Stumped! - new starter
Discussion
I bought a high performance starter from a reputable supplier for my 80's 3.0 alfa romeo. The original starter work OK from cold - but after a drive to fill with petrol for example there is a delay from turning key and starter turning engine, and slowly..
The replacement starter is a perfect fit and turning ignition you can hear the click as the pin fires, but engine will not turn. The workshop - long standing (30 years) specializing in AR) connected a power pack direct to new starter - same result, no joy.
Starter came off car, and on the bench work 100% - pin fires, starter spins as you'd expect. Back on car - click but not turning.
Put original starter on and engine turns.
New starter has same number of teeth on gear , the gear engages (it does not spin as if gear is not engaged when ignition is turned for example).
New starter went back to supplier and they opened, checked and tested - saying all is good.
Fitted back on car - click but not turning - fit original and it turns...
I'm lost...any thoughts?
The replacement starter is a perfect fit and turning ignition you can hear the click as the pin fires, but engine will not turn. The workshop - long standing (30 years) specializing in AR) connected a power pack direct to new starter - same result, no joy.
Starter came off car, and on the bench work 100% - pin fires, starter spins as you'd expect. Back on car - click but not turning.
Put original starter on and engine turns.
New starter has same number of teeth on gear , the gear engages (it does not spin as if gear is not engaged when ignition is turned for example).
New starter went back to supplier and they opened, checked and tested - saying all is good.
Fitted back on car - click but not turning - fit original and it turns...
I'm lost...any thoughts?
Presuming the jump pack the garage used was fully charged and in GWO then my expectation would be a faulty starter motor.
IME when powered off the car a good starter motor will try & throw itself all over the place if not fixed down so be careful when doing this at home.
If it doesn't but just spins then I would be looking for an internal fault - I had similar a couple of years ago with my Classic Range Rover.
Turn the key & you would hear the click but no turning of the engine.
Bit of an 'Oh s
t' moment as I'd just refitted the gearbox & as it was fine before I took the box off my first thought was 'What have I cocked up?!
Put another battery on - fully charged - and same result.
Connecting a battery with it off the car it would turn but no oomph.
Local specialist repairer put it on his test rig & connected direct to the main part of the starter motor it was fine but connected as normal it was the gentle spin.
I'm not sure what he replaced as it was something internal - maybe something to do with the solenoid? - but normal service was resumed.
ETA. I presume you've done the normal fully charge battery, clean terminals on battery, starter motor and all earth terminals with your original starter?
Also worth connecting a good quality jump lead direct from starter motor body to battery earth terminal just to rule out a faulty engine-to-body earth strap. Common problem esp with the plastic sheathed type, they can look fine at the ends but the middle can corrode away to nothing.
IME when powered off the car a good starter motor will try & throw itself all over the place if not fixed down so be careful when doing this at home.
If it doesn't but just spins then I would be looking for an internal fault - I had similar a couple of years ago with my Classic Range Rover.
Turn the key & you would hear the click but no turning of the engine.
Bit of an 'Oh s
t' moment as I'd just refitted the gearbox & as it was fine before I took the box off my first thought was 'What have I cocked up?!Put another battery on - fully charged - and same result.
Connecting a battery with it off the car it would turn but no oomph.
Local specialist repairer put it on his test rig & connected direct to the main part of the starter motor it was fine but connected as normal it was the gentle spin.
I'm not sure what he replaced as it was something internal - maybe something to do with the solenoid? - but normal service was resumed.
ETA. I presume you've done the normal fully charge battery, clean terminals on battery, starter motor and all earth terminals with your original starter?
Also worth connecting a good quality jump lead direct from starter motor body to battery earth terminal just to rule out a faulty engine-to-body earth strap. Common problem esp with the plastic sheathed type, they can look fine at the ends but the middle can corrode away to nothing.
Edited by paintman on Tuesday 12th October 15:16
You should be able to get a fair way through diagnosing this with a voltmeter, an ammeter would help. Depending on the design of the starter motor you may need to partially dismantle it to attach a lead to the points you want to measure, but on some these can all be made externally.
There are two windings through the solenoid. One connects between the solenoid +ve and the body of the start motor. The other connects between solenoid +ve and starter motor +ve.
When you turn the switch to the cranking position you should see close to battery voltage between the solenoid +ve and the starter body. Both solenoid -ves should stay close to ground voltage.
After the solenoid has moved to the closed position you should see see a few changes: Starter motor +ve terminal will be pulled up close to battery +ve; solenoid +ve voltage should stay close to battery +ve; the solenoid -ve that is connected to the motor +ve should now be showing close to battery +ve voltage. The starter motor should start drawing a lot of current. Battery +ve, solenoid +ve and motor +ve should all be close together and at least 10V above the battery -ve voltage. Starter motor body should be close to the battery -ve voltage.
