Starter motor question
Discussion
I've dug the westfield out of 'storage' and although it runs fine it doesn't start very easily. It always was a little reluctant to start but it seems to be getting worse. The engine is a 1700 xflow on twin 40s.
Basically I suspect either the battery or the starter motor. I get 13 and a bit volts from the alternator when the engine is running so the charging circuit is ok. I have a battery cut-out switch on the car so that when the car is unattended it's not draining the battery. I charged the battery over night and dropped it in the car and left it disconnected for a couple of days and it failed to start the car... the starter motor just chugged over slowly in 'steps' if you know what I mean. If I attach jump leads to another car with a happy battery is also does not start the car (same sluggish turning of the starter) but if the other car is running it spins up the starter motor and starts the westfield.
If the car is up to temperature and been running for 10 miles the battery will turn the starter motor and start the car within a fraction of a second of pressing the button.
The thing which stops me simply going out and getting a new battery (apart from the fact that this battery is only 18 months old) is that if I hold down the starter button then the earth lead gets very hot and will smoke a bit (dirt getting heated up I guess) so the starter motor must be pulling a fair drain from the battery even though it isn't turning properly.
Any idea or things to test would be gratefully received.
Thanks,
Mark
Basically I suspect either the battery or the starter motor. I get 13 and a bit volts from the alternator when the engine is running so the charging circuit is ok. I have a battery cut-out switch on the car so that when the car is unattended it's not draining the battery. I charged the battery over night and dropped it in the car and left it disconnected for a couple of days and it failed to start the car... the starter motor just chugged over slowly in 'steps' if you know what I mean. If I attach jump leads to another car with a happy battery is also does not start the car (same sluggish turning of the starter) but if the other car is running it spins up the starter motor and starts the westfield.
If the car is up to temperature and been running for 10 miles the battery will turn the starter motor and start the car within a fraction of a second of pressing the button.
The thing which stops me simply going out and getting a new battery (apart from the fact that this battery is only 18 months old) is that if I hold down the starter button then the earth lead gets very hot and will smoke a bit (dirt getting heated up I guess) so the starter motor must be pulling a fair drain from the battery even though it isn't turning properly.
Any idea or things to test would be gratefully received.
Thanks,
Mark
Any connection that is heating up is not a good connection. Clean and tighten it.
Check all the grounds as well. If it spins ok when another car is on, the starter is fine. The fact that it starts/spins ok when warm means that your battery is fine. That leaves the wires/switches between the two.
Gary
Check all the grounds as well. If it spins ok when another car is on, the starter is fine. The fact that it starts/spins ok when warm means that your battery is fine. That leaves the wires/switches between the two.
Gary
gary_tholl said:It's not the connection that gets warm but the main earth strap from the battery to the engine.
Any connection that is heating up is not a good connection. Clean and tighten it.
I'll clean all the connections and make sure they are all good and then look at the starter.
Thanks for all the advice.
Mark
If cleaning all the connections/terminals doesn't help, might be worth taking your starter motor to your local auto electrical reconditioners and ask them to test it on their rig.
At least you'll know one way or the other and can get them to fix it if that's the problem. And if it isn't then you can pick their brains for what it might be...
Edited because I just remembered something. Once had starter motor problem on my Mk1 Capri which turned out to be due to end plate screws coming loose, letting end plate move about so that internals sometimes rubbed on casing magnets. Worth checking.
>> Edited by grahambell on Friday 7th May 20:38
At least you'll know one way or the other and can get them to fix it if that's the problem. And if it isn't then you can pick their brains for what it might be...
Edited because I just remembered something. Once had starter motor problem on my Mk1 Capri which turned out to be due to end plate screws coming loose, letting end plate move about so that internals sometimes rubbed on casing magnets. Worth checking.
>> Edited by grahambell on Friday 7th May 20:38
grahambell said:Good idea, will do... thanks.
If cleaning all the connections/terminals doesn't help, might be worth taking your starter motor to your local auto electrical reconditioners and ask them to test it on their rig.
At least you'll know one way or the other and can get them to fix it if that's the problem. And if it isn't then you can pick their brains for what it might be...
One part of me wishes the car would just work and I could drive it but I think I'm enjoying tinkering with this stuff more than I do driving it
Mark
you can get a replacement starter from Cafco for about £30,but I would have a look at the cables.This did to mine and found the earth connection to the battery had broken down internally.New cables ready made from Halfords for a few quid.Also depends on how much churning the engine you are doing.The leads will get hot,but shouldn't smolder.
(In the tone of Crocadile Dundee)
Thats not an earth lead mate.....
...Now this is an earth lead:
400 amps, 15mm thick i think,Spins my 5.7 nicely! ;-)
Just looked at your picture again, put a meter between the earth on the battery and the bell housing - to see the voltage drop.
e.
>> Edited by eliot on Saturday 8th May 10:04
Thats not an earth lead mate.....
...Now this is an earth lead:
400 amps, 15mm thick i think,Spins my 5.7 nicely! ;-)
Just looked at your picture again, put a meter between the earth on the battery and the bell housing - to see the voltage drop.
e.
>> Edited by eliot on Saturday 8th May 10:04
Do what I did: buy a new battery from Halfords, try it in the car, if no difference, take it back!! I wasn't sure if the Jag not starting was a battery issue or something from my engine rebuild. Turned out that the dizzy was off. Halfords refunded my money with no questions asked!
