Weird non-start issue
Discussion
Hi Folks,
Anyone give me a bright idea for this one please?
Car failed MOT on nearside headlamp beam. Put it up on my ramps, accessed via the nearside wheelarch and fixed it.
Due for retest tomorrow morning and now won't start. It turned over briefly then there was a clunk and clicking like the starter motor was being turned on and off.
Symptoms now:
1. The fuel pump doesn't always prime when the key is turned. Sometimes it does sometime it doesn't. When it does prime, it only runs for a fraction of the normal time then I think the relay shuts it off.
2. The engine will turn over for a second but then the starter cuts out sharply like you've let the key go. Occassionally, the starter cuts in and out rapidly after it cuts out.
3. The stepper motor buzzes a few seconds after the ignition is turned on and nothing when its turned off. Isn't it normally the other way around?
Thought it might have been the battery as had the lights on to adjust the beam.
But battery volts are fine. Engine turns over quickly before it sharply stops after about a second. Not a slow turnover and stop like when the battery is flat. Plus, you can repeat this process and exactly the same thing happens, no reduction in turnover speed and exactly same length of time before the starter is cut.
Have tried swapping out the ignition and fuel relays for a new one - no change. Tested relay coil resistances and contact resistance and all OK.
If fuel pump knackered then I thought the engine would just turn over continuously and not start.
Will the ECU cut the starter if the fuel pressure isn't right?
Can't think what I can have disturbed adjusting a headlamp. I moved wiring about in the nearside wing but nothing there to do with starting as far as I know. I moved the wiring around in the footwell slightly whilst trying to find the exciter wire for the solenoid as thinking of changing the wire out for a larger one (as my other recent thread).
If the starter / solenoid was bust then the fuel pump would still prime.
What else would cause the starter to cut once its started?
The alarm / immobiliser is a relatively new META unit. Replaced it under the guidance of Carl and has worked fine.
Have tried locking and unlocking the car to reset the alarm / immobiliser in case it was that. No change.
Will Rovergauge help diagnose anything for a starting issue? Any fault codes of use?
Thanks in advance.
Anyone give me a bright idea for this one please?
Car failed MOT on nearside headlamp beam. Put it up on my ramps, accessed via the nearside wheelarch and fixed it.
Due for retest tomorrow morning and now won't start. It turned over briefly then there was a clunk and clicking like the starter motor was being turned on and off.
Symptoms now:
1. The fuel pump doesn't always prime when the key is turned. Sometimes it does sometime it doesn't. When it does prime, it only runs for a fraction of the normal time then I think the relay shuts it off.
2. The engine will turn over for a second but then the starter cuts out sharply like you've let the key go. Occassionally, the starter cuts in and out rapidly after it cuts out.
3. The stepper motor buzzes a few seconds after the ignition is turned on and nothing when its turned off. Isn't it normally the other way around?
Thought it might have been the battery as had the lights on to adjust the beam.
But battery volts are fine. Engine turns over quickly before it sharply stops after about a second. Not a slow turnover and stop like when the battery is flat. Plus, you can repeat this process and exactly the same thing happens, no reduction in turnover speed and exactly same length of time before the starter is cut.
Have tried swapping out the ignition and fuel relays for a new one - no change. Tested relay coil resistances and contact resistance and all OK.
If fuel pump knackered then I thought the engine would just turn over continuously and not start.
Will the ECU cut the starter if the fuel pressure isn't right?
Can't think what I can have disturbed adjusting a headlamp. I moved wiring about in the nearside wing but nothing there to do with starting as far as I know. I moved the wiring around in the footwell slightly whilst trying to find the exciter wire for the solenoid as thinking of changing the wire out for a larger one (as my other recent thread).
If the starter / solenoid was bust then the fuel pump would still prime.
What else would cause the starter to cut once its started?
The alarm / immobiliser is a relatively new META unit. Replaced it under the guidance of Carl and has worked fine.