If you don't see that then it will probably be possible to diagnose the problem based on what you actually see. I suspect you'll find that the solenoid is either too weak, or is physically prevented from closing eg by the pinion fouling something so the starter motor is never being energised, but you don't need to guess - the measurements above should show you what's going on.
There are two windings through the solenoid. One connects between the solenoid +ve and the body of the start motor. The other connects between solenoid +ve and starter motor +ve.
When you turn the switch to the cranking position you should see close to battery voltage between the solenoid +ve and the starter body. Both solenoid -ves should stay close to ground voltage.
After the solenoid has moved to the closed position you should see see a few changes: Starter motor +ve terminal will be pulled up close to battery +ve; solenoid +ve voltage should stay close to battery +ve; the solenoid -ve that is connected to the motor +ve should now be showing close to battery +ve voltage. The starter motor should start drawing a lot of current. Battery +ve, solenoid +ve and motor +ve should all be close together and at least 10V above the battery -ve voltage. Starter motor body should be close to the battery -ve voltage.
If you don't see that then it will probably be possible to diagnose the problem based on what you actually see. I suspect you'll find that the solenoid is either too weak, or is physically prevented from closing eg by the pinion fouling something so the starter motor is never being energised, but you don't need to guess - the measurements above should show you what's going on.
LimSlip said:
Would this be a modern geared starter upgrade? I had no end of issues fitting one of these to a crossflow in a kit car, it simply wasn't machanined correctly and nothing lined up well. That said Brise make some top quality stuff, as reflected in the price...
It is indeed a starter from Brise - had them recommended but I cant help to feel the issue is machining related. stevieturbo said:
reason for changing ?
And what exactly is "uprated" about it ?
Just how slowly, or not at all is it turning ?
Is the live cable to the starter 100% sound ?
Is the earth from both battery to chassis, and battery/chassis to engine all good ?
The original starter turned very slow when the car stopped for 3 minutes e.g. filling with petrol.And what exactly is "uprated" about it ?
Just how slowly, or not at all is it turning ?
Is the live cable to the starter 100% sound ?
Is the earth from both battery to chassis, and battery/chassis to engine all good ?
The starter is a high performance from Brise. https://brise.co.uk/product-category/starters/?v=7...
Starter turned very slowly when car is hot - current one 35 years old hence me deciding to change.
Workshop put a 620A pack directly to starter - turns the original no problem, but not the new one - only click as the pin fires.
Edited by coetzeeh on Tuesday 12th October 18:43
coetzeeh said:
Workshop put a 620A pack directly to starter - turns the original no problem, but not the new one - only click as the pin fires.
This is whilst attached to the engine ? Or on the bench, no load ?Presumably the engine itself is not stiff to turn over ?
A clamp meter would give an indication if the new starter is actually trying to turn something over, or just doing nothing via how much current is being drawn
stevieturbo said:
coetzeeh said:
Workshop put a 620A pack directly to starter - turns the original no problem, but not the new one - only click as the pin fires.
This is whilst attached to the engine ? Or on the bench, no load ?Presumably the engine itself is not stiff to turn over ?
A clamp meter would give an indication if the new starter is actually trying to turn something over, or just doing nothing via how much current is being drawn
Power pack attached to starter on bench and the starter spins.
No issues with engine - runs smooth, and the original starter turns the engine - workshop swapped units while I was there to demonstrate like for like.
I think this is might be an issue with the way the pin fires and somehow causes a snag preventing starter to turn.
Can you get a voltmeter onto both the high current and the solenoid connections on the back of the starter? If so then check the voltage at both of these points remains at or around 12v with the starter actuated (high current connection would drop to 10v or so if the engine was actually cranking).
If you have a high resistance in the solenoid circuit it may not be able to deliver sufficient current to fully engage the starter, in which case you'd see a voltage drop on the solenoid connection. If you have a high resistance in the main battery cable the starter may engage but have insufficient torque to crank the engine, and this would be seen as a voltage drop on the high current terminal.
You say that the pinion is engaging, is this just based on the click or have you been able to prove this? Applying something like plasticine on the ring gear teeth around the point of engagement would leave clear witness marks if the pinion really is engaging. At a pinch even grease could be used.
If you have a high resistance in the solenoid circuit it may not be able to deliver sufficient current to fully engage the starter, in which case you'd see a voltage drop on the solenoid connection. If you have a high resistance in the main battery cable the starter may engage but have insufficient torque to crank the engine, and this would be seen as a voltage drop on the high current terminal.
You say that the pinion is engaging, is this just based on the click or have you been able to prove this? Applying something like plasticine on the ring gear teeth around the point of engagement would leave clear witness marks if the pinion really is engaging. At a pinch even grease could be used.
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