Mind you, I think that you'll see either the engine strap or the battery -ve lead needs renewing.
Mind you, I think that you'll see either the engine strap or the battery -ve lead needs renewing.
You should see less than .5v volt drop accross it when cranking. (u need a digital meter) anything more than that, means that the cable is duff.
You can use the same technique on your positive lead.
I had one of those braided earth straps that looked ok, but i was loosing 1v accross it.
eliot.
You can use the same technique on your positive lead.
I had one of those braided earth straps that looked ok, but i was loosing 1v accross it.
eliot.
Reminds me of the time I was servicing a huge MPI machine for a crankshaft manufacturer! They clamp the crank between two copper plates and blast 6000 Amps through it, then spray with (effectively) iron filings, which show up any defects in the crank.
To calibrate the machine we install a shunt of know value in place of the crank and run the machine. We can then measure the voltage drop across the shunt which equates to the current flowing. But to install the shunt, I had to climb on the roof of the machine and disconnect the cables (welding cable thickness, three of them in parallel!) from the contact plates and bolt them to the shunt. Our cables aren't as meaty as those on the machine but for short tests they're OK.
Anyway, I did the job, handed the machine back to the operator and went on to the next machine, a paltry 3000A unit.
A few mins later the operator comes and tells me that the machine is not magnetising the cranks. Sinking feeling, what the hell have I done? So I went and had a fiddle; machine is making current, what's the problem? Thought I'd better climb up on top again so I had to override all the safety interlocks. Told the guy to keep running the machine while I went up and had a look. When I got there, I found the shunt still in place. Doh! Alas the guy was running the machine flat out, and as I arrived, the insulation on the three cables caught light and started dripping molten rubber into the machine. At the same time the copper cable was trying to melt its way through the plastic 'caterpillar' that carries all the cables, pneumatics etc. up top. I yelled at the guy to switch it off, and frantically hoisted the cables out of the plastic morass with a spanner I had in my arse pocket. The pneumatic lines burst and the noise was deafening, as it tried to empty the plant airline at me. Two machines nearby closed down because the air pressure was too low for them; the machine I was on tripped the loal distribution board because the live cables had hit the earthed chassis. Several PCs on the same phase went down. I had to stand there for several minutes holding the red hot cables in the air, about half an inch from my hand, with the spanner, until they'd cooled enough to put down. Meanwhile people were wandering round scratching their heads, I couldn't hear anything but hissing air and nobody seemed to realise I was up there.
Needless to say, I managed to 'fix' it and bullshitted the client that it was a frayed cable that caused it... but to this day whenever I climb up there I am reminded about it by the mangled caterpillar...
Ee, we 'ad fun in them days!
Ian
To calibrate the machine we install a shunt of know value in place of the crank and run the machine. We can then measure the voltage drop across the shunt which equates to the current flowing. But to install the shunt, I had to climb on the roof of the machine and disconnect the cables (welding cable thickness, three of them in parallel!) from the contact plates and bolt them to the shunt. Our cables aren't as meaty as those on the machine but for short tests they're OK.
Anyway, I did the job, handed the machine back to the operator and went on to the next machine, a paltry 3000A unit.
A few mins later the operator comes and tells me that the machine is not magnetising the cranks. Sinking feeling, what the hell have I done? So I went and had a fiddle; machine is making current, what's the problem? Thought I'd better climb up on top again so I had to override all the safety interlocks. Told the guy to keep running the machine while I went up and had a look. When I got there, I found the shunt still in place. Doh! Alas the guy was running the machine flat out, and as I arrived, the insulation on the three cables caught light and started dripping molten rubber into the machine. At the same time the copper cable was trying to melt its way through the plastic 'caterpillar' that carries all the cables, pneumatics etc. up top. I yelled at the guy to switch it off, and frantically hoisted the cables out of the plastic morass with a spanner I had in my arse pocket. The pneumatic lines burst and the noise was deafening, as it tried to empty the plant airline at me. Two machines nearby closed down because the air pressure was too low for them; the machine I was on tripped the loal distribution board because the live cables had hit the earthed chassis. Several PCs on the same phase went down. I had to stand there for several minutes holding the red hot cables in the air, about half an inch from my hand, with the spanner, until they'd cooled enough to put down. Meanwhile people were wandering round scratching their heads, I couldn't hear anything but hissing air and nobody seemed to realise I was up there.
Needless to say, I managed to 'fix' it and bullshitted the client that it was a frayed cable that caused it...
but to this day whenever I climb up there I am reminded about it by the mangled caterpillar... Ee, we 'ad fun in them days!
Ian
eliot said:
I had one of those braided earth straps that looked ok, but i was loosing 1v accross it.
I'm getting no drop over the braided earth strap but dropping 1v over the battery to chassis cable. That's the one that smokes with I crank the starter. I'll replace it.
Is that enough to stop the starter motor spinning rapidly?
Edited to add: Thinking about it it must be as when I apply 13.5v from another running car it spins over very freely. Assuming that I'd be loosing just over 1v through that lead it would leave the normal 12v to the starter. I'll replace it anyway and go from there.
Thanks,
Mark
>> Edited by dern on Sunday 9th May 15:51
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