Club G40 Forum
Technical => Engine and Transmission => Topic started by: G40 AD on March 17, 2010, 11:39:01 am
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hey guys n gals,
having trouble with my starter motor... its weak when turning over from cold (can take up to three turns when weathers really cold)
but the main issue is that once the engine is hot the starter is too weak to turn over the car, sounds like a flat bat (quite possible)!
I have wondered if the alternator is not quite living up to the task in hand...
from searching on here i gather that cleaning up the terminals is a good start and testing the battery, can someone tell me what readings i should be expecting across the battery when running and when not.
This happened after my last engine rebuild and i replaced the starter motor and it solved the problem... until now!!!
any suggestions welcomed!
Cheers
Ad
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test the battery, see what the voltage reads when cranking the starter. Test the big power cable from the battery to the starter. well more a case of just look at the condition of it really! Replace the starter if both those are ok.
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cheers hayesy
should i expect to see 12v on both readings?
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at least yeah.
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no longer starting even from cold!
have checked and cleaned up the connection to the battery and starter... no joy...
changed the starter motor 3 times now so confident it isnt the actual starter motor... guess the only issue could be that the non G40 starter motors will not work although i have changed previously for another starter that to my knowledge was not a G40 one but could have been.
It really sounds like a flat battery but never seems to die completely... alternator looks messy covered in gunk so who know what its like inside... again cleaned/renewed connections to alternator too...
the earth by the charger is the original but looks in fine condition...
What timing would you expect to see as standard??
any pointers welcome!!!
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does it turn over? or just click?
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so what voltage do you see across the battery?
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ps starters arent g40 specific
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turns over but very weekly...(just like a flat bat when holding the key it turnsover then goes silent then turns again and so on)
cheers for the heads up on non specific starters... (do you know if the alternators are i think they are)
just going to test battery voltage and voltage when running...
George (aka Rolo) has advised i run an extra, thick earth from the negative to a point near to the starter.
anyone recommend a good point to do so to guessing idont want it to the actual starter itself?
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tbh, sounds like a shit battery/alternator to me - alternator isnt common with other polos but is common with some weird and wonderful other stuff in the vw range.
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scirocco glx alternator is exactly the same as g40. £37 brand new of eBay - allllllright:-)
if it was doing it when hot- check the wire going from the alternator to the starter. it runs along the sump and the plastic goes manky near the clips and you may find the wire has frayed near them potentially causing a short. I replaced this cable on mine when I first bought the car as it had a hot start problem and it turned out to be this very cable doin what I just described.
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didnt manage to get a multi-meter on it tonight...
will be sure to check out my wiring again... whats the best thing to re-wrap the wiring in to protect it from the sump...
anyone know if the plastic casing from the afh that clips roundthe sump would fit the same?
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all the plastic does is protect the wire from both the heat and the snagging on what are crap clips. so you just need a semi flexible plastic tube. so if the AFH has the same sort of method - use it!
you will more likely then not find that after years of getting hot and cold- hot and cold that that plastic is fubar and the clips. may not solve the problem - but it might do!
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cant do any harm to do it... will get this sorted at the weekend... god my list for this weekedn is building very quickly!
has made me think that ever since i picked her up 3years ago the clock on the dash has intermitently reset when starting! so guess itcould be shorting!
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if it resets every now and then you do have a short mate - where ever it may be!
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right quick update...
happy to see that i got a 12v reading with the engine off and 14v with the engine on!
I can only guess though that this means it isto do with earthing as sufficient power should be going through the starter motor if the alternator can still produce 14v??? am i correct in thinking this?
going to fit new wiring now just for piece of mind!
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ok... just had the relays off and they looked a bit grubby/greeny so cleaned them and the sockets... is there a way of testing them?
just tested;
negative to starter: read 12v(engine off)
negative to alternator: read 12v(engine off)
my assumption from this is that the wiring is all ok, is this a fair assumption?
potentially it could be shorting at some point and still read 12v, correct?
going to clean up the bat terminal but cant see that i would get the 12&14v readings if a poor connection was causing trouble... grrrrrrrrrrrr..........help!
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ad have you check the earth straps around the bay?
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yeah,
charger to chasis leg
bat neg to wing
coil to gearbox
that all of them?!? is there any particular way to test them? like bat posi to far side of earth n check the voltage?
cheers,
ad
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scirocco glx alternator is exactly the same as g40. £37 brand new of eBay - allllllright:-)
if it was doing it when hot- check the wire going from the alternator to the starter. it runs along the sump and the plastic goes manky near the clips and you may find the wire has frayed near them potentially causing a short. I replaced this cable on mine when I first bought the car as it had a hot start problem and it turned out to be this very cable doin what I just described.
This true, cos if it is i'm buyin'.
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getting 12v across all the earth straps at the chasis end.....
anyone got any clues?
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is there any possibility that the relays could be at fault...
Saf said that he had the same trouble when his bat was kaput...gonna try a new bat tomo...
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replaced the battery tonight... still no joy!
gettin really fed up... someone please throw me a lifeline or am i going to have to kill yet another supercharger...
