Check the stepper postion at idle (this has relevence to the base idle setting)
2)Check for errant speed signals.
3)Check throttle pot operation.
All of the above affect the idle before you go and spend a Grand on an aftermarket ECU.
The base idle is supposed to be set at 525 +/- 25 rpm with the air feed to the stepper blocked- realistically a TVR motor wont idle that low, so just get it as low as you can. A good base idle seems to give a stepper reading between 30-40% open at idle.
The issue of the speed conversion box is due to the circuit design being prone to producing a speed signal if the earth pin has any residule voltages or spikes on it, which is quite likely when the earth wiring gets corroded- so check all the grounding straps. Mind you a faulty speed signal causes a raised idle, not a low one.
king it up even more... I'm pretty sure if you actually read the Rover diagnostics they will always stress to check for air leaks FIRST.ChimpOnGas said:
That's the dreaded immobiliser for sure MPoxon.
The fuel pump & other circuits are routed through the immobiliser, which TVR wired back to front
It sounds like your immobiliser is cutting your fuel, the immobiliser is also connected to the indicator circuits to flash them when you lock the car.
So indicator strangeness & cutting out together both clearly points to an immobiliser/alarm system issues.
PM me, I can help.
Hi ChimpOnGas,The fuel pump & other circuits are routed through the immobiliser, which TVR wired back to front
It sounds like your immobiliser is cutting your fuel, the immobiliser is also connected to the indicator circuits to flash them when you lock the car.
So indicator strangeness & cutting out together both clearly points to an immobiliser/alarm system issues.
PM me, I can help.
I don't believe the immobiliser is the issue as I had a brand new Meta Alarm system fitted by Carl Baker a few years ago and this cured all by hot start and immobiliser woes. Last time this happened it turned out to be an issue with the wiring loom.
I will try the obvious relays and clean all the connectors I can find with contact cleaner first. If the issue is still there I will start another thread as I don't want to hijack Hoover's thread.
Thank you very much for your reply and offer of help - much appreciated
Matthew
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