Have tried locking and unlocking the car to reset the alarm / immobiliser in case it was that. No change.
Will Rovergauge help diagnose anything for a starting issue? Any fault codes of use?
Thanks in advance.
Edited by taylormj4 on Monday 16th June 22:49
Edited by taylormj4 on Tuesday 17th June 00:40
Have now found that there is a 70A 'Ignition Feeds Relay' in the fuse panel. Is that in addition to the two relays (ignition and fuel pump) the float about in the loom in the footwell? Could that be at fault? Pulled it out and tested the coil. Had resistance of around 69ohms from memory.
Sounds like a poor connection to the battery to me, remove the terminals and check for corrosion on them and the battery posts, make sure they are pushed on all the way and nice and tight too.
If that is ok then just check all the connections down there are good.
I cant remember if the fuel pump primes every time you cycle the ignition when testing, after it does prime it wont run again until it sees the engine turning.
I would fault find on the starter circuit first though as you seem to have had previous problems with that, you can run a temporary solenoid trigger cable for test purposes.
If that is ok then just check all the connections down there are good.
I cant remember if the fuel pump primes every time you cycle the ignition when testing, after it does prime it wont run again until it sees the engine turning.
I would fault find on the starter circuit first though as you seem to have had previous problems with that, you can run a temporary solenoid trigger cable for test purposes.
RESOLVED
Thanks to suggestion from Carl. Was low battery in the immobiliser ID tag. So the immobiliser was cutting the starter and preventing the fuel pump priming.
Odd behaviour though the way it does it though. You'd think if it were immobilised, the starter would never turn and the fuel pump would never prime but instead it allows the starter to turn for a second then cuts it and for some reason allows the pump to part prime before cutting it out. Sometimes the starter is going off/on/off/on. Not what you expect and not intuitive for fault finding. Checked all sorts last night: wiring, relays, connections, pump, earths
.
All not helped by the conincedence of me having just done the headlamp realignment and presuming that I must have disturbed / broken something.
Use the spare ID tag and the fuel pump primes and starter operates as normal. However, now have a noisy tapping coming from the offside rocker. Presuming this is a hydraulic lifter, maybe due to lots of cranking with the nose high on ramps.
I just wanted to get it MOT'd
it only failed on headlamp aim.
Thanks to suggestion from Carl. Was low battery in the immobiliser ID tag. So the immobiliser was cutting the starter and preventing the fuel pump priming.
Odd behaviour though the way it does it though. You'd think if it were immobilised, the starter would never turn and the fuel pump would never prime but instead it allows the starter to turn for a second then cuts it and for some reason allows the pump to part prime before cutting it out. Sometimes the starter is going off/on/off/on. Not what you expect and not intuitive for fault finding. Checked all sorts last night: wiring, relays, connections, pump, earths
.All not helped by the conincedence of me having just done the headlamp realignment and presuming that I must have disturbed / broken something.
Use the spare ID tag and the fuel pump primes and starter operates as normal. However, now have a noisy tapping coming from the offside rocker. Presuming this is a hydraulic lifter, maybe due to lots of cranking with the nose high on ramps.
I just wanted to get it MOT'd
it only failed on headlamp aim.taylormj4 said:
RESOLVED
Thanks to suggestion from Carl. Was low battery in the immobiliser ID tag. So the immobiliser was cutting the starter and preventing the fuel pump priming.
Odd behaviour though the way it does it though. You'd think if it were immobilised, the starter would never turn and the fuel pump would never prime but instead it allows the starter to turn for a second then cuts it and for some reason allows the pump to part prime before cutting it out. Sometimes the starter is going off/on/off/on. Not what you expect and not intuitive for fault finding. Checked all sorts last night: wiring, relays, connections, pump, earths.
All not helped by the conincedence of me having just done the headlamp realignment and presuming that I must have disturbed / broken something.