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there is 2 plugs under the right hand side (lokin at the bay) of the throttle top hat one is for the starter see if its got a good connection
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Could be the ignition switch.
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just to confirm is this the plug at the back right of the TB... just going from memory
or is it the middle plug of the three in the holder where lambada plug sits?!?!
by the ignition switch do you mean by the by the key barrel?
the cd player (run from the ignition) does keep cutting out... loose connection... could this be linked?
thanks v.much for your help guys!
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the ignition switch is on the steering column, behind where you put the key in.
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just to confirm is this the plug at the back right of the TB... just going from memory
or is it the middle plug of the three in the holder where lambada plug sits?!?!
The white plug actually on the TB is for the throttle open/closed switches so not that one. It's one of the black ones, thick red/black cable and thinner blue cable.
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will investigate this eve!!! am i just testing for the obvious poor connections etc or are there any other tests i can do?
cheers,
Ad
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no joy with the plug... think it cud be the relays... tried another bat didnt work...
how should i test the ignition? best to just remove the steering wheel cowling and check for any visible faults or perhaps with the car running wiggle the wires and see if it cuts out?!
cheers,
Ad
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can anyone give me a heads up on how to test the ignition switch?
just to be clear it is trying to turn over but very weakly does sound just like a flat bat...!
cheers...
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son las escobillas del alternador
el aparato que se encarga de cargar la bateria
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son las escobillas del alternador
el aparato que se encarga de cargar la bateria
translated =
"they are the brushes of the alternador the apparatus that takes charge of charging the bateria"
the battery is not the problem, we used it on a different car yesterday and it was fine!
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quick update,
noticed that the bracket that hold the lambada/alternator clips on the inlet was loose so cleaned up earths and surfaces and tightened. (sounded mildly stronger after this)
tried running an earth from the bat to the rocker/inlet no joy
looked at the bat on a polo coupe 1.0l fox anditappears to have two brown wirestothe negative and four red to the positive whereas mine (see below) only has one brown and three red, is this correct?
(http://i61.servimg.com/u/f61/11/91/28/17/photo010.jpg) (http://www.servimg.com/image_preview.php?i=172&u=11912817)
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Still facing this issue!
Tried tonight;
-6n starter and wiring - starter turned quickly but does not engage to fly wheel!
-two mk3 polo starters - both cranked once and gave nothing more after that (note battery just taken off my other G40 which starts everytime with no issues)
-Check over mk3 wiring for any breaks etc... all looks fine
-Turned enging over by hand with no odd noises or difficulty
Losing the will now! Got loads of proper jobs to be doing on it this weekend and this is really bugging me!
In the morning I am going to re-check earths, swap the starter and wiring from my running G40 and see what happens.
Can anyone suggest any other angles to try???
Does this sound like it could be a symptom of the radio ign. switch feed shorting somewhere? no radio in it at present but guess this wouldnt stop shorting occuring if the wiring is at fault...
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If you've not already, isolate the starter and start from the minimum and work your way up.
1st - Using jump cables (earth on starter case, live on solenoid bolt fitting) and a thick wire (from the solenoid bolt fitting to the spade connector on the solenoid, closest to the engine block when fitted), test the starter function from the battery in the car, with the starter not mounted to the block - secure it on the floor with a foot as it can give quite a kick... The starter will 'fire' when you put live on the solenoid spade connector, assuming it has earth and live too.
If this works then:
Fit the starter, but do not connect any wires from the car - use your jump cables and the thick wire to test the starter, make sure you use one of the jump cables as an earth onto the starter case.
If this works then you have a problem with the vehicle wiring somewhere.
First, remove the earth jump lead and see if it still starts when you put live on the solenoid spade connector
If this works, then re-connect the spade connector on the solenoid that goes to the ignition switch and try to start using the key
If this works then remove your live jump cable from the battery to the solenoid bolt fitting and re-fit the live wire from the battery clamp, but not the one from the alternator.
If this works, then refit the wire from the alternator
Hopefully you'll find that at the start of these troubleshooting steps when you're not using any of the vehicles wiring, the starter will work ok, but at some point along these steps it will stop working. If this happens it will point to the problem.
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thanks mate - will jump on that now! wiring isnt my favourite game and this sounds like a good bit of advice to follow! much appreciated!
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Any updates dude, I'm keen to know what the problem was?
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Could be the ignition switch.
i would go with this, me and pete had the same problem with a G40 many moons ago, as a last resort we tried the ignition switch. I have a spare i can post to you if you want.
Dead easy to swap, just undo the plastic cowelling and there is a screw on the back of the barrel unscrew it and the switch slides out.
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My money's still on starter bush in the gearbox as per PMs etc ;)
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Having read all that I'd go for a wiring/ earth fault. I'd rip the lot out and put new earths everywhere. Use the multimeter on resistance mode to check how much each cable resists and use the continuity setting to find out if any +ve's are shorting out (give them a good wiggle!) although I'd expect fuses to blow/ cable sheathing to melt/smoke if it were shorting (normally)