Starts ok but no idle.
Discussion
Hi All
I have recently fitted new spark plugs, ignition coil, ign module, distributor cap, rotor arm, HT leads, done away with the extenders in favour of heat socks as part of ignition overhaul.
Cars has been running well with starting and idle also fans cutting in/out.
Without warning car starts ok but will not idle, as soon as I take my foot off accelerator the the engine just cuts out. Rover gauge shows no faults although the stepper motor will not open or close via the rover gauge. Also no sign of it moving when key removed from ignition,
Will the non working stepper motor be the cause of the engine cutting out? Or is there some other reason! Appreciate any comments.
Thank you.
I have recently fitted new spark plugs, ignition coil, ign module, distributor cap, rotor arm, HT leads, done away with the extenders in favour of heat socks as part of ignition overhaul.
Cars has been running well with starting and idle also fans cutting in/out.
Without warning car starts ok but will not idle, as soon as I take my foot off accelerator the the engine just cuts out. Rover gauge shows no faults although the stepper motor will not open or close via the rover gauge. Also no sign of it moving when key removed from ignition,
Will the non working stepper motor be the cause of the engine cutting out? Or is there some other reason! Appreciate any comments.
Thank you.
You can take stepper out and re connect it, watch it’s action, if it doesn’t pulse out it needs cleaning or replacing.
If it does pulse out be careful as it can unwind and spring off the motor.
You can always try dis connectin* battery for 30 seconds to re set Ecu as that sometimes helps and I always did this when messing with stepper but theoretically each time you switch off it should over pulse and bring it back to a zero position.
If it does pulse out be careful as it can unwind and spring off the motor.
You can always try dis connectin* battery for 30 seconds to re set Ecu as that sometimes helps and I always did this when messing with stepper but theoretically each time you switch off it should over pulse and bring it back to a zero position.
jojackson4 said:
My money is on a dead stepper then
Good luck in the quest of finding a new one that works
I have cleaned the stepper as mentioned previously, also done ecu reset and tried operating the stepper via rover gauge to no avail, Good luck in the quest of finding a new one that works
My question is if I fit a new stepper motor will this stop the engine from cutting out, at the moment I have to keep my foot on accelerator to keep the revs ticking over otherwise the engine just cuts out.
Yes.
The stepper motor is just another name for
Idle control valve
And as the name suggests.
If Rover Gauge can’t budge the pin it sounds seized, hold the stepper and as it tries to move you should feel the electrical pulses trying to move it. Clean the elec connector
Unwind the pin off the shaft and try cleaning it again is all I can think of. If you have another Tvr owner with a working stepper near by ask to check using there’s.
There is another aspect to idle control as in the BLACK BOX behind the speedo which receives a speed signal from the rear wheels and holds the revs slightly higher as you slow down, it should dispensable at about 5-10 mph and revs drop to 900 from there.
But ignore this for now as until you have a smooth stepper position movement you have problems.
The stepper motor is just another name for
Idle control valve
And as the name suggests.
If Rover Gauge can’t budge the pin it sounds seized, hold the stepper and as it tries to move you should feel the electrical pulses trying to move it. Clean the elec connector
Unwind the pin off the shaft and try cleaning it again is all I can think of. If you have another Tvr owner with a working stepper near by ask to check using there’s.
There is another aspect to idle control as in the BLACK BOX behind the speedo which receives a speed signal from the rear wheels and holds the revs slightly higher as you slow down, it should dispensable at about 5-10 mph and revs drop to 900 from there.
But ignore this for now as until you have a smooth stepper position movement you have problems.
Umm- The stepper should be fully wound back on a cold engine if you take it out and look at it. Odd it does not tick over at all though- if the stepper failed on a warm engine it should still be about 30% open. This wont be enough to allow the car to start properly without some throttle input, but once the engines warm the "stuck " 30% should be fine. ideally if the base idle is correct the stepper will never be in a totally closed position. Even if the the stepper fully shut, (this is not a normal situation at all- it means the base idle is too high) there should be some air getting past the base idle screw to allow the car to idle slowly. Mind you as you already say if RoverGauge wont move the stepper you do have an issue- +/ - 30 steps is a good value to try just to see things move.
Classic Chim said:
Yes.
The stepper motor is just another name for
Idle control valve
And as the name suggests.
If Rover Gauge can’t budge the pin it sounds seized, hold the stepper and as it tries to move you should feel the electrical pulses trying to move it. Clean the elec connector
Unwind the pin off the shaft and try cleaning it again is all I can think of. If you have another Tvr owner with a working stepper near by ask to check using there’s.
There is another aspect to idle control as in the BLACK BOX behind the speedo which receives a speed signal from the rear wheels and holds the revs slightly higher as you slow down, it should dispensable at about 5-10 mph and revs drop to 900 from there.
But ignore this for now as until you have a smooth stepper position movement you have problems.
Houston we have lift off, removed the pin off the shaft which until now didn’t realise could be unscrewed, sprayed some carburettor cleaner on it and inside connected back up to plenum turned the key removed key and stepper sprung back to life, started ignition and she’s running spot on.
Thank you for all the helpful comments
The stepper motor is just another name for
Idle control valve
And as the name suggests.
If Rover Gauge can’t budge the pin it sounds seized, hold the stepper and as it tries to move you should feel the electrical pulses trying to move it. Clean the elec connector
Unwind the pin off the shaft and try cleaning it again is all I can think of. If you have another Tvr owner with a working stepper near by ask to check using there’s.
There is another aspect to idle control as in the BLACK BOX behind the speedo which receives a speed signal from the rear wheels and holds the revs slightly higher as you slow down, it should dispensable at about 5-10 mph and revs drop to 900 from there.
But ignore this for now as until you have a smooth stepper position movement you have problems.
Houston we have lift off, removed the pin off the shaft which until now didn’t realise could be unscrewed, sprayed some carburettor cleaner on it and inside connected back up to plenum turned the key removed key and stepper sprung back to life, started ignition and she’s running spot on.
Thank you for all the helpful comments
jojackson4 said:
Not proven yet getmecoat:
Hmmm I’m being positive If it sticks once it’s likely to stick again I suppose
Carrera 800
it’s probably a good idea to clamp off the pipe going into the back of the Plenum and just check your base idle which should be about 600 revs.
900 with stepper working well.
Check Ecu and make sure it’s all dry down there.
Have you checked the fit of the king lead into the coil? Ask how I know this can be a problem! Really simple one but this can cause grief if not a good fit. In my case, the arcing buggered the end of the coil before the problem was diagnosed. New coil, (could have been avoided) end of problem.
(Yes, I know this is the same response to another thread - but worth checking in this instance too, I feel. Such a simple fix if it proves to be the culprit.)
(Yes, I know this is the same response to another thread - but worth checking in this instance too, I feel. Such a simple fix if it proves to be the culprit.)
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