Use the spare ID tag and the fuel pump primes and starter operates as normal. However, now have a noisy tapping coming from the offside rocker. Presuming this is a hydraulic lifter, maybe due to lots of cranking with the nose high on ramps.
I just wanted to get it MOT'd it only failed on headlamp aim.
Dont ignore a loud tapping on these engines it may not be just a sticky lifter etc , sudden like maybe a failed/sheared rocker arm pad in time this mushrooms/wrecks the valve stem causing further costs and grief , one from my black museum "customers 5.0 Griff with just 32k miles" many moons ago Thanks to suggestion from Carl. Was low battery in the immobiliser ID tag. So the immobiliser was cutting the starter and preventing the fuel pump priming.
Odd behaviour though the way it does it though. You'd think if it were immobilised, the starter would never turn and the fuel pump would never prime but instead it allows the starter to turn for a second then cuts it and for some reason allows the pump to part prime before cutting it out. Sometimes the starter is going off/on/off/on. Not what you expect and not intuitive for fault finding. Checked all sorts last night: wiring, relays, connections, pump, earths
.All not helped by the conincedence of me having just done the headlamp realignment and presuming that I must have disturbed / broken something.
Use the spare ID tag and the fuel pump primes and starter operates as normal. However, now have a noisy tapping coming from the offside rocker. Presuming this is a hydraulic lifter, maybe due to lots of cranking with the nose high on ramps.
I just wanted to get it MOT'd
it only failed on headlamp aim.taylormj4 said:
RESOLVED
Thanks to suggestion from Carl. Was low battery in the immobiliser ID tag. So the immobiliser was cutting the starter and preventing the fuel pump priming.
Odd behaviour though the way it does it though. You'd think if it were immobilised, the starter would never turn and the fuel pump would never prime but instead it allows the starter to turn for a second then cuts it and for some reason allows the pump to part prime before cutting it out. Sometimes the starter is going off/on/off/on. Not what you expect and not intuitive for fault finding. Checked all sorts last night: wiring, relays, connections, pump, earths.
All not helped by the conincedence of me having just done the headlamp realignment and presuming that I must have disturbed / broken something.
Use the spare ID tag and the fuel pump primes and starter operates as normal. However, now have a noisy tapping coming from the offside rocker. Presuming this is a hydraulic lifter, maybe due to lots of cranking with the nose high on ramps.
I just wanted to get it MOT'd it only failed on headlamp aim.
Not sure i buy that as normal behaviour from the immobiliser, it will burn contacts out in relays etc in no time.Thanks to suggestion from Carl. Was low battery in the immobiliser ID tag. So the immobiliser was cutting the starter and preventing the fuel pump priming.
Odd behaviour though the way it does it though. You'd think if it were immobilised, the starter would never turn and the fuel pump would never prime but instead it allows the starter to turn for a second then cuts it and for some reason allows the pump to part prime before cutting it out. Sometimes the starter is going off/on/off/on. Not what you expect and not intuitive for fault finding. Checked all sorts last night: wiring, relays, connections, pump, earths
.All not helped by the conincedence of me having just done the headlamp realignment and presuming that I must have disturbed / broken something.
Use the spare ID tag and the fuel pump primes and starter operates as normal. However, now have a noisy tapping coming from the offside rocker. Presuming this is a hydraulic lifter, maybe due to lots of cranking with the nose high on ramps.
I just wanted to get it MOT'd
it only failed on headlamp aim.Sardonicus said:
ont ignore a loud tapping on these engines it may not be just a sticky lifter etc , sudden like maybe a failed/sheared rocker arm pad in time this mushrooms/wrecks the valve stem causing further costs and grief , one from my black museum "customers 5.0 Griff with just 32k miles" many moons ago
Thanks for the warning Sardonicus, noted !Took it for a brief drive and tapping gradually stopped. Has done this before, usually the same rocker that does it. Had always assumed if it went away it was a lifter. Do you think there could be an inherent weakness in one of them or is it normal for this to happen now and then?
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